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Diesel Test AustraliaEmission testing, research and project management ABN 82 077 044 083

919 Londonderry RoadLondonderry NSW 2753AUSTRALIA

PO Box 4266Londonderry NSW 2753Tel: (+61) 2 4777 5315Fax: (+61) 2 4777 5316

Final Project ReportNovember 2008

EMISSIONS TESTING OF A SAMPLE OF PETROL GARDEN EQUIPMENT ENGINES

For

Department of the Environment, Water, Heritage and the Arts

Diesel Test AustraliaEmission testing, research and project management i

© Commonwealth of Australia 2008

This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth, available from the Department of the Environment, Water, Heritage and the Arts. Requests and inquiries concerning reproduction and rights should be addressed to:

Assistant SecretaryEnvironment Standards BranchDepartment of the Environment, Water, Heritage and the ArtsGPO Box 787CANBERRA ACT 2601

The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment, Heritage and the Arts or the Minister for Climate Change and Water.

While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication.

Diesel Test AustraliaEmission testing, research and project management ii

AcknowledgementsDiesel Test Australia would like to thank Honda Australia MPE Pty Ltd for the kind loan of the Dyno Dynamics small engine dynamometer used for the testing of the lawnmower engines in this project. Thanks also to Dyno Dynamics for their assistance with removal, transport, calibration and reinstallation of the dynamometer.We would also like to acknowledge our Project partner Test Safe who made workshop facilities and space within their Londonderry test facilities available and specifically, Dave Wood who fabricated the test jigs and engine mounting adaptors for the engines tested.Finally, thanks to all of those company representatives who made time to speak with us and who provided valuable local information on the characteristics of the small petrol engine market and specific data on their products.

Diesel Test AustraliaEmission testing, research and project management iii

Table of Contents_Toc214879133Acknowledgements.................................................................................................... iiList of Abbreviations .................................................................................................. vExecutive Summary................................................................................................... 11 Introduction ........................................................................................................ 4

2 International Test Standards .............................................................................. 5

2.1 Engine Classes .......................................................................................... 5

2.2 Emission Limits .......................................................................................... 52.2.1 Emissions Deterioration Factors ............................................................. 72.2.2 Emissions Averaging, Banking, and Trading........................................... 7

2.3 Engine Test Cycle ...................................................................................... 8

3 Selection of Garden Equipment for Testing........................................................ 9

4 Test Equipment and Methodology.................................................................... 12

4.1 Test Fuel and Oil...................................................................................... 12

4.2 Test Equipment ........................................................................................ 134.2.1 Lawnmower Engine Dynamometer....................................................... 134.2.2 Handheld Engine Dynamometer........................................................... 144.2.3 Sampling and Analytical Equipment ..................................................... 14

4.3 Test Procedure......................................................................................... 17

5 Testing Results ................................................................................................ 18

5.1 Emission Results Summary...................................................................... 18

5.2 Lawnmower Emissions Data .................................................................... 205.2.1 4-stroke Lawnmowers .......................................................................... 205.2.2 2-stroke Lawnmowers .......................................................................... 225.2.3 Comparison of Tested Lawnmowers Emissions Data to Certified Engines

235.2.4 Lawnmower Emissions Data Repeatability ........................................... 255.2.5 Lawnmower Engine Power Data........................................................... 25

5.3 Handheld Engine Emission Data.............................................................. 275.3.1 Comparison of Tested Handheld Engines Emissions Data to Certified

Engines ................................................................................................ 305.3.2 Handheld Engine Emissions Data Repeatability ................................... 325.3.3 Handheld Engine Power Data .............................................................. 33

5.4 Comparison of Test Data from Certified Engines Tested to Original Certification Data...................................................................................... 34

6 Conclusions ..................................................................................................... 36

Appendix 1: Engine Certification Labels and Documentation .................................. 39Appendix 2: Complete Test Data ............................................................................ 43

Diesel Test AustraliaEmission testing, research and project management iv

Index of Figures

Figure 4-1: Dyno Dynamics Lawnmower dyno with Honda GCV160 fitted .............. 13Figure 4-2: Magtrol dyno with Echo brushcutter installed ........................................ 14Figure 4-4: Full flow dilution tunnel ......................................................................... 16Figure 5-1: Four Stroke Lawnmower Data Summary for CO, CO2 & BSFC............. 21Figure 5-2: Four Stroke Lawnmower Data Summary for THC, NOx & THC+NOx..... 21Figure 5-3: Two-Stroke Lawnmower Data Summary............................................... 22Figure 5-4: Comparison of Average Emissions from Tested Lawnmower Engines to

Average Emissions from all Certified Engines in the US EPA Database .... 23Figure 5-5: Comparison of Average Emissions from Tested 4-stroke Lawnmower Engines to Average Emissions from all Certified Engines in the US EPA Database 24Figure 5-6: Handheld Engine Emissions Data Summary, all except NOx ................ 29Figure 5-7: Handheld Engine Emissions Data Summary, NOx ................................ 30Figure 5-8: Comparison of Average Emissions from Tested Handheld Engines to

Average Emissions from all Certified Engines in the US EPA Database .... 31Figure A1-1: Echo SRM2305SI Certification Plate .................................................. 39Figure A1-2: Briggs and Stratton XM50 Certification Plate...................................... 39Figure A1-3: Husqvarna 125L Certification Plate .................................................... 40Figure A1-4: Ryobi PLT3043YW Certification Plate ................................................ 40Figure A1-5: Stihl FS45 Certification Plate.............................................................. 40Figure A1-6: Stihl FS45 CARB Certification ............................................................ 41Figure A1-7: Husqvarna 125L CARB Certification................................................... 42

Index of Tables

Table 2-1: Regulatory Engine Classifications............................................................ 5Table 2-2: Summary of US EPA and EU Emission Limits (g/kW.hr).......................... 6Table 2-3: Engine Test Cycles.................................................................................. 8Table 3-1: List of Engines Tested ........................................................................... 11Table 4-1: Analysis of Test Fuel.............................................................................. 12Table 4-2: List of Gaseous Analysers ..................................................................... 16Table 5-1: Average Weighted Emission Results for all Test Engines...................... 19Table 5-2: 4-stroke Lawnmower Results Compared to US/European

Regulated Emission limits ..................................................................... 20Table 5-3: Repeatability of Lawnmower Emission data relative to mean result ....... 25Table 5-4: Measured and Claimed Power of Lawnmower Engines ......................... 26Table 5-5: Handheld Engine Results Compared to US/European

Regulated Emission Standards ............................................................. 28Table 5-6: Repeatability of Handheld Emission data relative to mean result ........... 32Table 5-7: Measured and Claimed Power of Handheld Engines ............................. 33Table 5-8: Test Data compared to Certification Data .............................................. 34

Diesel Test AustraliaEmission testing, research and project management v

List of AbbreviationsBSFC Brake Specific Fuel Consumption, grams per kilowatt.hrCARB Californian Air Resources BoardCO Carbon MonoxideCO2 Carbon DioxideDEWHA Department of the Environment, Water, Heritage and the ArtsDF Deterioration FactorEDP Emissions Durability PeriodEPA United States Environment Protection AgencyEU European UnionEuro European emission control regulationsFEL Family Emission Levels

Oxides of NitrogenNOxTHC Total (unburnt) Hydrocarbons

Diesel Test AustraliaEmission testing, research and project management 1

Executive SummaryThis project was commissioned by the Commonwealth Department of the Environment, Water, Heritage and the Arts (DEWHA) to undertake a pilot program to test and report on the emissions from small petrol powered engines commonly used in domestic garden equipment.The objectives of the project were to:1. Obtain information on the environmental performance of small engines that

are not certified to North American or European emission regulations, based on emission testing of a sample of these engines.

2. Understand the environmental performance of the tested engines in relation to the performance of small engines which are certified to North American and European regulations.

The emissions information gathered in this project will assist DEWHA in assessing the impact of small engine emissions on urban air quality.Engines were tested using a methodology closely based on the procedures specified by the United States Environmental Protection Agency (EPA) and the European Union (EU). The test method in this study included some minor variations from the EPA certification methods. The impact of the variations on the emission results are estimated to be of order ±5%. Hence in comparing test results to EPA and EU regulated limits, this tolerance must be taken into account. However, the methodology used to test all engines in this study was consistent and hence direct comparison of the various engines tested in this study is valid. Durability testing to determine emissions Deterioration Factors required under Phase II regulations was not conducted in this project.Gaseous emissions of carbon monoxide (CO), carbon dioxide (CO2), total unburnt hydrocarbons (THC) and oxides of nitrogen (NOx) were measured. Brake specific fuel consumption (BSFC) was calculated by the carbon balance method.A total of 22 engines were tested in the project; 8 lawnmower engines (six 4-stroke and two 2-stroke) and 14 handheld 2-stroke engines (line trimmers, brushcutters, blowers and hedgetrimmers). Of these engines, one 4-stroke lawnmower was Phase I certified, two handheld engines were Phase I certified and two were Phase II certified. The sample size combined with the variability of results obtained should be taken into account in any attempt to apply the results of this project to the entire Australian small petrol garden equipment market.The testing program has demonstrated that the emissions performance within engine categories varies significantly. The variation in performance is likely to be caused by differences in the engines’ air-fuel ratio settings, the design of the carburettors affecting the air-fuel mixture preparation quality, other engine design factors, and manufacturing tolerances.The testing program also indicates that, as a class, engines tested which are not certified to US or European standards produced greater emissions than those engines certified to US or European standards. These results indicate


that significant reductions in air pollutant emissions may be achieved by requiring all new engines to meet the US/EU exhaust emissions limits.

LawnmowersLarge variation in the emissions performance of the 4-stroke lawnmower engines was observed, most notably in respect to total hydrocarbon emissions (THC). There was also substantial variation in emissions of carbon monoxide (CO) and oxides of nitrogen (NOx).Despite the variation in CO emissions, all 4-stroke lawnmower engines tested produced CO emissions that were significantly lower than the Phase I limit. Three of the engines tested also produced results below the combined THC+NOx emission limits of EPA and EU Phase I. Of these three engines, only one is actually certified to that standard. It was not possible to compare the test results directly to the Phase II limits1.The 2-stroke lawnmowers tested greatly exceeded the Phase I emissions limits. THC emissions were very high relative to the performance of the 4-stroke engines. Both 2-stroke engines produced THC emissions above 240 g/kW.hr in comparison to the 4-stroke lawnmowers which were all below 25 g/kW.hr. NOx emissions were much lower than for the 4-stroke engines and contributed insignificantly to the combined THC+NOx emissions. CO emissions from the 2-strokes were at least 33% above the Phase I limit in comparison to the 4-stroke lawnmowers, all of which produced results that were significantly below this limit.Comparison of the emission results averaged over all of the seven uncertified lawnmower engines tested in this project to the averages for all of the Phase I and all of the Phase II engines of this class listed in the US EPA certification database indicated much lower emissions for the certified engines. The average CO emissions for the Phase I and Phase II engines listed in the EPA database were 365 and 351 g/kW.hr respectively in comparison to an average of 450 g/kW.hr measured for the uncertified engines. For THC+NOx, the differences are greater with the Phase I and Phase II EPA listed engines averaging 10.6 and 12.2 g/kW.hr respectively compared to the average of 89 g/kW.hr measured for the uncertified engines in this project. The very high THC emissions of the 2-stroke engines in this project contribute greatly to this large difference, however, the EPA listed engines were still lower emitting than the 4-stroke engines tested in this project, which averaged 18.5 g/kW.hr THC+NOx.Hence, based on the comparison of results from the sample of engines tested in this program to engines already certified in the US, if all new lawnmowers were required to meet the limits specified in the US/European regulations, substantial reductions in CO and THC emissions would be expected,. In particular, large CO and THC reductions would result from the regulation of the 2-stroke engines, which emitted far higher than the 4-strokes. On the other hand, the establishment of US emission limits for are not expected to

1 Emission deterioration factors are required to be applied to emission result prior to comparison to the standard, and these were not determined in this project. See section 2.2.1and 5.2.1 for further discussion.


lead to reductions in NOx emissions. No trend in NOx emissions was identified between the 4-stroke engines tested which were above and below the emissions limits for the other pollutants. NOx emissions from the 2-stroke engines were however significantly lower than the US limits.

Handheld enginesThe emissions performance also varied substantially between the 14 handheld engines tested. The particularly large variation in emissions was influenced by 2 engines having significantly higher emissions than the other engines tested. Of the 14 engines tested, two were Phase I certified and two were Phase II certified.Twelve of the engines produced results that were well below the Phase I CO limits, while all were below with the Phase I NOx limit. Eight of these engines also produced results below the Phase I THC emission limits (this includes the two Phase II certified engines).In contrast only one of the two Phase II certified engines produced results below the Phase II combined THC+NOx limit. The other Phase II engine is certified in the US under averaging, banking and trading provisions to a level significantly higher than the Phase II limit. The engine tested in this project produced emissions of a similar order to the US EPA certification data listed for this model.Comparison of the emission results averaged over all of the ten uncertified handheld engines tested in this project to the averages for all of the Phase I and all of the Phase II engines of this class listed in the US EPA certification database again indicated that certified engines as a class produced much lower emissions than uncertified engines. The average CO emissions for the Phase I and Phase II engines listed in the EPA database were 333 and 260 g/kW.hr respectively in comparison to an average of 412 g/kW.hr measured for the uncertified engines in this project. For THC+NOx, the differences are greater with the Phase I and Phase II EPA listed engines averaging 166 and 61 g/kW.hr respectively compared to the average of 284 g/kW.hr measured for the uncertified engines in this project.Again, if emissions standards were in place for new handheld engines and, taking into account the sample size in this project, reductions in emissions could be expected based on the results from this testing program. This would be particularly the case if handheld engines were required to meet Phase II emissions limits.All of those engines tested which did not meet the Phase I emissions limits failed against the THC limit and therefore THC emissions would likely be reduced if a requirement to meet Phase I standards were in place. Requiring engines to meet the Phase II standards would generate far more substantial reductions in THC. All engines (except those certified to Phase II) emitted THC at levels at least 3 times the combined THC+NOx limit specified under Phase II standards. The NOx emissions from these engines were low and contributed insignificantly to this limit. There was wide variation in the CO emissions from handheld engines tested, although the majority produced results below the Phase I and Phase II limits.


1 IntroductionThis project was commissioned by the Commonwealth Department of the Environment, Water, Heritage and the Arts (DEWHA), with the project brief being to undertake a pilot program to test and report on the emissions from small petrol powered engines commonly used in domestic garden equipment.The objectives of the project were to:

1. Obtain information on the environmental performance of small engines that are not certified to North American or European emission regulations, based on emission testing of a sample of these engines.

2. Understand the environmental performance of the tested engines in relation to the performance of small engines which are certified to North American and European regulations.

Typically, the small engines utilised in garden equipment emit far higher specific emissions than those of modern road vehicles. Carbon monoxide and total hydrocarbons (THC) in particular can be several orders of magnitude higher than for modern road vehicles. The high emissions of THC can contribute to formation of photochemical smog. The emissions information gathered in this project will assist DEWHA in assessing the impact of small engine emissions on urban air quality.A total of 22 engines were tested in the project, 8 lawnmower (six 4-stroke and two 2-stroke) and 14 handheld 2-stroke (line trimmers, brushcutters, blowers and hedgetrimmers). Gaseous emissions of carbon monoxide (CO), carbon dioxide (CO2), total unburnt hydrocarbons (THC) and oxides of nitrogen (NOx) were measured, and brake specific fuel consumption (BSFC) was calculated by the carbon balance method.This report presents the details of the engines tested, the test procedures and the emissions results. The emission results are compared to both Phase I and Phase II EPA and EU regulations to allow assessment of the likely impact these regulations would have on the emissions of these types of engines, should the regulations be adopted in Australia.


2 International Test StandardsUS EPA, CARB and EU regulations for non-road engines of less than 19 kW output all share common test procedures, and in the case of the EPA and the EU, common emission limits although with differing introduction dates. CARB has slightly differing limits and engine classifications applied to the same test procedure.

2.1 Engine ClassesThe classification of engines governed by these regulations is listed in Table 2-1. Prior to 2000, CARB used essentially similar engine classes to EPA and EU although no distinction was made between handheld (line trimmers, brushcutters etc) and non-handheld (lawnmowers, small generators, pumps etc). Subsequent to 2000, CARB classified engines according to engine displacement (cc) and in some cases output shaft orientation (horizontal; typically pumps, generators etc, and vertical; typically lawnmowers).

Table 2-1: Regulatory Engine Classifications

EPA and EU CARBEngine size EPA Class EU ClassNon-handheld Engine Size

CARB ClassPre 2000

< 66 cc I-A SN:166 to < 100cc I-B SN:2100cc to < 225cc I SN:3

65cc to < 225cc I

>=225cc II SN:4 > 225cc IIHandheld< 20 cc III SH:1 < 20 cc III20 to < 50cc IV SH:2 20 to < 50cc IV

>= 50cc V SH:350 cc to <

65cc V

2.2 Emission LimitsThe emission limits specified by the US EPA and EU are summarised in Table 2-2. The emission limits are specified in grams per kilowatt hour (g/kW.hr). Note that the US EPA Phase II limits were phased in over several years; for simplicity the limits shown are those of the fully implemented Phase II standard. In the EU, these same Phase II limits were introduced in one step change from the preceding Phase I.The CARB limits are not presented in this report to avoid confusion. Although in general the CARB limits are of similar or identical magnitude, the variation of introduction dates and engine classes from the EPA and EU makes comparison difficult. Also note that the CARB jurisdiction is relatively insignificant to that covered by the EPA and EU regulations, and hence the regulation is of lesser global relevance.


Table 2-2: Summary of US EPA and EU Emission Limits (g/kW.hr)Phase I Phase IIEngine

Classes Engine Type CO THC NOx THC+NOx EPA From EU From CO THC+NOx EPA From1 EU FromI-A/SN:1 Non-Handheld 519 NA NA 50 1997 11 Aug 2004 610 50 2001 1 August 2004I-B/SN:2 Non-Handheld 519 NA NA 40 1997 11 Aug 2004 610 40 2001 1 August 2004I/SN:3 Non-Handheld 519 NA NA 16.1 1997 11 Aug 2004 610 16.1 1 Aug 2007 1 August 2007II/SN:4 Non-Handheld 519 NA NA 13.4 1997 11 Aug 2004 610 12.1 2005 1 August 2006III/SH:1 Handheld 805 295 5.36 NA 1997 11 Aug 2004 805 50 2005 1 August 2007IV/SH:2 Handheld 805 241 5.36 NA 1997 11 Aug 2004 805 50 2005 1 August 2007V/SH:3 Handheld 603 161 5.36 NA 1997 11 Aug 2004 603 72 2007 1 August 20081 – EPA Phase II limits were phased in over sev eral years, dates shown are for full implemented Phase II limit

For further detail of the regulations, the reader is directed to:• EPA: Code of federal regulations, 40CFR Part 90• EU: Directive 97/68/EC 16th December 1997, amended by directive 2002/88/EC 9th December 2002• CARB: California Code of Regulations, Title 13, Division 3 (Air Resources Board), Chapter 9 Off-Road Vehicles And Engines

Pollution Control Devices, article 1, Small Off-Road Engines


2.2.1 Emissions Deterioration FactorsPhase II regulations for both EU and US EPA require that a Deterioration Factor (DF) is applied to the emission test results to account for any emission increase across the certified life of the engine. The DF may be determined in various ways, and takes the form of a multiplier of greater than or equal to 1.0, applied to the emission results measured by the certification test. Emissions DF are required to be applied to the measured emission results of engines prior to comparison to the limits in Table 2-2 when certifying to the Phase II. Hence, the effective limits are generally lower than that shown. DF are not required to be applied for Phase I certification.Small volume manufacturers (<5000 units within each engine family annually) may elect to use generic DF specified in the regulations. All other manufacturers must test an engine (or multiple engines) representing the engine family after the emissions stabilisation period (<=12hours), and then repeat the test after the declared Emissions Durability Period (EDP). The final test emission factors are divided by the original to generate the engine specific DF. If this factor is less than one, the DF is set to 1.0.Deterioration factors were not determined for the engines tested in this project.

2.2.2 Emissions Averaging, Banking, and TradingEmissions averaging, banking and trading (ABT) provisions were introduced under the US EPA Phase II regulations. No ABT is provided within the EU regulations.Averaging allows manufacturers to exchange emission credits between engine families within their product line such that when averaged, the total volume weighted emissions of all models produced meet the emission limits. That is, emission credits are generated by one engine family certifying below the limits, and these credits are transferred to another engine family which does not meet the limits, but is then allowed to certify to higher Family Emission Levels (FEL) declared by the manufacturer.Banking allows a manufacturer to retain, or bank, emission credits generated by engines certifying below the limits. These credits may then be subsequently used in a future model year to certify other engine models that do not meet the applicable limits, or they may be traded with other engine manufacturers.


2.3 Engine Test CycleThe following test cycles are specified by the US EPA and the EU standards:

Table 2-3: Engine Test Cycles

Non-HandheldsUS Cycle A (US Engine classes I-B, I, II)EU Cycle G1 (EU Engine Classes SN:1,SN:2,SN:3,SN:4)Mode 1 2 3 4 5 6Speed Intermediate1 IdleLoad 100% 75% 50% 25% 10% 0%Weighting Factor 0.09 0.2 0.29 0.3 0.07 0.05HandheldsUS Cycle C (Engine classes I-A, III, IV, V) EU Cycle G3 (EU Engine Classes SH:1,SH:2,SH:3)Mode 1 2Speed Rated IdleLoad 100% 0%Weighting Factor Phase I2 0.9 0.1Weighting Factor Phase II2 0.85 0.15

1 – Intermediate speed is defined to be 85% of the speed at which maximum power is produced2 - Phase I weighting factors were applied to calculate cycle weighted results for the uncertified and Phase I ceritified handheld engines; Phase II weighting factors were applied to the Phase II engines

Emissions are measured and calculated as grams per hour for each individual mode listed in Table 2-3, to which the weighting factors are applied to determine the overall test result in grams per kilowatt hour (g/kW.hr).


3 Selection of Garden Equipment for TestingThe list of equipment to be tested was compiled taking into account the project guidelines below:

• Focus on lawnmowers and small handheld equipment such as line trimmers, brushcutters and blowers, which are marketed for domestic use.

• Selection of models representing the largest selling brands.

A selection of 17 non-certified engines and 5 certified engines was included in the testing, comprising:

CategoryEngine Type Handheld Lawnmower

Non-certified Certified Non-certified CertifiedTwo Stroke 10 4 2 -Four Stroke - - 5 1Total 10 4 7 1

The certified engines were included in addition to the original project requirements to enable comparison of the actual tested emissions to the relevant emissions standards, and where possible, with the certification data listed for that particular engine model. The purpose of this was twofold. It would provide insight into the actual performance of a randomly selected sample of certified engines relative to the official certification data, and this in turn would give a greater degree of confidence in the emissions results obtained and provide a benchmark with which to compare the performance of the uncertified engines.

To determine the engine list, information was gathered through:• Consultation with a garden equipment retailers, regarding most popular

models for domestic use• Consultation with garden equipment manufacturers representatives

and importers• Discussions with purchasing manager for Bunnings Hardware Penrith

branch, regarding the models available through their stores and which are the highest selling models

• Consultation with the chairman of the Outdoor Power Equipment Association to identify equipment models with high sales volumes that are not certified to an international standard

• Consultation with DEWHA departmental project manager.

The selected test engines are presented in Table 3-1. It was notable that in general, it was difficult to obtain reliable information on the emission certification status of many engines investigated. Some engines that a previous consultancy commissioned by DEWHA had identified as uncertified


were found to be certified, and many manufacturers agents and wholesalers did not appear to have knowledge of this aspect of the products specification.Of those engines tested, only the Husqvarna 125L brushcutter, Stihl FS45 linetrimmer, and Briggs and Stratton lawnmower engines had clear US EPA certification plates affixed. The Echo brushcutter was confirmed by the Australian Echo representatives to be compliant with EU Phase I after completion of testing, contrary to earlier enquiries which had indicated it was uncertified. The importer of the Ryobi PLT3043YW linetrimmer advised this engine to be uncertified, however, it was later found there was an EU certification plate on the engine (similar to the Echo) which would suggest it is also certified to EU Phase I.Further, although the Stihl is certified to the EPA Phase II regulations, it does not meet the emission limits directly, but is certified to higher allowable Family Emission Levels specified by the manufacturer under the averaging, banking and trading provisions of the regulations (40 CFR Part 90 subpart C).Photographs of the name plates of the engines confirmed to be certified are shown in Appendix 1. Copies of the CARB certification document are also presented in Appendix 1. US EPA certification certificates are not readily available; however the certification database may be sourced at http://www.epa.gov/otaq/certdata.htm#smallsi.


Table 3-1: List of Engines TestedEquipment Type Engine Class Make Model

Engine Type Eng. Make Eng. Model

Country of Origin

YOMDisp.

ClaimedPower @ RPM Certification

Handheld EPA EU (cc) (kW)Brushcutter IV SH:2 Echo SRM2305SL 2 stroke Echo NA Japan NA 21.2 0.57 7500 EU Stage I2,3

Brushcutter IV SH:2 Husqvarna 125L 2 stroke Husqvarna NA USA 2006 24.5 0.9 9000 EPA Stage II, CARB 20062

Brushcutter IV SH:2 Sanli BCS260 2 stroke Sanli NA China 2006 26.0 0.71 6000 NoneLine trimmer IV SH:2 Ryobi PLT3043YW 2 stroke Ryobi NA China1 2007 30 0.78 NA EU Stage I2,4

Line trimmer IV SH:2 Ryobi PLT2543YW 2 stroke Ryobi NA China1 2006 25 0.75 NA NoneLine trimmer IV SH:2 Homelite HLT26EDN 2 stroke Homelite Powerstroke China 2007 26 0.65 NA NoneBrushcutter IV SH:2 GMC LTP25SS 2 stroke Unknown NA China 2007 25.4 NA 9000 UnknownHedge Trimmer IV SH:2 GMC PHT22 2 stroke Unknown NA China 2007 22.5 NA NA UnknownBrushcutter IV SH:2 Star Products CG330A 2 stroke Unknown 1E36F-2A China 2006 32.6 0.9 6500 UnknownLine trimmer IV SH:2 Victa TTB2226 2 stroke Unknown NA China 2007 26.0 NA NA NoneBrushcutter IV SH:2 Talon AT33581 2 stroke Jenn-Feng Ind. NA China 2007 28 0.75 NA EU Stage IBlower IV SH:2 Talon AB320325 2 stroke Jenn-Feng Ind. NA China 2007 32 NA NA UnknownBrushcutter IV SH:2 MTD BC233-60001RS 2 stroke Maruyama NA Japan NA 22.5 0.59 7000 Unknown Line Trimmer IV SH:2 Stihl FS45 2-stroke Stihl NA USA 2007 27.0 0.75 NA EPA Phase II2

LawnmowersLawnmower I SN:3 Victa Tornado TMS482A 2 stroke Victa VE50 Australia 2007 160 NA NA NoneLawnmower I SN:3 Victa Mustang MCS482 2 stroke Victa VEX160 Australia 2007 160 NA NA NoneLawnmower I SN:3 Sanli PCS400 4 stroke Sanli OHV 400 China NA NA 2.8 NA None

Lawnmower I SN:3 Talon Eagle 18" AM3040 4 stroke Talon Surefire 145 China 2006 145 2.6 3000 EPA Phase II, Euro Stage I5

Lawnmower I SN:3 GMC RCS500 4 stroke GMC ECO 4 China 2007 NA NA 3000 UnknownLawnmower I SN:3 Miller Falls S510T Easymo 4 stroke Unknown NA China 2007 139 3.6 NA Unknown

Lawnmower I SN:3 Victa Tornado TMS484A 4 stroke Briggs & Stratton QuantumXM50 US/China 2007 190 NA NA EPA Phase I, Euro Stage I 2

Lawnmower I SN:3 Rover Big Honcho 4 stroke Honda GCV 160 USA 2005 160 4.1 NA None1 - Manufactured in China under original license to Ryobi Japan, howev er design updated by Techtronics out of Hong Kong2 – Certification plates attached to engines; information relating to certification status for all other engines obtained via direct communication with Australian manufacturer’s representatives.3 – Discovered/confirmed to be certified after completion of testing4 – Not certified according to information supplied by the importers, however has a reference to the EU regulation e1*97/68SH2 on name plate5 – Certification information obtained from manufacturer’s representatives in Australia; no certification plates attached to engine


4 Test Equipment and MethodologyThe garden equipment engines were tested using a methodology closely based on the procedures specified by the United States Environmental Protection Agency (EPA) and the European Union. The test method in this study included some minor variation from the EPA certification methods. The impact of the variations are estimated to have an impact of order ±5% on the emission results. Hence in comparison of the results to the regulated limits, this tolerance must be taken into account. However, the methodology used to test all engines in this study was consistent and hence direct comparison of the various engines tested in this study is valid.

4.1 Test Fuel and OilA single batch of commercial unleaded fuel was used for all testing in this project. A fuel analysis has been performed and is presented in Table 4-1. The test fuel met all regulated limits under the Fuel Quality Standards Act 2000, however, it should be noted that this fuel does not meet the specifications required by either the EU or US EPA regulations as shown in Table 4-1. The most notable deviation is the Reid Vapour Pressure (RVP), which at 66 kPa exceeds the maximum specified of 60-61.3 kPa in the regulations. RVP primarily affects evaporative emissions and is not expected to impact tail pipe emissions to any degree within the context of this project. The distillation curve of the test fuel had only minor deviations from the regulations, and there were also minor deviations from the olefin specification. None of these variations from the regulated specification are expected to have more than a few percent impact on the results relative to the use of certification fuel.

Table 4-1: Analysis of Test Fuel

°C

°°

Parameter Analysis Method

Aust Fuel Std Limits

Aromatics ASTM D1319 45.0 MaxOlefins ASTM D1319 18.0 MaxResearch Octane ASTM D2699 91.0 MinNumberMotor Octane Number ASTM D2700 81.0 MinReid Vapour Pressure ASTM D323 ReportBenzene ASTM D3606 1.0 MaxEthanol ASTM D4815 10 MaxOxygen ASTM D4815 2.7 MaxSulphur ASTM D5453 150 MaxIBP ASTM D86 NAT10 ASTM D86 NAT50 ASTM D86 NA

T90 ASTM D86 NA

Distillation FBP ASTM D86 210 Max

Emission Reg Limits Units ResultUS EU32 4 28-40 Vol % 28.99.2±4 <10 Vol % 16.3

Av RONAnd MON87.3±0.5

>95 - 91.6

>85 - 82.460±1.3 56-60 kPa 66.0<1.5 <1 Vol % 0.8- - Vol % <0.20- <2.3 Mass % <0.20<339 <100 Mg/kg 3332.8±11 24-40 28.253±5.5 - C 45.3103.3±5.5 E100

49-57%C 92.9

165.5±5.5 E15081-87%

°C 160.1

<212.8 190-215 °C 192.8

±

One batch of Victa Formula V two-stroke oil (manufactured by Valvoline) was used to prepare all two-stroke test fuel.


One batch of Bynorm SAE 10W/30 four stroke engine oil was used for all the four stroke lawnmower engines. This oil is widely available through hardware chains and specialist mower shops.

4.2 Test Equipment

4.2.1 Lawnmower Engine DynamometerA Dyno Dynamics 120EA engine dynamometer was used to test the lawnmower engines. This is a small eddy current dynamometer manufactured specifically for engines in the 2-20 kW range. The dynamometer (“dyno”) was calibrated by Dyno Dynamics immediately prior to the test program. Figure 4-1shows the dyno with the Honda GCV160 engine fitted, and exhaust capture installed.

Figure 4-1: Dyno Dynamics Lawnmower dyno with Honda GCV160 fitted

The standard air intake systems and exhaust systems as fitted to the engines in the assembled garden equipment were used. No additional air cooling of the test engines was used.


• A small Magtrol hysteresis dynamometer was used for testing of the handheld equipment engines. Figure 4-2 shows the Magtrol dyno with the Echo SRM2305SI installed for testing.

4.2.2 Handheld Engine Dynamometer

Figure 4-2: Magtrol dyno with Echo brushcutter installed

4.2.3 Sampling and Analytical Equipment4.2.3.1 Full Flow Dilution SystemA full flow dilution system was utilised to measure the gaseous exhaust emissions. A schematic of the generic full flow dilution system is shown in Figure 4-3. The actual test system is shown in Figure 4-4.A centrifugal blower was used to draw exhaust and dilution air into the dilution tunnel at the engine exhaust. The flow measurement of the dilution tunnel did not conform to the standard equipment methodologies of the US EPA and EU regulations, however did meet the propane recovery verification requirements of the regulations, thereby providing equivalent results.A background dilution air sample was taken in close proximity to the exhaust capture at the engine during each mode of the test, and was used to correct the gaseous emissions measurements in accordance with the requirements of the regulations.


Figure 4-3: Schematic of Test System

THC/NOx

CO/CO2

FlowMeasurement

Dilution Tunnel

Test EngineDynamometer

Heated Enclosure Heated

Line

Dilution Fan

Data Acquisition

Ambient Port for hangup checks

Filter

Background bag

Background sample


Heated filter for THCExhaust capture at engine

Filter for CO/CO2 sample

Heated THC sample line

Dilution Tunnel

Figure 4-4: Full flow dilution tunnel

4.2.3.2 Analytical SystemGaseous emissions of carbon monoxide (CO), carbon dioxide (CO2), total (unburnt) hydrocarbons (THC) and oxides of nitrogen (NOx) were measured with laboratory grade analysers meeting the requirements of the US EPA and EC regulations.The analysers are listed below:

Table 4-2: List of Gaseous AnalysersEmission Specie Analyser Model Measurement PrincipleCO Horiba AIA-240 and/or Fisher

Rosemount NGA 2000Non-Dispersive Infrared(NDIR)

CO2 Horiba AIA-240 NDIRTHC Fisher Rosemount NGA 2000 HFID Heated Flame Ionisation

Detector (HFID)NOx Fisher Rosemount NGA 2000 Heated Chemiluminescence

Detector (CLD)

Two separate sample lines are used; one for the NDIR analysers and a second for the THC and NOx as shown in Table 4-2. The CO and CO2 sample is conditioned through filters and a chiller to provide a measurement on a dry sample basis. The sample line for the THC and NOx was heated to 190°C and is filtered within a heated enclosure at 190°C. The THC is measured on a wet basis, the NOx on a dry basis. Hang up checks were conducted on the THC analyser system immediately following the test cycle as per US 40CFR90.411(a).


The brake specific fuel consumption (BSFC) was calculated by a carbonbalance from the CO, CO2 and THC measurements as shown in Equation 1.Equation 1: Calculation of Brake Specific Fuel Consumption

(0.429×CO(g /kW.hr) +0.273×CO2(g / kW.hr)+0.866×THC(g / kW.hr))BSFC(g / kW.hr) =0.866

The divisor of 0.866 is the mass fraction of carbon in the fuel based on a hydrogen to carbon ratio of 1.85:1; similarly the multipliers in the top line represent the mass fraction of carbon in the respective compound.No correction was made for the very slight change in fuel density or hydrogen to carbon ratio caused by the oil in the two-stroke mixes. The impact of the oil on the calculated fuel consumption is considered negligible, and the 2-stroke fuel consumption may be directly compared to that of the 4-stroke engines.

4.3 Test ProcedurePrior to testing each engine was subjected to a run-in period of approximately one hour at full load at approximately test speed. The emissions, power and speed data were logged for this operation. Subsequent to the run-in, several power curves were measured to determine the test speed; 85% of the peak power speed for the lawnmower engines, and peak power speed for the handhelds.Immediately prior to each test, the engines were run at test speed and full load for a period sufficient to stabilise the engine temperatures and emission readings. Each test mode was then run for a minimum of four minutes, or until stable conditions and emissions were achieved. The emissions results were calculated from the last two minutes of each mode.A minimum of two test runs were performed for each engine. Where agreement of within approximately 10% for all emission species was not achieved between the first two runs, a third run was conducted. If the third run did not give agreement within 10% of the second run, all three results were averaged to give the final result. Where agreement of 10% was achieved between the second and third runs, these two were averaged to give the final result.


5 Testing ResultsIn the presentation and discussion of the results in this section, certification levels are referred to as (EPA) Phase I or Phase II; these are identical and interchangeable with the EU Stage I and Stage II.

5.1 Emission Results SummaryThe average weighted emission results in grams per kilowatt hour (g/kW.hr) for all engines are summarised in Table 5-1. These results are the average of two or three tests as detailed in section 4.3 above and shown in the third column of the Table. The weighted result for each test is calculated from the individual test modes (six modes for the lawnmowers, and two modes for the handhelds) by applying the regulated mode weighting factors given in Table 2-3. Phase I regulation weighting factors were applied to calculate the results for the uncertified and Phase I certified handheld engines; Phase II weighting factors were applied to the Phase II engines. Individual test data for each engine is included in Appendix 2.The emission results presented are as measured and no deterioration factors have been applied. Note that Phase I regulations do not require the application of deterioration factors (DF), while Phase II regulations require the application of a DF prior to comparison with the emission limits (see section 2.2.1).Also presented is the fuel consumption, as brake specific fuel consumption (BSFC) in g/kW.hr, representing the grams of fuel that would be consumed in one hour of operation, for each kilowatt of shaft power produced.Note that the GMC ECO4 lawnmower engine had a non-adjustable engine speed governor which prevented a proper test cycle from being conducted, and hence care should be taken when considering the results for this engine as direct comparison to the other engines and the regulation limits is not possible.The “throttle” control on this engine was in fact a choke mechanism. Operation of the “throttle” to limit engine speed and power output caused very rich running, with very large increases in CO and THC. A test was attempted usingthe “throttle” to try to achieve the required test speed and loads, however the running became so rough the engine cut out at the end of the 5th mode and would not restart due to a fouled spark plug. It is thought unlikely that most users would operate the engine in this way due to the obvious poor running. Further, although the users manual is contradictory, one of the recommendations for operation is to use the highest engine speed, designated by a hare on the “throttle” (as opposed to a turtle), which corresponds to a fully open choke flap.Hence, the test procedure was modified for the testing on the GMC ECO4 engine, whereby mode 1 was performed as per the standard at full load at the intermediate speed, and then the torque was reduced to give the required percentages of torque while allowing the governor to increase engine speed. However, even with this approach three repeats gave inconsistent results and an average of all three tests of the modified test procedure was used. Refer to the raw data in Appendix 2 for further information.


Notwithstanding the comments above, the method used to test the GMC ECO4 effectively replicates real-world operation of this lawnmower; the engine load and speed vary according to the load applied whereby at zero load the engine speed is at the maximum the governor allows and the throttle is open only a small amount, and as the load (dynamometer or grass) is increased, the governor applies more throttle in response to decreasing engine speed. Given the presumption that the certification test cycle is intended to approximate real-world usage, the GMC ECO4 results can also be considered in this context, although they not directly comparable to the emission limits or test results for the other engines.

Table 5-1: Average Weighted Emission Results for all Test Engines

1 – These results for the GMC ECO4 are not comparable to the standard or other engines, see further comments in section above.

Engine Certified# of

TestsAverage Emissions, FC (g/kW.hr)

CO THC NOx THC+NOx CO2 BSFCLawnmowers – 4-strokeHonda GCV160 No 2 389 7.36 4.18 11.5 896 483Sanli OHV400 No 2 237 6.70 5.82 12.5 1155 488Talon 145 No 2 379 15.9 4.08 20.0 1350 629GMC ECO41 No 3 271 23.2 3.92 27.1 1439 611Miller Falls No 2 442 16.4 5.01 21.4 1143 596B&S XM50 Phase I 2 386 9.61 2.91 12.5 1147 562Lawnmowers – 2-strokeVicta VE50 No 2 707 286 0.40 286 972 943Victa VEX60 No 2 723 242 0.44 242 963 903HandheldsMTD BC233 No 2 501 249 0.85 250 1141 857Ryobi PLT2543YW No 2 216 187 1.29 188 1050 625GMC PHT22 No 3 123 288 3.19 291 1588 849Sanli BCS260 No 2 56 207 4.69 212 1256 631Star CG330A No 3 448 224 0.93 225 880 723Victa TTB2226 No 2 851 439 0.71 440 939 1157Talon AT33554 No 3 473 252 0.81 253 1078 827GMC LTP25SS No 3 1043 589 0.38 589 878 1382Talon AB3201 No 3 180 223 1.45 225 1673 840Homelite HLT26EDN No 2 234 164 0.74 165 1130 637Ryobi PLT3043YW Phase I 3 263 165 1.01 166 1111 646Echo SRM2305 Phase I 2 611 250 0.67 251 955 854Stihl FS45 Phase II 3 468 135 0.70 136 920 657Husqvarna 125L Phase II 3 251 48 0.39 49 1275 574

The data in Table 5-1 are presented graphically in the following sections. Complete test data is attached as Appendix 2.


5.2 Lawnmower Emissions Data

5.2.1 4-stroke LawnmowersThe data for the six 4-stroke lawnmower engines are plotted in Figure 5-1 and Figure 5-2. Certified engines are identified in the legend by P I for Phase I certified engines and P II for Phase II. The EPA and EU Phase I and II limits are shown on the figure for reference. As discussed in section 4 an estimated tolerance of ±5% must be considered in comparison of the results from this project to the regulated limits. The emissions are not directly comparable to the Phase II limits as DF are required to be applied to the test data prior to comparing to the limits (see section 2.2.1).All of the 4-stroke mower engines tested produced emissions below the US and EU Phase I emission limits for CO. Three also produced emissions lower than the combined THC+NOx Phase I limit; the Honda, the Sanli, and the Briggs and Stratton. Of these, only the Briggs and Stratton is positively identified as certified (Phase I) with a certification plate attached to the engine (see appendix 1). The Talon was claimed to be compliant to EPA Phase II by the manufacturer, however did not have a certification plate attached to the engine and the sample tested produced emissions above the USEPA and EU limits. The GMC is not directly comparable to the standard (see section 5.1), however, it is seen to have very high THC emissions relative to the other engines, and hence is unlikely to pass were it able to be tested according to the standard.It is not possible to assess the emissions relative to Phase II limits without the determination of the specific emissions deterioration factors for these engine models tested. However, review of the 2006 US EPA certification database reveals that of the Phase II certified class I engines, 95% had CO DF of less than 1.5. Hence, there is a high probability that most of the engines tested here would pass the Phase II CO limit. Similarly for THC+NOx, the certification database indicates that 92% of Phase II certified engines had DF of less than 1.3, and hence there is a moderate possibility that the three engines tested that produced emissions below the Phase I limit would also meet the Phase II limit.The overall performance of the lawnmower engines tested relative to the US/European emission standards is summarised in Table 5-2.

Table 5-2: 4-stroke Lawnmower Results Compared to US/European Regulated Emission limits

Lawnmower Type

No. Tested

Number of Units Below Regulated limitsCO THC+NOx Overall

Phase I Phase II1 Phase I Phase II1 Phase I Phase II14-stroke 6 6 5 3 3 3 3

1 Direct comparison to Phase II limits is not possible as DF are required. Numbers shown are estimated from review of typical DF of certified engines. Refer to discussion abov e.

Overall, there is a large variation in the emissions performance between the 4-stroke lawnmower engines tested. It is seen that for CO, the highest emission result is 63% greater than the lowest, and for THC+NOx, the highest emission result is 86% greater than the lowest. The variation in performance is a combination of factors such as air-fuel ratio setting, air-fuel mixture


preparation quality (carburettor design), engine design, and manufacturing tolerances. Clearly there is potential to improve the environmental performance of the highest emitting engines in the Australian market.

1600

1439

1350

1400

1155

1143

1147

1200

Emis

sion

s (g

/kW

.hr)

1000

896

800

629

611

596

562

600

483

488

389

379

386

400

442

271

237

200

0CO CO2 BSFC

Emission Pollutant

Honda GCV160Sanli OHV400Talon 145GMC ECO4Miller FallsB&S XM50 (P I)

Phase I CO limit 519 g/kW.hrPhase II CO Limit 610

g/kW.hr

Figure 5-1: Four Stroke Lawnmower Data Summary for CO, CO2 & BSFC

30

27.1

23.2

25

Emis

sion

s (g

/kW

.hr) 21

.4

20.0

20

15.9

16.4

15

12.5

12.5

11.5

9.61

10

7.36

6.70

5.82

5.01

4.18

4.08

3.92

2.91

5

0THC NOx THC+NOx

Honda GCV160Sanli OHV400Talon 145GMC ECO4Miller FallsB&S XM50 (P I)

Phase I & IITHC + NOx Limit

16.1 g/kW.hr

Figure 5-2: Four Stroke Lawnmower Data Summary for THC, NOx & THC+NOx


5.2.2 2-stroke LawnmowersThe data for the two 2-stroke lawnmower engines is plotted in Figure 5-3. NOxdata is not presented on the figure, and is very low at 0.40 and 0.44 g/kW.hr respectively for the two engines tested. The EPA and EU Phase I and II limits are shown in the figure for reference. As discussed in section 4 an estimated tolerance of ±5% must be considered in comparison of the results from this project to the regulated limits. The emission data is not directly comparable to the Phase II limits as DF are required to be applied to the data prior to comparing to the limits (see section 2.2.1).Both 2-stroke engines produced emissions above the EPA/EU regulation limits by a very large margin. Note that the regulated emission limits for this engine class are set at a level practically obtainable for 4-stroke engines, but very difficult to achieve cost effectively for a 2-stroke.Comparing Figure 5-3 to Figure 5-1 and Figure 5-2, it is seen that the 2-stroke engines have CO emissions approximately twice that of the 4-stroke engines, while the THC emissions are more than an order of magnitude higher than the 4-strokes. Conversely, the NOx emissions of the 2-strokes is an order of magnitude lower than the 4-strokes. Two stroke engines have inherently high THC emissions due to the bypassing of incoming fuel-air mixture through the engine cylinder to the exhaust port during the scavenging phase of the engine cycle. They also often have higher CO emissions than 4-stroke engines as the fuel-air mixture is set richer to keep engine cylinder temperatures down. Hence the higher emissions of the 2-stroke engines relative to the 4-stroke engines are not unexpected.Primarily due to the very high relative THC and CO emissions, the specific fuel consumption of the 2-stroke engines is also much higher than the 4-strokes.

1200

972

963

1000

943

903

Emis

sion

s (g

/kW

.hr) 800

723

707

600

400

286

286

242

242

200

0CO THC THC+NOx CO2 BSFC

Emission Pollutant

Victa VE50Victa VEX60

Phase I CO limit519 g/kW.hr

Phase II CO Limit 610 g/kW.hr

Phase I & II THC+NOx Limit

16.1 g/kW.hr

Figure 5-3: Two-Stroke Lawnmower Data Summary


5.2.3 Comparison of Tested Lawnmowers Emissions Data to Certified Engines

The emissions averaged over the seven uncertified engines tested are compared to the averages of all Phase I (23 engines) and all Phase II (83 engines) Class I engines listed in the 2006 US EPA certification database in Figure 5-4. The data for the single Phase I certified engine tested is also shown. The NOx data is not shown as there is no separate limit for NOx for this engine class, and no NOx data is available in the certification database. Refer to Figure 5-2 for the separate NOx data for the tested engines. The range of the results in each data set is indicated by the error bars on the graph.

800

700

600

Emis

sion

s (g

/kW

.hr)

500 450

386 365 351400

300

200

88.8100

12.5 10.6 12.20

THC+NOx CO

Tested Uncert.

Cert. DBase P I

Tested Cert.

Cert. DBase P II

Figure 5-4: Comparison of Average Emissions from Tested Lawnmower Engines to Average Emissions from all Certified Engines in the US EPA

Database

The averages of the uncertified lawnmower engines tested are influenced to a large degree by the high CO, and very high THC emissions of the 2-stroke engines. The EPA database does not contain any 2-stroke engines in this engine class.It is seen that the THC+NOx average from the tested engines is very much higher than the certified engines, however the error bar also shows that the lowest emitting engine tested was of the same order as the certified engines. The sole Phase I certified engine tested is seen to be quite representative of the average of certified engines. It is also of interest to note that the average THC+NOx for Phase II US certified engines is higher than the average for the Phase I certified engines, and the highest emitting Phase II engines as indicated by the error bar, are above the limit. This may be a result of the averaging and banking allowed for Phase II engines, but not Phase I engines, which allows engines to be certified at higher certification levels than the regulated limits.


For CO, the average of the uncertified engines tested is around 25% higher than the certified engines. The errors bar indicates the highest emitting engine tested in this project is much higher than the highest emitting certified engine, and the lowest emitting certified engines are much lower than the lowest emitting engine tested in this project. Again, the single Phase I engine tested is seen to be fairly representative of certified engines.The same data is plotted in Figure 5-5 omitting the 2-stroke engines tested to eliminate the large influence of the two-stroke lawnmower engines and to compare the 4-stroke engines only.

600

500

Em

issi

ons

(g/k

W.h

r) 386400 365 351344

300

200

100

18.5 12.5 10.6 12.20

THC+NOx CO

Tested Uncert.

Cert. DBase P I

Tested Cert.

Cert. DBase P II

Figure 5-5: Comparison of Average Emissions from Tested 4-stroke Lawnmower Engines to Average Emissions from all Certified Engines in the

US EPA Database

It is seen that the average THC+NOx emissions from the uncertified enginestested is still significantly higher than the certified, although the difference is much less.For CO, it is seen that the uncertified engines tested had lower average and maximum emissions than the certified engines.This analysis indicates that should emission regulations be introduced, very large environmental benefits in terms of THC+NOx would accrue by elimination of the very high emitting 2-stroke lawnmower engines. Smaller gains would be achieved by the improvement of the 4-stroke engines which currently do not meet the overseas emission limits. CO improvements are seen likely to be less marked, and would primarily come from the improvements necessary from, or removal from the market of, the 2-stroke engines. CO from 4-stroke engines does not appear likely to improve.The magnitude of the improvement in the environmental performance of the entire Australian lawnmower engine inventory is dependent on the composition of the lawnmower market and the statistical relevance of the sample engines tested, and beyond the scope of this study.


5.2.4 Lawnmower Emissions Data RepeatabilityThe repeatability of the test data combines the repeatability of the measurement equipment and the repeatability of the test engines themselves. The minimum and maximum readings for each pollutant are presented in Table 5-3 as the minimum and maximum measurement obtained over the test repeats conducted for each engine, as a percentage of the mean result.It is seen that the repeatability of the data was very good at better than ±5% for all engines excepting the GMC ECO4. This provides a good degree of confidence in the data.The GMC ECO4 data is seen to be highly variable, which in combination with the fixed engine speed governor and the impact of that on the test cycle as discussed in section 5.1, makes it difficult to draw firm conclusions regarding the emissions performance of this engine.

Table 5-3: Repeatability of Lawnmower Emission data relative to mean result

EngineData Variation Relative to Mean

CO THC NOX CO2 BSFC

Min Max Min Max Min Max Min Max Min MaxHonda GCV160 -3% 3% -5% 5% -2% 2% 0% 0% -1% 1%Sanli OHV400 -3% 3% 0% 0% -3% 3% -2% 2% -2% 2%Talon 145 -4% 4% -1% 1% -2% 2% -1% 1% -2% 2%GMC ECO4 -22% 29% -43% 50% -21% 30% -8% 5% -8% 12%Miller Falls -1% 1% -1% 1% -5% 5% 0% 0% 0% 0%B&S XM50 (P I) -3% 3% -1% 1% -4% 4% 0% 0% -1% 1%Victa VE50 -3% 3% -4% 4% -2% 2% -2% 2% -1% 1%Victa VEX60 -1% 1% -5% 5% -1% 1% -2% 2% -1% 1%

5.2.5 Lawnmower Engine Power DataThe peak power measured for the lawnmower engines and corresponding engine speed, and the resulting test speed and power are listed in Table 5-4. The claimed power is also listed for reference. The power output of the engines has some relevance to the emissions data, in that the emissions figures expressed in g/kW.hr have the power as the divisor, and dependent on the causes of low power (such as the governor not allowing the throttle to fully open, or higher frictional losses), the emissions result may be affected.It is seen there is a wide range of measured output power. For those engines for which a claimed power figure is available, it is also seen that the measured power was significantly lower than the claimed, in some cases by as much as 50%.


Table 5-4: Measured and Claimed Power of Lawnmower Engines

EnginePeak

PowerPeak

Power Speed

Test Power

Test Speed

Claimed Power

Claimed Power Speed

(kW) (RPM) (kW) (RPM) (kW) (RPM)Honda GCV160 3.14 3100 2.22 2640 4.1 NASanli OHV400 2.16 2950 1.60 2510 2.8 NATalon 145 1.30 2400 1.05 2040 2.6 NAGMC ECO4 1.25 2500 1.2 2415 NA NAMiller Falls 1.65 2235 1.18 1900 3.6 NAB&S XM50 2.45 2700 1.92 2295 NA NAVicta VE50 1.73 2720 1.57 2320 NA NAVicta VEX60 1.95 3300 1.81 2805 NA NANA – Not available

The test speed is specified to be 85% of the speed at which peak power is obtained. It is seen that the peak and test power is relatively low for some engines, and occurs at a low engine speed. This is primarily due to the poor performance of the engine speed governor on these engines. Engine speed governors operate by controlling the carburettor throttle to limit maximum engine speed under conditions of no load. As a load is applied, by cutting grass or by the dynamometer in the testing case, the governor opens the throttle to increase torque to attempt to maintain engine speed.Compared to the Honda and the Briggs and Stratton, the engine speed governors of the other 4-stroke lawnmower engines were in general found to perform poorly. The Honda and Briggs and Stratton engines had governors that opened the throttle rapidly as the engine was loaded, allowing full throttle and maximum torque at high engine speeds, and hence higher power outputs. The other engines generally opened the throttle relatively slowly as the engine speed decreased due to applied load, and therefore full throttle and hence full potential torque was not achieved until much lower rpm. Hence, the power outputs, and the test speeds for the Talon, GMC and Miller-Falls engines in particular, were significantly lower than the Honda and the Briggs and Stratton. It was not noted for these engines whether the throttle was wide open at the test speed.


5.3 Handheld Engine Emission DataThe handheld 2-stroke engine emissions test data is summarised in Figure 5-6and Figure 5-7. Certified engines are identified in the legend by P I for Phase I certified engines and P II for Phase II. The EPA and EU Phase I and II limits are shown on the figure for reference. As discussed in section 4, an estimated tolerance of ±5% must be considered in comparison of the results from this project to the regulated limits. The emissions are not directly comparable to the Phase II limits as DF are required to be applied to the data prior to comparing to the limits (see section 2.2.1).It is seen that all engines except two produce CO emissions below the Phase I limit. Eight engines also produce emissions below the Phase I THC limit, while all are below the Phase I NOx limit. In total, eight engines produce emissions below the Phase I emission limits for all pollutant, including the two that are certified to the EPA Phase II regulation. The Echo which is certified to EU Phase I produced a THC result of 250 g/kW.hr relative to the THC standard of 241 g/kW.hr, however this margin is within the uncertainty limits of the testing conducted for this project. It is not possible to compare the emissions to Phase II limits without the determination of the specific emissions deterioration factors for each engine model tested (refer section 2.2.1). However, review of the 2006 US EPA certification database reveals that of the Phase II certified class IV engines, 91% had CO DF of less than 1.3. Hence, there is a moderate probability that all 12 engines that pass the Phase I CO limit would also pass the Phase II limit. For THC+NOx, only the catalyst Husqvarna recorded raw emissions results lower than the Phase II limit, and hence the DF is irrelevant in comparing the results of the other engines to the Phase II limit.Two engines (the Husqvarna and the Stihl) are certified to the Phase II regulations. The EPA certification database lists DF for the Husqvarna 125L of 1.027 for THC+NOx and 1.14 for CO. Applying these DF to the raw emission results indicates DF adjusted emissions of 50.0 and 286 g/kW.hr for THC+NOxand CO respectively, relative to the Phase II limits of 50.0 and 805 g/kW.hr. The certification emission results listed for this engine on the EPA database are 38 and 98 g/kW.hr respectively for THC+NOx and CO; hence the test results measured in this project represent a significantly poorer performance than the certification engine, particularly for CO. This engine model is fitted with a three way catalytic converter to reduce the exhaust emissions, and although this engine is producing THC emissions much lower than any other engine tested in this project, it is very likely to be operating at a much lower efficiency than that of the certification engine whose results are listed in the certification database. It is also possible that the air-fuel mixture ratio of the test engine is set differently to that of the certification engine and thus also contributing to the results. Further it is noted that the power output of the engine tested in this project was approximately 10% lower than that listed in the certification data, and the cause of this lower power may also be impacting on the emission performance.The Stihl FS45 is certified to the Phase II limits through the emission averaging, banking and trading provisions of the EPA regulations, and hence is not required to meet the Phase II emission limits, rather the manufacturer


declared “family emission level”, or FEL (see section 2.2.2). DF of 1.0 are listed for both CO and THC+NOx in the certification database. The CO emissions from the engine tested at 468 g/kW.hr were significantly lower than the FEL of 536 g/kW.hr, however its THC+NOx emissions of 136 g/kW.hr exceed the FEL of 116 g/kW.hr by 17% (note that the US EPA certification lists a different FEL to the CARB certificate included in Appendix 1). The certification test emission results listed for this engine on the EPA database are 104 and 465 g/kW.hr respectively; hence the test results measured in this project show good agreement for CO, while for THC+NOx, the measured results are 30% higher than certification.The overall performance of the handheld engines relative to the emission standards is shown in Table 5-5.

Table 5-5: Handheld Engine Results Compared to US/European Regulated Emission Standards

No. Tested

Number of Units Below Regulated limits

CO THC NOx THC+NOx OverallPhase I Phase II1 Phase I Phase I Phase II1 Phase I Phase II1

14 12 12 8 14 1 8 11 Direct comparison to Phase II limits is not possible as DF are required. Numbers shown are estimated from review of typical DF of certified engines. Refer to discussion abov e.

Eight of the handheld engines produced emissions below the US/European Phase I emissions limits for all regulated pollutants.Overall, there is a very large variation in the emissions performance between the handheld engines tested. It is seen that for CO, the highest emission result is 19 times the lowest, and for THC+NOx, the highest emission result is 12 times the lowest. Note however that the engine recording the lowest CO result is considered to be operating with an unusually lean air-fuel ratio. As2-stroke engines have a power stroke every engine revolution the heat load in the engine is higher than typical 4-strokes, and hence it is normal for them to operate somewhat rich to limit engine cylinder temperatures. Lean operation would hence result in higher engine heat load and this may impact on engine durability. The variation in emissions performance is likely to be caused by factors such as the air-fuel ratio setting, air-fuel mixture preparation quality (carburettor design), and engine design and manufacturing tolerances. Notwithstanding the above comments regarding mixture strength and durability, there is clearly potential to improve the environmental performance of the worst engines on the Australian market.


1800

1673

1588

1600

1382

1400

1256

1275

Emis

sion

s (g

/kW

.hr) 11

41

1130

1111

1157

1200

1078

1043

1050

939

955

1000

920

880

878

851

857

849

840

854

827

800

723

646

657

611

625

631

637

589

589

574

600

501

473

468

448

439

440

400

288

291

263

251

187

207

224

252

223

164

253

251

234

249

165

250

250

216

212

225

225

123

180

188

165

166

136

200

135

56 48 490

CO THC THC+NOx CO2 BSFC

Emission Pollutant

MTD BC233Ryobi PLT2543YWGMC PHT22Sanli BCS260Star CG330AVicta TTB2226Talon AT33554GMC LTP25SSTalon AB3201Homelite HLT26EDNRyobi PLT3043YW (P I)Echo SRM2305 (P I)Stihl FS45 (P II)Husqvarna 125L (P II)

Phase I & II CO Limit

805 g/kW.hr

Phase I THC Limit 241 g/kW.hr

Phase II THC+NOx Limit, 50 g/kW.hr

Figure 5-6: Handheld Engine Emissions Data Summary, all except NOx


6

5

4.69

Emis

sion

s (g

/kW

.hr) 4

3.19

3

2

1.45

1.29

0.85

0.93 0.71

0.81

0.74

1.01

0.67

0.70

1

0.38

0.39

0NOx

Emission Pollutant

MTD BC233Ryobi PLT2543YWGMC PHT22Sanli BCS260Star CG330AVicta TTB2226Talon AT33554GMC LTP25SSTalon AB3201Homelite HLT26EDNRyobi PLT3043YW (P I)Echo SRM2305 (P I)Stihl FS45 (P II)Husqvarna 125L (P II)

Phase I NOx Limit 5.36 g/kW.hr

Figure 5-7: Handheld Engine Emissions Data Summary, NOx

5.3.1 Comparison of Tested Handheld Engines Emissions Data to Certified Engines

The emissions averaged over the ten uncertified engines tested are compared to the averages of all Phase I (45 engines) and all Phase II (160 engines) Class IV engines listed in the 2006 US EPA certification database in Figure 5-8. The data for the two Phase I and the two Phase II certified engines tested are also shown. Although Phase I engines have separate THC and NOx limits, the data for these engines is combined and shown as THC+NOx in the figure so as to enable comparison to Phase II engines . The NOx contributes negligibly to the THC+NOx, typically being around 1 g/kW.hr. The range of the results in each data set is indicated by the error bars on the graph.It is seen that the average THC+NOx from the uncertified engines tested is significantly higher than the certified engines tested and the averages for the certified engines from the EPA database. The average THC+NOx of the Phase I certified engines on the EPA database is 42% lower than the uncertified engines tested, while the average for the EPA Phase II engines is 78% below the uncertified engines. The error bars also show the highest emitting uncertified engine tested in this project to be around 2.5 times higher than the highest certified engines, while the highest emitting certified engines are seen to be below the average of the uncertified engines tested.It is also seen that while the average THC+NOx of the Phase II engines from the EPA database are around a third of the Phase I engines, it is still higher than the limit of 50 g/kW.hr, and the THC+NOx of the highest emitting Phase II engines is of similar order to the Phase I engines. This is believed to be a result of the averaging and banking allowed for Phase II engines, but not


Phase I engines, which allows Phase II engines to be certified at higher certification levels than the regulated limits.

1200

1000

Emis

sion

s (g

/kW

.hr) 800

600

437412 359400

333284 260

208 166200

9261.4

0

THC+NOx CO

Tested Uncert.

Cert. DBase P I

Tested P I

Cert. DBase P II

Tested P II

Figure 5-8: Comparison of Average Emissions from Tested Handheld Engines to Average Emissions from all Certified Engines in the US EPA Database

There are lesser differences in average CO emissions between the uncertified engines and the certified engines, although the highest emitting uncertified engine tested in this project is seen to be significantly higher in CO than the certified engines. The lesser differences demonstrate the relative leniency of the CO certification limits, and that compliance to the emission limits is primarily a THC issue.The average CO emissions of the two Phase I certified engines tested in this project is 6% higher than the uncertified engines, while the average CO from the Phase II engines tested, the EPA database Phase I and Phase II engines are 12%, 19% and 37% lower respectively than the uncertified engines tested. This analysis indicates that should emission regulations be introduced, significant environmental benefits in terms of THC+NOx reduction are possible. Smaller reductions would be achieved for CO.The magnitude of the improvement in the environmental performance of the entire Australian small handheld engine inventory is dependent on the composition of the small engine market and the statistical relevance of the sample engines tested, and beyond the scope of this study.


5.3.2 Handheld Engine Emissions Data RepeatabilityThe repeatability of the test data combines the repeatability of the measurement equipment and the repeatability of the test engines themselves. The minimum and maximum readings for each pollutant obtained over the test repeats conducted are presented in Table 5-6, as a percentage of the mean result.It is seen there is a large variation in the emissions repeatability of some of the handheld engines compared to others, and in general to the lawnmower data. The very good repeatability exhibited by some handheld engines, and in general by the lawnmower engines, indicates that the much larger variability in the data between tests for some of the handheld engines is due to the performance of these handheld engines themselves.The test to test repeatability ranges from around ±5% for all pollutants for the MTD, Ryobi PLT2543YW, Homelite, Sanli, GMC LTP25SS, Echo and Husqvarna, through to ±35% or more for the two Talons, which showed very large variation in the CO data test to test. The large variations appear likely to be caused by large differences in the air-fuel ratio between tests, and variations in power output possibly associated with this.For the engines with large variability, a single test may not clearly indicate the true emissions performance. For example, for the Talon AT33554, while all three tests produced CO results below the regulated limits, they ranged from 310 to 580 g/kW.hr. For THC, the range was less however only one of the three tests produced a result below the limit.The variability displayed by these engines suggests that multiple tests should be considered for the purposes of certification, with perhaps a requirement that the upper bound of a 95% confidence interval on the mean result must be below the emission limit.

Table 5-6: Repeatability of Handheld Emission data relative to mean result

EngineData Variation Relative to Mean

CO THC NOX CO2 BSFC

Min Max Min Max Min Max Min Max Min MaxMTD BC233 -3% 3% -1% 1% -3% 3% -1% 1% -1% 1%Ryobi PLT2543YW -4% 4% 0% 0% -3% 3% -1% 1% 0% 0%GMC PHT22 -13% 16% -2% 1% -3% 5% -3% 4% -2% 2%Sanli BCS260 -4% 4% -1% 1% 0% 0% -1% 1% -1% 1%Star CG330A -14% 10% -7% 6% -13% 16% -5% 6% -4% 3%Victa TTB2226 -3% 3% -3% 3% -9% 9% -1% 1% -2% 2%Talon AT33554 -34% 23% -9% 8% -16% 22% -7% 10% -8% 6%GMC LTP25SS -2% 2% -6% 4% -1% 1% -1% 2% -3% 3%Talon AB3201 -76% 67% -16% 17% -7% 7% -12% 10% -20% 17%Homelite HLT26EDN -6% 6% -1% 1% -1% 1% -1% 1% -2% 2%Ryobi PLT3043YW (P I) -14% 17% -4% 4% -11% 8% -4% 2% -3% 3%Echo SRM2305 (P I) -4% 4% 0% 0% -4% 4% -2% 2% -1% 1%Stihl FS45 (P II) -9% 4% -4% 3% -8% 10% -2% 2% -3% 2%Husqvarna 125L (P II) -5% 6% -1% 2% -3% 4% -3% 4% -1% 2%


5.3.3 Handheld Engine Power DataThe peak power measured for the handheld engines and corresponding engine speed, are listed in Table 5-7. The manufacturers claimed power is also listed for reference.

Table 5-7: Measured and Claimed Power of Handheld Engines

EnginePeak Power Peak Power

SpeedClaimed Power

Claimed Power Speed

(kW) (RPM) (kW) (RPM)MTD BC233 0.54 7000 0.59 NARyobi PLT2543YW 0.74 7000 0.75 NAGMC PHT22 0.32 5150 NA NASanli BCS260 0.89 7750 0.71 6000Star CG330A 1.04 6400 0.9 6500Victa TTB2226 0.67 6900 NA NATalon AT33554 0.58 6500 0.75 NAGMC LTP25SS 0.64 7250 NA NATalon AB3201 0.45-0.58 7300 NA NAHomelite HLT26EDN 0.59 6500 0.65 NARyobi PLT3043YW 0.69 6750 0.78 -Echo SRM2305 0.53 6750 0.57 7500Stihl FS 45 0.81 7500 0.75 7000Husqvarna 125L 0.69 8000 0.76 8000

Most handheld engines were found to produce peak power relatively close to that claimed. Of those with available claimed power data, eight engines produced less than claimed, but only one of these was significantly lower at -21% below claimed. Three engines, the Star, the Sanli, and the Stihl produced higher power than claimed.


5.4 Comparison of Test Data from Certified Engines Tested to Original Certification Data

The emissions results from the certified engines tested are compared to the certification data for these engines obtained from the US EPA certification database in Table 5-8. As discussed in section 4, an estimated tolerance of ±5% must be considered in comparison of the results from this project to the regulated limits. This offers some insight as to actual emissions performance of certified engines in the Australian market relative to their certification. Certification data could only be sourced for those engines certified to US EPA, and hence the data from the two EU certified engines, the Ryobi PLT-3043YW and the Echo SRM2305 are not compared here.

Table 5-8: Test Data compared to Certification Data

EngineCO THC+NOx

Meas. Cert. Diff Meas. Cert. DiffStihl FS 45 Linetrimmer 468 465 1% 135.9 103.9 +31%Husqvarna 125L Brushcutter1 286 97.7 +292% 50 38.1 +31%Briggs & Stratton XM50 Lawnmower 386 411 -6% 12.5 12.9 -3%

1 – The Husqvarna test data has been adjusted by the deterioration factors listed in the certification database

It should be noted that the test speeds used in this project for the Briggs and Stratton and the Stihl engine varied from those listed in the EPA certification database. The Briggs and Stratton was tested at 3060 rpm in the certification data (implying a peak or rated power at 3600 rpm), whereas peak power was found to be at 2700 rpm for the test engine in this project giving a test speed of 2300 rpm. The Stihl FS45 certification data lists a test speed, corresponding to peak power, of 8300 rpm, relative to the peak power speed of 7500rpm found for the test engine, and the 7000 rpm listed in the specifications in the Stihl handbook. The Husqvarna was tested in this project at the same 8000 rpm as the certification engine.These different test speeds for the Stihl and particularly for the Briggs and Stratton, may have some impact on the emissions results, and hence only an indicative comparison is possible.The US Phase I certified Briggs and Stratton lawnmower engine produced very similar results in this project to the official certification data for this engine, irrespective of the different test speed as discussed above. From this, it appears that the Briggs and Stratton engine tested is performing as might be expected from its certification data.It is seen that for the handheld 2-stroke engines however, there is greater discrepancy between the measured emissions and the certification data. Both of these Phase II certified engines (the Stihl and Husqvarna) produced measured results significantly above the official certification results for THC+NOx (this variation was primarily THC as the NOx emissions were very low), while the CO comparison varied.The results for the Stihl show excellent agreement for the CO results measured in this project to the certification data. The THC+NOx result is 31% higher than the certification data however, which is essentially contributed to


by the THC only. It is not possible to determine the cause of this higher THC result.The Husqvarna data is very much higher for both CO and THC than the official results. This may be due to either an incorrectly set carburettor, and/or the exhaust catalyst fitted to this engine operating below specification.The fact that for the Stihl and the Briggs and Stratton, the CO measured was in excellent agreement with the certification data, while for the Husqvarna the CO was very much greater than the certification data, indicates that there is unlikely to be any systematic error in the measurement procedure that is causing the differences noted in this section.The large differences found for the two handheld engines relative to their original certification indicates that production conformity testing should be considered as a necessary and important component of the implementation of emissions regulations for small petrol engines.


6 ConclusionsThis pilot testing program measured the emissions performance of 8 lawnmower and 14 handheld small garden equipment petrol engines. The engines were tested using a methodology closely based on the procedures specified by the United States Environmental Protection Agency (EPA) and the European Union (EU). The test method in this study included some minor variations from the EPA certification methods. The impact of the variations on the emission results are estimated to be of order ±5%. Hence in comparing test results to EPA and EU regulated limits, this tolerance must be taken into account. However, the methodology used to test all engines in this study was consistent and hence direct comparison of the various engines tested in this study is valid. Durability testing to determine emissions Deterioration Factors required under Phase II regulations was not conducted in this project.The lawnmowers tested included two 2-stroke and six 4-stroke engines, whereas all of the handheld engines were 2-strokes.The testing program has demonstrated that the emissions performance within engine categories varies significantly. The variation in performance is likely to be caused by differences in the engines’ air-fuel ratio settings, the design of the carburettors affecting the quality of the air-fuel mixture preparation, other engine design factors, and manufacturing tolerances.The testing program also indicates that, even though some of the engines tested which are not certified to US or European standards do meet the emissions limits provided under these standards, and taking into account the sample size of this study, significant reductions in air pollutant emissions are likely to be achieved if all new engines were required to meet exhaust emissions limits.LawnmowersLarge variation in the emissions performance of the 4-stroke lawnmower engines was observed, most notably in respect to total hydrocarbon emissions (THC). There was also substantial variation in emissions of carbon monoxide (CO) and oxides of nitrogen (NOx).Despite the variation in CO emissions, all 4-stroke lawnmower engines tested produced CO emissions that were significantly lower than the Phase I limit. Three of the engines tested also produced results below the combined THC+NOx emission limits of EPA and EU Phase I. Of these three engines, only one is actually certified to that standard. It was not possible to compare the test results directly to the Phase II limits2.The 2-stroke lawnmowers tested greatly exceeded the Phase I emissions limits. THC emissions were very high relative to the performance of the 4-stroke engines. Both 2-stroke engines produced THC emissions above 240 g/kW.hr in comparison to the 4-stroke lawnmowers which were all below 25 g/kW.hr. NOx emissions were much lower than for the 4-stroke engines and contributed insignificantly to the combined THC+NOx emissions. CO

2 Emission deterioration factors are required to be applied to emission result prior to comparison to the standard, and these were not determined in this project. See section 2.2.1and 5.2.1 for further discussion.


emissions from the 2-strokes were at least 33% above the Phase I limit in comparison to the 4-stroke lawnmowers, all of which produced results that were significantly below this limit.Comparison of the emission results averaged over all of the seven uncertified lawnmower engines tested in this project to the averages for all of the Phase I and all of the Phase II engines of this class listed in the US EPA certification database indicated much lower emissions for the certified engines. The average CO emissions for the Phase I and Phase II engines listed in the EPA database were 365 and 351 g/kW.hr respectively in comparison to an average of 450 g/kW.hr measured for the uncertified engines. For THC+NOx, the differences are greater with the Phase I and Phase II EPA listed engines averaging 10.6 and 12.2 g/kW.hr respectively compared to the average of 89 g/kW.hr measured for the uncertified engines in this project. The very high THC emissions of the 2-stroke engines in this project contribute greatly to this large difference, however, the EPA listed engines were still lower emitting than the 4-stroke engines tested in this project, which averaged 18.5 g/kW.hr THC+NOx.Hence, based on the comparison of results from the sample of engines tested in this program to engines already certified in the US, if all new lawnmowers were required to meet the limits specified in the US/European regulations, substantial reductions in CO and THC emissions would be expected,. In particular, large CO and THC reductions would result from the regulation of the 2-stroke engines, which emitted far higher than the 4-strokes. On the other hand, the establishment of US emission limits for are not expected to lead to reductions in NOx emissions. No trend in NOx emissions was identified between the 4-stroke engines tested which were above and below the emissions limits for the other pollutants. NOx emissions from the 2-stroke engines were however significantly lower than the US limits.

Handheld enginesThe emissions performance also varied substantially between the 14 handheld engines tested. The particularly large variation in emissions was influenced by 2 engines having significantly higher emissions than the other engines tested. Of the 14 engines tested, two were Phase I certified and two were Phase II certified.Twelve of the engines produced results that were well below the Phase I CO limits, while all were below with the Phase I NOx limit. Eight of these engines also produced results below the Phase I THC emission limits (this includes the two Phase II certified engines).In contrast only one of the two Phase II certified engines produced results below the Phase II combined THC+NOx limit. The other Phase II engine is certified in the US under averaging, banking and trading provisions to a level significantly higher than the Phase II limit. The engine tested in this project produced emissions of a similar order to the US EPA certification data listed for this model.Comparison of the emission results averaged over all of the ten uncertified handheld engines tested in this project to the averages for all of the Phase I


and all of the Phase II engines of this class listed in the US EPA certification database again indicated that certified engines as a class produced much lower emissions than uncertified engines. The average CO emissions for the Phase I and Phase II engines listed in the EPA database were 333 and 260 g/kW.hr respectively in comparison to an average of 412 g/kW.hr measured for the uncertified engines in this project. For THC+NOx, the differences are greater with the Phase I and Phase II EPA listed engines averaging 166 and 61 g/kW.hr respectively compared to the average of 284 g/kW.hr measured for the uncertified engines in this project.Again, if emissions standards were in place for new handheld engines and, taking into account the sample size in this project, reductions in emissions could be expected based on the results from this testing program. This would be particularly the case if handheld engines were required to meet Phase II emissions limits.All of those engines tested which did not meet the Phase I emissions limits failed against the THC limit and therefore THC emissions would likely be reduced if a requirement to meet Phase I standards were in place. Requiring engines to meet the Phase II standards would generate far more substantial reductions in THC. All engines (except those certified to Phase II) emitted THC at levels at least 3 times the combined THC+NOx limit specified under Phase II standards. The NOx emissions from these engines were low and contributed insignificantly to this limit. There was wide variation in the CO emissions from handheld engines tested, although the majority produced results below the Phase I and Phase II limits.


Appendix 1: Engine Certification Labels and Documentation

Figure A1-1: Echo SRM2305SI Certification Plate

Figure A1-2: Briggs and Stratton XM50 Certification Plate


Figure A1-3: Husqvarna 125L Certification Plate

Figure A1-4: Ryobi PLT3043YW Certification Plate

Figure A1-5: Stihl FS45 Certification Plate


Figure A1-6: Stihl FS45 CARB Certification


Figure A1-7: Husqvarna 125L CARB Certification

Appendix 2: Complete Test Data (Note idle emissions data mode 6 lawnmowers, mode 2 handhelds, is in g/hr, other modes in g/kW.hr) Honda GCV 160 4-stroke Lawnmower Data Test 1232 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2641 8.07 2.23 342 4.54 2.60 700 395 2 0.2 2631 6.03 1.66 232 4.13 7.37 840 384 3 0.29 2608 4.03 1.10 326 5.69 3.89 916 456 4 0.3 2617 1.91 0.52 765 15.9 0.83 1024 717 5 0.07 2595 0.77 0.21 627 17.9 1.94 2691 1177 6 0.05 1587 0.39 0.07 151 6.99 0.12 253 162

Weighted Result 376 7.02 4.26 900 477 X` Test 1233 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2637 8.01 2.21 388 5.12 1.83 666 407 2 0.2 2618 6.05 1.66 239 4.19 7.26 841 388 3 0.29 2632 4.05 1.12 326 5.09 3.98 925 458 4 0.3 2640 1.92 0.53 735 15.2 0.90 1034 705 5 0.07 2647 0.75 0.21 1917 74.8 1.05 2125 1695 6 0.05 1617 0.40 0.07 160 7.33 0.12 258 168

Weighted Result 402 7.70 4.09 891 488

Difference Test 2 vs Test 1 6% 9% -4% -1% 2%

Average 389 5.98 452.10 449 483

Diesel Test Australia Emission testing, research and project management 43

Sanli OHV400 4-stroke Lawnmower Data Test 1239 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2515 5.95 1.57 456 6.70 1.86 752 469 2 0.2 2529 4.51 1.19 205 5.08 8.98 992 419 3 0.29 2517 2.96 0.78 137 5.54 6.59 1177 444 4 0.3 2486 1.46 0.38 233 9.78 2.05 1739 674 5 0.07 2497 0.64 0.17 519 20.8 2.06 3256 1304 6 0.05 1953 0.72 0.15 64.5 3.37 0.26 440 174

Weighted Result 244 6.68 5.64 1174 497

Test 1240 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2512 6.16 1.62 443 6.47 1.80 726 455 2 0.2 2527 4.55 1.20 198 5.33 9.46 976 411 3 0.29 2538 3.08 0.82 117 5.61 7.43 1140 423 4 0.3 2521 1.57 0.41 202 8.84 2.19 1639 626 5 0.07 2494 0.72 0.19 492 23.2 1.88 2926 1189 6 0.05 1922 0.59 0.12 91.6 3.90 0.18 373 167

Weighted Result 229 6.71 6.01 1136 479

Difference Test 2 vs Test 1 -6% 0% 7% -3% -4%

Average 237 6.70 5.82 1155 488


Talon Surefire 145 4-stroke Lawnmower Data Test 1246 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2041 4.79 1.02 271 12.1 8.85 1130 502 2 0.2 2069 3.66 0.79 387 14.0 4.41 1096 551 3 0.29 2079 2.47 0.54 529 16.0 2.14 1185 651 4 0.3 2060 1.27 0.27 283 19.7 2.67 2076 814 5 0.07 2047 0.74 0.16 411 35.9 2.29 3181 1242 6 0.05 1950 0.53 0.11 56.2 5.76 0.29 465 180

Weighted Result 395 16.1 4.17 1369 643


1 0.09 2041 5.20 1.11 255 11.6 7.69 1047 468 2 0.2 2052 3.92 0.84 366 13.6 4.31 1067 531 3 0.29 2028 2.66 0.57 473 15.5 2.28 1167 618 4 0.3 2058 1.29 0.28 262 20.1 2.48 2059 799 5 0.07 2032 0.58 0.12 416 42.6 2.52 3981 1504 6 0.05 1935 0.56 0.11 42.8 5.23 0.29 479 178

Weighted Result 363 15.7 3.98 1332 615

Difference Test 2 vs Test 1 -8% -3% -4% -3% -4%

Average 379 15.9 4.08 1350 629


GMC ECO 4 4-stroke Lawnmower Data Test 1276 - Tested using "Choke" to control power/speed Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2418 5.25 1.33 505 17.9 1.51 714 493 2 0.2 2510 3.97 1.04 1121 87.0 0.15 664 852 3 0.29 2298 2.63 0.63 1668 289 0.26 954 1416 4 0.3 2355 1.28 0.32 2863 1273 0.85 1777 3252 5 0.07 2368 0.77 0.19 4211 2755 1.83 2770 5715 6 0.05 2356 0.92 0.23 861 489 0.32 582 1099

Weighted Result 1539 405 0.60 1004 1484


1 0.09 2524 4.57 1.21 254 9.3 4.71 943 432 2 0.2 2671 3.32 0.93 151 10.3 7.81 1151 448 3 0.29 2781 2.18 0.63 280 15.7 3.71 1372 587 4 0.3 2854 1.07 0.32 135 16.8 3.48 2488 868 5 0.07 2859 0.69 0.21 244 22.6 3.28 3432 1226 6 0.05 2856 0.69 0.21 52.0 4.76 0.68 709 254

Weighted Result 211 13.3 5.11 1490 587


1 0.09 2528 4.41 1.17 273 9.38 4.60 940 441 2 0.2 2698 2.99 0.85 526 66.1 1.44 1016 647 3 0.29 2776 2.05 0.60 325 26.4 3.53 1537 672 4 0.3 2874 1.01 0.31 190 24.7 3.52 2485 902 5 0.07 2895 0.63 0.19 236 25.2 3.73 3680 1302 6 0.05 2886 0.61 0.19 42.6 4.90 0.73 693 245

Weighted Result 350 34.9 3.11 1510 684


1 0.09 2417 5.14 1.30 526 23.8 1.60 744 519 2 0.2 3147 3.84 1.26 226 15.4 4.63 1068 464 3 0.29 3250 2.40 0.82 209 23.5 3.81 1398 568 4 0.3 3308 1.70 0.59 202 26.0 2.99 1763 682 5 0.07 3300 1.70 0.59 147 21.5 3.46 1800 662 6 0.05 3309 1.65 0.57 120 12.3 1.65 1022 394

Weighted Result 253 21.5 3.53 1318 563

Difference - Range/Average Tests 2-4 51% 93% 51% 13% 20%

Average Tests 2-4 271 23.2 3.92 1439 611


Miller Falls S510T Easymo 4-stroke Lawnmower Data Test 1262 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 1898 5.94 1.18 358 8.00 4.08 792 435 2 0.2 1939 4.44 0.90 203 7.70 8.91 1031 433 3 0.29 1884 2.93 0.58 366 11.40 2.94 1114 544 4 0.3 1937 1.48 0.30 905 28.5 1.23 1536 961 5 0.07 1887 0.67 0.13 2088 116.3 1.26 2765 2022 6 0.05 1297 0.56 0.08 224 24.8 0.06 270 221

Weighted Result 445 16.2 4.77 1137 595


1 0.09 1899 5.93 1.18 350 7.81 4.37 804 435 2 0.2 1923 4.42 0.89 208 7.42 9.26 1043 439 3 0.29 1914 3.10 0.62 339 10.5 3.95 1125 533 4 0.3 1901 1.45 0.29 918 30.7 1.28 1573 981 5 0.07 1853 0.63 0.12 2329 139.2 1.29 2898 2206 6 0.05 1269 0.53 0.07 250 29.1 0.05 238 228

Weighted Result 439 16.6 5.24 1149 596

Difference Test 2 vs Test 1 -1% 3% 10% 1% 0%

Average 442 16.4 5.01 1143 596


Briggs and Stratton XM50 4-stroke Lawnmower Data Test 1259 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2295 7.90 1.90 404 5.68 2.47 814 462 2 0.2 2302 5.91 1.42 321 5.68 4.45 969 470 3 0.29 2302 3.91 0.94 329 7.41 2.84 1125 525 4 0.3 2234 1.94 0.45 560 20.5 1.13 1514 775 5 0.07 2276 0.85 0.20 201 39.7 2.58 3965 1389 6 0.05 2018 0.65 0.14 16.5 9.65 0.47 705 240

Weighted Result 373 9.53 3.02 1151 557


1 0.09 2298 8.06 1.94 401 5.64 2.56 820 462 2 0.2 2324 5.98 1.46 370 6.32 3.55 937 485 3 0.29 2252 4.12 0.97 333 7.49 2.90 1106 521 4 0.3 2304 1.97 0.48 600 20.1 1.30 1572 813 5 0.07 2307 0.92 0.22 338 28.2 2.45 3613 1335 6 0.05 1972 0.51 0.11 15.4 11.5 0.43 681 234

Weighted Result 398 9.68 2.79 1144 568


Average 386 9.61 2.91 1147 562


Victa VE50 2-stroke Lawnmower Data Test 1266 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2309 6.50 1.57 492 183 0.55 784 851 2 0.2 2351 4.85 1.19 523 158 0.42 792 847 3 0.29 2315 3.27 0.79 674 225 0.33 858 1032 4 0.3 2311 1.73 0.42 1602 898 0.50 1276 2627 5 0.07 2413 0.96 0.24 2985 2613 1.01 2054 4874 6 0.05 2467 0.77 0.20 3568 3359 1.24 2542 5875

Weighted Result 835 401 0.45 941 1352


1 0.09 2318 6.46 1.57 415 175 0.55 790 629 2 0.2 2318 4.90 1.19 434 142 0.41 810 613 3 0.29 2368 3.16 0.78 641 199 0.28 914 805 4 0.3 2241 1.66 0.39 1313 580 0.31 1472 1695 5 0.07 2277 0.73 0.17 2553 1550 0.57 2729 3675 6 0.05 1476 0.54 0.08 331 276 0.09 320 541

Weighted Result 688 276 0.39 991 929

Difference Test 2 vs Test 1 -21% -45% -17% 5% -46%


1 0.09 2313 6.51 1.58 458 183 0.51 789 658 2 0.2 2320 4.78 1.16 553 161 0.32 790 684 3 0.29 2325 3.17 0.77 660 248 0.33 846 842 4 0.3 2311 1.62 0.39 1236 554 0.47 1415 1613 5 0.07 2281 0.74 0.18 2343 1509 1.05 2504 3459 6 0.05 1486 0.69 0.11 331 285 0.17 323 551

Weighted Result 726 296 0.41 953 956

Difference Test 3 vs Test 2 5% 7% 4% -4% 3%

Average Test 2-3 707 286 0.40 972 943


Victa VEX60 2-stroke Lawnmower Data Test 1271 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.09 2808 6.14 1.81 413 164 0.66 818 627 2 0.2 2861 4.60 1.38 591 165 0.42 819 716 3 0.29 2826 3.02 0.89 708 194 0.35 928 837 4 0.3 2805 1.47 0.43 1133 385 0.34 1393 1386 5 0.07 2844 0.85 0.25 1708 761 0.52 1993 2236 6 0.05 2807 0.90 0.26 470 215 0.14 518 611

Weighted Result 716 229 0.43 981 893


1 0.09 2808 6.18 1.82 445 165 0.61 783 632 2 0.2 2858 4.72 1.41 615 172 0.39 789 726 3 0.29 2759 3.08 0.89 708 231 0.39 911 869 4 0.3 2808 1.62 0.48 1072 375 0.39 1275 1307 5 0.07 2802 0.90 0.26 1667 786 0.56 1860 2199 6 0.05 2160 0.70 0.16 479 379 0.23 448 758

Weighted Result 730 255 0.45 945 914

Difference Test 2 vs Test 1 2% 10% 2% -4% 2%

Average 723 242 0.44 963 903


MTD BC233 2-stroke Brushcutter Data Test 1282 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 7003 0.74 0.546 344 216 0.966 1211 768 2 0.1 0.000 53.4 58.1 0.050 105 118

Weighted Result 355 228 0.98 1233 792


1 0.9 7003 0.74 0.540 476 235 0.867 1132 827 2 0.1 0.000 55.3 61.9 0.051 100 121

Weighted Result 488 247 0.88 1152 852



1 0.9 7003 0.74 0.539 503 239 0.817 1108 837 2 0.1 0.000 53.9 59.3 0.042 105 119

Weighted Result 514 251 0.83 1130 862


Average Test 2-3 501 249 0.85 1141 857


Ryobi PLT2543YW 2-Stoke Linetrimmer Data Test 1320 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 7005 1.00 0.736 213 178 1.249 1017 604 2 0.1 4951 0.11 0.057 84.9 65.0 0.070 180 164

Weighted Result 224 186 1.25 1036 624


1 0.9 7005 1.00 0.733 197 179 1.328 1045 606 2 0.1 4918 0.11 0.057 85.7 65.6 0.076 185 166

Weighted Result 208 188 1.33 1064 626

Difference Test 2 vs Test 1 7% -1% -6% -3% 0%

Average 216 187 1.29 1050 625


GMC PHT22 2-stroke Hedgetrimmer Data Test 1315 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 5151 0.56 0.303 105 275 3.10 1613 836 2 0.1 41.4 41.9 0.033 104 95.1

Weighted Result 120 290 3.11 1651 870


1 0.9 5152 0.61 0.331 129 279 3.09 1503 816 2 0.1 0.000 38.1 38.2 0.038 110 91.8

Weighted Result 142 291 3.10 1540 847

Difference Test 2 vs Test 1 18% 0% 0% -7% -3%


1 0.9 5152 0.62 0.335 96.0 270 3.35 1534 801 2 0.1 0.000 31.3 36.3 0.039 120 89.8

Weighted Result 106 282 3.36 1574 831

Difference Test 3 vs Test 2 -25% -3% 8% 2% -2%

Average Tests 1-3 123 288 3.19 1588 849


Sanli BCS260 2-stroke Linetrimmer Data Test 1303 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 7760 1.10 0.896 57.4 198 4.67 1223 612 2 0.1 0.000 5.23 60.6 0.063 162 114

Weighted Result 58.1 205 4.67 1243 626


1 0.9 7759 1.09 0.888 53.6 202 4.69 1252 623 2 0.1 0.000 3.96 58.9 0.081 140 105

Weighted Result 54.1 209 4.70 1269 636

Difference Test 2 vs Test 1 7% -2% -1% -2% -2%

Average 56.1 207 4.69 1256 631


Star Products CG330A 2-stroke Linetrimmer Data Test 1294 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 6406 1.57 1.053 492 233 0.803 820 736 2 0.1 0.000 23.4 40.7 0.041 118 89.7

Weighted Result 495 238 0.81 833 745


1 0.9 6406 1.57 1.053 463 222 0.891 857 722 2 0.1 0.000 9.70 35.6 0.045 134 82.6

Weighted Result 464 226 0.90 871 730



1 0.9 6409 1.51 1.012 382 204 1.07 923 684 2 0.1 0.000 27.3 41.8 0.053 120 93.1

Weighted Result 385 209 1.08 936 694


Average Tests 1-3 448 224 0.93 880 723


Victa TTB2226 2-stroke Linetrimmer Data Test 1300 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 6903 0.93 0.674 812 390 0.762 931 1086 2 0.1 0.000 101 218 0.088 89.9 296

Weighted Result 829 426 0.78 946 1135


1 0.9 6904 0.92 0.665 857 417 0.632 917 1130 2 0.1 101 213 0.077 93.4 293

Weighted Result 874 452 0.64 932 1179


Average 851 439 0.71 939 1157


Talon AT33554 2-stroke Linetrimmer Data Test 1310 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 6506 0.84 0.574 569 260 0.670 982 852 2 0.1 59.5 63.6 0.036 100 125

Weighted Result 581 273 0.68 1002 876


1 0.9 6506 0.86 0.588 299 217 0.984 1167 733 2 0.1 60.2 61.7 0.032 105 125

Weighted Result 310 229 0.99 1187 757



1 0.9 6507 0.86 0.588 517 244 0.752 1024 822 2 0.1 60.6 63.0 0.039 109 127

Weighted Result 528 256 0.76 1044 847


Average Tests 1-3 473 252 0.81 1078 827


GMC LTP25SS 2-stroke Linetrimmer Data Test 1339 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 7254 0.83 0.629 1060 610 0.373 870 1409 2 0.1 3164 0.06 0.019 35.2 39.2 0.048 152 105

Weighted Result 1063 614 0.38 894 1423


1 0.9 7253 0.86 0.655 1019 548 0.374 852 1322 2 0.1 3193 0.06 0.020 36.8 39.2 0.045 150 105

Weighted Result 1022 553 0.38 875 1335

Difference Test 2 vs Test 1 4% 11% 0% 2% 7%


1 0.9 7253 0.84 0.639 1041 594 0.379 845 1377 2 0.1 3214 0.06 0.022 35.8 38.2 0.044 144 101

Weighted Result 1043 599 0.39 867 1389

Difference Test 3 vs Test 2 -2% -8% -1% 1% -4%

Average Tests 1-3 1043 589 0.38 878 1382


Talon AB3201 2-stroke Blower Data Test 1343 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 7304 0.76 0.579 13.0 153 1.33 1457 618 2 0.1 3041 0.05 0.017 156 188 0.082 144 311

Weighted Result 42.7 188 1.34 1480 676


1 0.9 7304 0.58 0.447 266 215 1.54 1804 915 2 0.1 2510 0.04 0.010 141 184 0.064 135 297

Weighted Result 300 260 1.55 1833 986

Difference Test 2 vs Test 1 -86% -28% -13% -19% -31%


1 0.9 7304 0.67 0.510 163 184 1.45 1681 795 2 0.1 3726 0.07 0.028 162 177 0.061 160 307

Weighted Result 197 221 1.45 1706 857


Average Tests 1-3 180 223 1.45 1673 840


Homelite HLT26EDN 2-stroke Linetrimmer Data Test 1349 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 6503 0.87 0.589 227 141 0.727 1124 608 2 0.1 2861 0.05 0.014 110 135 0.066 87.0 217

Weighted Result 247 166 0.74 1137 647


1 0.9 6502 0.88 0.598 201 137 0.742 1110 587 2 0.1 2902 0.05 0.014 111 141 0.049 87.1 223

Weighted Result 221 163 0.75 1124 626

Difference Test 2 vs Test 1 12% 2% -2% 1% 3%

Average 234 164 0.74 1130 637


Ryobi PLT3043YW 2-stroke Linetrimmer Data Test 1325 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 6752 0.98 0.695 296 162 0.895 1054 641 2 0.1 3373 0.06 0.022 85.7 64.7 0.037 134 149

Weighted Result 309 171 0.90 1072 662


1 0.9 6754 0.97 0.689 213 149 1.08 1105 603 2 0.1 3386 0.05 0.019 85.3 63.6 0.052 147 152

Weighted Result 226 158 1.08 1125 625



1 0.9 6754 0.95 0.675 241 154 1.03 1118 626 2 0.1 3331 0.05 0.018 84.7 65.1 0.050 136 150

Weighted Result 254 165 1.04 1137 649

Difference Test 3 vs Test 2 -11% -4% 4% -1% -4%

Average Tests 1-3 263 165 1.01 1111 646


Echo SRM2305SI 2-stroke Brushcutter Data Test 1289 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.9 6754 0.75 0.534 624 236 0.630 919 835 2 0.1 0.000 53.8 64.9 0.050 90.3 120

Weighted Result 636 250 0.64 938 860


1 0.9 6754 0.74 0.524 574 237 0.685 952 822 2 0.1 52.4 63.2 0.052 95.1 119

Weighted Result 585 251 0.70 972 847


Average 611 250 0.67 955 854


Stihl FS45 2-stroke Linetrimmer Data Test 1354 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.85 7504 1.03 0.812 481 132 0.674 890 651 2 0.15 33.8 34.0 0.042 128 91.0

Weighted Result 488 139 0.68 918 670


1 0.85 7504 1.04 0.815 421 122 0.767 911 617 2 0.15 32.4 34.0 0.029 126 89.9

Weighted Result 428 129 0.77 939 637



1 0.85 7504 1.03 0.812 482 130 0.640 874 644 2 0.15 30.4 33.5 0.036 132 90.2

Weighted Result 488 137 0.65 903 663


Average Tests 1-3 468 135 0.70 920 657


Husqvarna 125L 2-stroke Brushcutter Data Test 1330 Mode Weight Speed Torque Power CO THC NOx CO2 BSFC

1 0.85 8001 0.84 0.701 243 45.8 0.381 1211 548 2 0.15 0.000 21.7 7.82 0.015 179 74.9

Weighted Result 248 47.7 0.38 1256 567


1 0.85 8004 0.80 0.672 231 45.8 0.403 1283 565 2 0.15 0.000 26.1 8.07 0.011 178 77.0

Weighted Result 238 47.9 0.41 1330 585

Difference Test 2 vs Test 1 4% 0% -5% -6% -3%


1 0.85 8004 0.83 0.696 260 47.1 0.370 1194 552 2 0.15 25.9 8.29 0.026 178 77.1

Weighted Result 266 49.2 0.38 1239 572


Average Tests 1-3 251 48.3 0.39 1275 574


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