THIS IS A MANUAL PRODUCED BY JENSALES INC. WITHOUT THE AUTHORIZATION OF TECUMSEH OR IT’S SUCCESSORS. TECUMSEH AND IT’S SUCCESSORS

ARE NOT RESPONSIBLE FOR THE QUALITY OR ACCURACY OF THIS MANUAL.

TRADE MARKS AND TRADE NAMES CONTAINED AND USED HEREIN ARE THOSE OF OTHERS, AND ARE USED HERE IN A DESCRIPTIVE SENSE TO REFER TO THE PRODUCTS OF OTHERS.

Service Manual

Serv

ice

Man

ual

2-7 HP Engines

TE-S-2-7HP

TECU'MSEH

LAUSON 4-STROKE CYCLE ENGINE

MECHANIC'S HANDBOOK (LIGHT AND MEDIUM FRAMES)

PRICE: FIFTY CENTS

GENERAL

INFORMATION

AIR CLEANERS, CARBURETORS, GOVERNORS AND LINKAGES

REWIND AND WIND-UP STARTERS

ALTERNATORS, CHARGERS, AND ELECTRIC STARTERS

IGNITION

CYLINDER BLOCK AND POWER TRAIN

TROUBLE­SHOOTING

TABLE OF SPECIFICATIONS

TECUMSEH PRODUCTS COMPANY PARTS DEPOT DIVISION GRAFTON, WISCONSIN 53024

LITHO IN U.S.A. / FORM NO. 692509

.. -STROKe ",,, .. Li ENGI"-':

~LE C

~RT I. tAL IN

SECTION 1. INTRODUCTION A. General . . . . . B. Types of Engines . . . • C. Use of This Manual . • D. Information Not Covered Herein.

SECTION 2. ENGINE IDENTIFICATION A. Lauson 4-Cycle Engines . . . B. Shortblocks ....•••. C. "Light Frame" Designation •• D. "Medium Frame" Designation

SECTION 3. ENGINE CARE A. Maintenance Rules B. Fuels and Lubricants C. General Comments D. Engine Tune-Up Procedure.

SECTION 4. 4-CYCLE ENGINE THEORY

Page

1-1-1 1-1-1 1-1-1 1-1-1

1-2-1 1-2-1 1-2-1 1-2-1

1-3-1 1-3-1 1-3-2 1-3-2

A. 4-Cycle Theory . • • . . . •• 1-4-1 B. Pre-Overhaul Check of 4-Cycle

Engines •••••. , . • 1-4-2 C. Points to Check for Engine

Power • • . . . . . • • • 1-4-3 D. Points to Check for Engine Oil

Control ...•...... 1-4-4

PART II. AIR CLEANERS, RBURETORS, GOVERNORS

ANn LlNK.At;E

SECTION 1. AIR CLEANERS A. Air Cleaner Service . . B. Polyurethane Type Air Cleaner C. Paper Type Element. . • . D. Oil Bath Air Cleaner E. Treated Paper Element Type F. Kleen-Aire® System

SECTION 2. CARBURETORS -GENERAL INFORMATION

2-1-1 2-1-1 2-1-1 2-1-2 2-1-2 2-1-3

A. General . • . . . . . . • 2-2-1 B, Carburetor Operation • • ., 2-2-1 C. Carburetor Removal & Dis-

assembly. . . . . • , . . .• 2-2-3 D. Inspection of Carburetor Parts 2-2-4

Litho in U.S.A.

)NTEr

E. Carburetor Reassembly & Installation . . • • . . .

F. Inlet Needle Damper Spring. G. Welch Plug Service . . . . H. Fuel Primers. . . . . . . 1. Fuel Mixture Adjustments . J. Final Carburetor Adjustments K. Carburetor Reinstallation . .

Page

2-2-4 2-2-5 2-2-5 2-2-6 2-2-6 2-2-7 2-2-7

SECTION 3. FLOAT FEED CARBURETORS -SPECIFIC MODELS

A. Float Feed Carburetors • • . . B. Tecumseh Identification • . . . C. Disassembly and Service Instruc-

tions D. Throttle . . . . . . E. Choke . • . . . . . . • • F. Idle Adjusting Screw. • • . G. High Speed Adjusting Screw H. Fuel Bowl Retaining Nut 1. Fuel Bowl . • • . . J. Float .. • • . . . K. Inlet Needle and Seat L. Fuel Inlet Fitting . . M. Carburetor Body N. Resilient Tip Needle Service O. Servicing the Viton Seat . . P. Viton Seat Replacement . •

SECTION 4. TECUMSEH AUTOMAGIC (Non-Adjustable Float Feed) CARBURETOR - (Includes Internal Vented Carburetors)

2-3-1 2-3-1

2-3-1 2-3-3 2-3-3 2-3-3 2-3-3 2-3-4 2-3-4 2-3-5 2-3-6 2-3-6 2-3-7 2-3-8 2-'3-8 2-3-8

A. Operation 2-4-1 B. Adjustment. • . . . . . .. 2-4-2 C. Cleaning . . . . • . . . . .. 2- :-2 D. Internally Vented Carburetors 2-4-2

SECTION 5. WALBRO AND TILLOTSON FLOAT FEED CARBURETORS

A. Walbro Float Feed Carburetors. 2-5-1 B. Tillotson E Float Feed Type

Carburetor Adjustments . . 2-5-2 C. Walbro Carburetor #631635 2-5-3

SECTION 6. DIAPHRAGM (Pressure Differential) CARBURETORS

A. Diaphragm (Pressure Differential) Carburetors . . . . . . .. 2 -6-1

B. Diaphragm Carburetor Service. 2-6-1

i

4-STROK E CYCLE ENGINE

TABLE OF CONTENTS (Continued) Page

SECTION 7 . CRAFTSMAN FUEL SYSTEMS A. Fuel Tank Mounted Carburetor 2-7-1 B . New Carburetor Compared to

Early Model . . . . . . . C . Carburetor - Service Checks D. Disassembly and Service . E. Reassembly .... F. Adjustments . . . . . . G. Camshaft Installation • H. Craftsman Float Type Carburetor 1. Craftsman Fuel System With

2-7-2 2-7-3 2- 7-3 2-7-5 2-7 - 6 2-7-6 2-7 -7

Float Bowl Reservoir & Variable Governor Adjustment . ... . 2-7-10

SECTION 8. GOVERNORS A. Air Vane Governors . . . . .. 2-8-1 B. Mechanical Governor Installation

and Adjustment . . . . . . .. 2-8-3 C. Installing Internal Governor Gear

Shaft in Mounting Flange . . .. 2- 8-4

SECTION 9. CARBURETOR CONTROL LINKAGE

A. General . • . . . . . • • . B . Operation ..... •... • C. Control Lever & Panel Adjust-

ment. . . . . • . . . D. Craftsman Fuel System

Governor Adjustment • E. Automagic Carburetor Control

Panel • . . . . • . . . . . F. Choke Override Control Panel G. Mini-Bike Speed Control

Assemblies . . . . . . . . .

PART III. REWIND AND WIND-UP STARTERS

SECTION 1. REWIND (Recoil) STARTER SERVICE

A. Operation. . . . . . . • . . B. Rewind Starter - Friction Shoe

Type . . . . . . . . . . C. Rewind Starter - Dog Type

(590405) . . . . . . . . . . D. Rewind Starter - Dog Type . . E. Rewind Starter - Dog Type (Ser .

No. 590408 and Variations) . . . F. The Side Mounted Starter (Present

Type) . • . . . . . . . . . . G. Side Mount Starter (Early Type) . H. 8 H.P . Engine Rewind Starter

590479 •.• •. 1. Rewind Starter . .

J . Sno - Proof Starters

2-9-1 2-9-1

2-9- 6

2-9-6

2- 9-7 2-9-7

2-9-8

3-1-1

3-1-1

3-1-2 3-1-2

3-1- 3

3-1-4 3-1-6

3- 1-6 3- 1-7 3- 1-7

SECTION 2. WIND-UP STARTERS A. Operation . . . . . . . . . B. Replacing Rewind Starter with

Ratchet Starter on Lauson Engines ... . . .. . .

C. Wind - Up Starters . . . . . D. Ratchet Starter Disassembly

and Reassembly ..... E . Self Starter Disassembly and

Reassembly . . . . . . . . F. Keylock Starters . . . . . G. Sure Lock Starter Disassembly

and Reassembly. . • . . H. Sure Start Starter . . . . 1. Power Spring Replacement

PART IV. ALTERNATORS, CHARGERS, AN 0

ELECTRIC STARTERS

SECTION 1. GENERAL A. Using the Starter B. Troubleshooting. C. Cold Weather Starting D. Electric Starter Service E . Electrical Starter System

Inspection . . . • . . . F. Electrical Starter System Testing G. Lubrication. . . . . . . . .

SECTION 2. 12 VOLT DC ELECTRIC

A.

B.

C. D. E .

F.

G.

H. 1. J .

STARTERS Service Procedures - 12 Volt DC Electric Starter (29964-29965-32468 and 32468A) .... . . Service Procedures - 12 Volt DC Electric Starter (32468B and 33202) . . . . . . . . . . . . Test . . . . . . . . . . . . . 12 Volt Electric Starter (32721) 12 Volt Electric Starter (32806) for Light Frame Vertical Crankshaft Engines . . . . . Nickel - Cadmium Battery Pack General Comments . . . . . Starting the Engine the First Time (Or at the Beginning of a New Season) . . . . . . . . Battery Storage . . . . . . . Service . . . . . . . . . . . 12 Volt Saf-T-Key Battery Pack Testing Procedure . . . . . . .

Page

3-2-1

3-2-1 3-2-2

3-2 -2

3-2 - 3 3-2-3

3-2-4 3-2 -5 3-2-6

4-1-1 4-1-2 4-1 -2 4-1 -2

4-1 - 3 4- 1- 3 4-1-3

4-2-1

4-2 -2 4-2 -2 4-2 - 3

4-2-4

4-2-4

4-2-5 4-2 - 5 4-2-5

4-2-6

ii Litho in U. S. A.

" ,

4-STROKE CYCLE ENGINE

TABLE OF CONTENTS (Continued)

K. Ni-Cad Battery Disassembly and Parts Replacement Procedures

Page

(New Type 32635A Only) , . .. 4-2-8 L. Assembly Procedures • . . .. 4-2-9

SECTION 3. 110 VOLT AC-DC ELECTRIC STARTERS

A. Rectifier Assembly Inspection (110 V Starters Only) • • • •

B. Rectifier Assembly Testing (110 V Starters Only)

C. Testing Cranking Motor . . D. Repair of 110 Volt AC-DC

Starter Nos. 30867 and 30867A . K Rectifier (110 Volt Systems Only) F. Field Replacement of Early

Rectifier with New Molded Assembly ...••...

G. Service Procedure - 110 Volt AC-DC Starter #32386

H. 11 0 V oIt Starter. . . .

SECTION 4. ALTERNATORS A. Operation . . . . . . B. Ignition Coil. . . . . C. Types of Alternator Systems. D. Circuits Containing Solenoids E. Alternating Current Lighting

Circuits F. T ting ~ . . D • • • ~ •

.- ,.u~T V. IGNIT._ ...

SECTION 1. IGNITION COMPONENTS AND OPERATION

A. Magneto Ignition B. Stator Assembly C. Contact Points . D. Condenser • • • • E. The Ignition Coil F. How Tecumseh Magneto Ignition

Works • . . • • . . . • • •

SECTION 2. IGNITION SERVICE A. Checking Operation of Ignition

System •••..•.•. B. Spark Plug Service • . • • C. Conditions Causing Frequent

Spark Plug Fouling D. Magneto Adjustment • . . .

Litho in U.S.A. 3/72

4-3-1

4-3-1 4-3-2

4-3-3 4-3-4

4-3-6

4-3-7 4-3-8

4-4-1 4-4-1 4-4-1 4-4-2

4-4-3 4-4-4

5-1-1 5-1-1 5-1-1 5-1-1 5-1-2

5-1-3

5-2-1 5-2-1

5-2-1 5-2-2

E. Repl 0 Breaker Points . . . •

F. Magneto Removal . • • • . G. Checking Magr.~.j.~ Parts . . H. Reassembly and Installation of

Magneto . . . . • • . .

SECTION 3. IGNITION TIMING PROCEDURE ...

SECTION 4. SOLID STATE IGNITION A. General • • • • . . . . . . B. Operation .••...... C. Light & Medium Frame Engine

Solid State Ig-nition System . . •

PART )ER BLOCK TRAIN

SECTION L GENERAL - INDEX -ACCESSORIES

A. Explanation ..... B. Accessories • • • • . C, Spark Arrester Mufflers

SECTION 2. PISTON, RING, PIN, CONNECTING ROD AND CRANKSHAFT SERVICE

A. Cra-'-,haft . . . • • . . • B. Tirr. J Marks .•.•.. C. LAV40 and HS40 Crankshafts D. Piston . . . • . . . . E. Rings . . . . . . . • • . F. Connecting Rods .•... G. LAV40, HS40, V70, V80, H70

and H80 Connecting Rods

SECTION 3. CAMSHAFT, VALVES, SPRINGS, MECHANICAL FUEL PUMP AND OIL PUMP SERVICE

A. Camshaft, • . . • . . . . B. Valve Springs. . • . . • • C. Valve Lifters (4 H.P, Light

Frame Models) . , • . . . . D. Valve Grinding & Replacement E. Mechanical Fuel Pump, . . . F. Crankcase Impulse Fuel Pump

#32959 • • • • • . . . , . . G, Barrel and Plunger Oil Pump

System. • • • • • , . , . . H. Spray Mist Lubrication 1. Barrel Type Oil Pump Service • J. Splash Type Lubrication • . .

Page

5~2-3

5~2~3 h c) A

5-2-5

5-3-1

5-4-1 5-4-1

5-4-2

6-1-1 6-1-1 6-1-2

6-2-1 6-2-1 6-2-2 6-2-2 6-2-3 6-2-4

6-2-5

6-3-2 6-3-2 6-3-4

6-3-5

6-3-7 6-3-7 6-3-8 6-3-9

iii

4-STROKE CYCLE ENGINE

TABLE OF CONTENTS (Continued) Page

K. Gear Type Oil Pump System & Service ..... . . . 6-3 -10

SECTION 4. CYLINDER, HEAD, VALVE SEATS AND BREATHER

A. Cylinder and Head Service B . Reboring Cylinder C. Reboring Valve Guides .. D. Regrinding Valve Seats E . Crankcase Breather Service F. Crankcase Breather . . . . G. Engines with Integral Breather

System ........ . .

6-4-1 6-4-1 6-4-2 6-4- 2 6-4 -3 6-4-3

6-4-4

SECTION 5. MOUNTING FLANGE (Vertical) AND CYLINDER COVER (Horizontal) SERVICE

iv

A. Mounting Flange Removal (Ver tical Models) . . . . .

B. Cleaning and Inspection . . C. Reassemble as follows D. Cylinder Cover Removal and

6-5-1 6-5-1 6- 5-:-2

Reassembly ......... 6-5-2 E . 8- 1/2:1 Reduction Gear Mounting

Flange Removal. . . . • . . . 6-5-3 F. Early Model 8- 1/2: 1 Gear Reduc ­

tion Mounting Flange. . . . . G. Late Model 8-1/2:1 Reduction

Shaft Service . . . . . . . .

6- 5-3

6- 5- 4

SECTION 6. OIL SEAL SERVICE A. Oil Seal Replacement . .

SECTION 7. BEARING SERVICE A. Main Bearing Replacement B. Ball Bearing Service - 2 to 3-1/2

H. P. Horizontal Crankshaft Engine ... ....... .

C. Ball Bearing Service - 4-8 H. P . Horizontal Crankshaft Engine . .

Page

6- 6-1

6- 7 - 1

6- 7-4

6-7-4

PART VII . TROU BLESHOOTING

A. Common Troubles and Remedies . · · · 7-1-1

B. 4-Cycle Engine Troubleshooting Chart . · · . . · · 7-1-1

C. Troubleshooting Carburetion . · 7-1-5 D. Troubleshooting 12 Volt

Starters · · . · . 7- 1- 6 E . Troubleshooting 110 Volt Starter

System · · · . · 7-1 - 8

PART VIII. TABLE OF SPECIFICATIONS 8- 1- 1

Litho in U.S.A.

4-STROKE CYCLE ENGINE

SECTION 3. ENGINE CARE

Figure 1-4. 4-Cycle Operator's Maintenance Rules

TECUMSEH LAUSON DIY" NEW HOLSTEIN, WIS., U, S.A.

LUBRICATION: BEFORE STARTI NG FILL CRANK CASE TO TOP OF FILLER NEC K O R TO FULL MARK WHEN DIPSTIC K IS PROVIDED . BE SURE ENGINE

© IS LEV EL. ABOVE 32' F . USE MOBILOll A (SAE © 30) . BELOW 32' F. USE MO BILQllIOW . (SAE lOW) OR EQ UAL. US E CLASS MS O IL ONLY. C HANG E Oil AFTER FIRST 2 OP ERATI NG HRS. AND EVERY 5 OP ERA TI NG HRS. SPARK PLUG GAP.03 0" , BREAKER PO INT GAP ,020" .

J"I <JD1L V 60 -79 L}.. 9"J

~E;~JAL 700 L} Oc)O?Z

Figure 1-5. Typical 4- Cycle Engine Lubrication Ins tr uctions Decal

Litho in U. S. A.

A. MAINTENANCE RULES to insure proper engine operation.

These rules should be observed.

(1) Clean air filter regularly as required by operating conditions.

(2) Use clean , fresh gasoline . 4-Cycle En­gines - - DO NOT mix oil with gasoline.

(3) Use correct grade of motor oil, and make sure proper oil level is maintained.

(4) Keep vent hole in fuel tank cap open.

(5) Maintain proper cooling of engine. Keep engine shrouds free of dirt, grass, and other foreign matter.

(6) Clean engine as necessary to prevent carbon buildup.

(7) Make sure governor maintains correct speed range for application. Never run with a disconnected governor on governed models .

(8) Tighten all fasteners, espec ially mounting bolts, to keep damaging vibration at amin­imum.

(9) If dr iven equipment is balanced, vibration will be cut down considerably.

B. FUELS AND LUBRICANTS.

(1) Gasoline for all Tecumseh four - cycle en­gines regular grade leaded gasoline is recommended.

Non-leaded (lead fr ee) or low leaded gaso ­line is an acceptable substitute.

NOTE

Follow fuel and engine oil require ­ments listed in the Owners Manual and Operating Instructions .

(2) Engine Oil for all T ecumseh four-cycle engines use only a high quality, detergent oil having an engine service classification MS or SC, SD or SE.

Because of recent changes in the classifi­cations, the oil container may s how one or

1-3-1