Kohler HYDRO 12.75, CS4, CS8.5, CS10, CS12 User Manual

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COMMAND PRO CS

4-12.75 HP

HORIZONTAL CRANKSHAFT

SERVICE MANUAL

Section 1. Safety and General Information .............................................................................

Section 2. T ools & Aids ............................................................................................................

Section 3. T roubleshooting .....................................................................................................

Section 4. Air Cleaner and Air Intake System .........................................................................

Section 5. Fuel System and Governor ....................................................................................

Section 6. Lubrication System ................................................................................................

Section 7. Retractable Starter..................................................................................................

Section 8. Electrical System and Components......................................................................

Section 9. Disassembly............................................................................................................

Section 10. Internal Components............................................................................................

Section 11. Reassembly...........................................................................................................

Section 1

Safety and General Information

Safety Precautions

To ensure safe operations please read the following statements and understand their meaning. Also refer to your equipment owner's manual for other important safety information. This manual contains safety precautions which are explained below. Please read carefully.

WARNING

Warning is used to indicate the presence of a hazard that can cause severe personal injury, death, or substantial property damage if the warning is ignored.

CAUTION

Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the caution is ignored.

NOTE

Note is used to notify people of installation, operation, or maintenance information that is important but not hazard-related.

Section 1

For Y our Safety!

These precautions should be followed at all times. Failure to follow these precautions could result in injury to yourself and others.

WARNING

Accidental Starts can cause severe injury or death.

Disconnect and ground spark plug lead before servicing.

Accidental St arts!

Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-) battery cable from battery.

WARNING

Rotating Parts can cause severe injury.

Stay away while engine is in operation.

Rotating Part s!

Keep hands, feet, hair, and clothing away from all moving parts to prevent injury. Never operate the engine with covers, shrouds, or guards removed.

WARNING

Hot Parts can cause severe burns.

Do not touch engine while operating or just after stopping.

Hot Parts!

Engine components can get extremely hot from operation. To prevent severe burns, do not touch these areas while the engine is running—or immediately after it is turned off. Never operate the engine with heat shields or guards removed.

1.1

Section 1 Safety and General Information

WARNING

Explosive Fuel can cause fires and severe burns.

Do not fill the fuel tank while the engine is hot or running.

Explosive Fuel!

Gasoline is extremely flammable and its vapors can explode if ignited. Store gasoline only in approved containers, in well ventilated, unoccupied buildings, away from sparks or flames. Do not fill the fuel tank while the engine is hot or running, since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition. Do not start the engine near spilled fuel. Never use gasoline as a cleaning agent.

WARNING

Carbon Monoxide can cause severe nausea, fainting or death.

Avoid inhaling exhaust fumes, and never run the engine in a closed building or confined area.

Lethal Exhaust Gases!

Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled. Avoid inhaling exhaust fumes, and never run the engine in a closed building or confined area.

WARNING

Uncoiling Spring can cause severe injury.

Wear safety goggles or face protection when servicing retractable starter.

WARNING

Explosive Gas can cause fires and severe acid burns.

Charge battery only in a well ventilated area. Keep sources of ignition away.

Explosive Gas!

Batteries produce explosive hydrogen gas while being charged. To prevent a fire or explosion, charge batteries only in well ventilated areas. Keep sparks, open flames, and other sources of ignition away from the battery at all times. Keep batteries out of the reach of children. Remove all jewelry when servicing batteries.

Before disconnecting the negative (-) ground cable, make sure all switches are OFF. If ON, a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present.

Cleaning Solvents can cause severe injury or death.

Use only in well ventilated areas away from ignition sources.

Flammable Solvents!

Carburetor cleaners and solvents are extremely flammable. Keep sparks, flames, and other sources of ignition away from the area. Follow the cleaner manufacturer’s warnings and instructions on its proper and safe use. Never use gasoline as a cleaning agent.

Spring Under T ension!

Retractable starters contain a powerful, recoil spring that is under tension. Always wear safety goggles when servicing retractable starters and carefully follow instructions in the "Retractable Starter" Section 7 for relieving spring tension.

CAUTION

Electrical Shock can cause injury.

Do not touch wires while engine is running.

Electrical Shock!

Never touch electrical wires or components while the engine is running. They can be sources of electrical shock.

1.2

Engine Identification Numbers

When ordering parts, or in any communication involving an engine, always give the Model, Specification, and Serial Numbers of the engine.

The engine identification numbers appear on a decal (or decals) affixed to the engine shrouding. See Figure 1-1. An explanation of these numbers is shown in Figure 1-2.

Model Designation

Model CS6ST for example: C designates Command engine, S designates slanted cylinder configuration, and 6 designates horsepower. A suffix letter designates a specific version as follows:

Section 1

Safety and General Information

Identification Decal

Figure 1-1. Engine Identification Decal Location.

A. Model No.

Command Engine Slanted Cylinder Horsepower

4 = 4 HP 6 = 6 HP

8.5 = 8.5 HP 10 = 10 HP 12 = 12 HP

B. Spec. No.

Engine Model Code

Code Model

90 CS4 91 CS6 92 CS8.5# 300 cc 93 CS10 94 CS12 95 CS8.5# 250 cc

C. Serial No.

Year Manufactured Code

Code Year

28 1998 29 1999 30 2000 31 2001 32 2002

C S 6 ST

911509

28 23701265

Code Year

33 2003 34 2004 35 2005 36 2006 37 2007

Suffix Designates

T Retractable S tart

S Electric S tart G Tapered Crankshaft P Threaded Crankshaft R Gear Reduction (2:1 or 6:1)

IMPORTANT ENGINE INFORMATION THIS ENGINE MEETS U.S. EPA PHASE II, 2002-

2005 CALIFORNIA AND EC STAGE II (SN:4)

Variation of Basic Engine

EMISSION CONTROL REGS FOR SI SMALL OFF– ROAD ENGINES

FAMILY TYPE APP

MODEL NO. CS6ST SPEC. NO. 911509 DISPL. (CC) SERIAL NO. 2823701265 OEM PROD. NO.

EMISSION COMPLIANCE PERIOD: EPA: CATEGORY A

Factory Code

CERTIFIED ON: UNLEADED GASOLINE

REFER TO OWNER'S MANUAL FOR SAFETY, MAINTENANCE SPECS, AND ADJUSTMENTS

1-800-544-2444 www.kohlerengines.com

KOHLER CO. KOHLER, WISCONSIN USA

(REF:_______________ )

A B

N432

Figure 1-2. Explanation of Engine Identification Numbers.

NOTE: CS8.5 engines have been produced in two different specification series, 92xxxx and 95xxxx. The design

features of 92xxxx spec. no. engines are identical to CS10 and CS12 engines, and share the same service procedures. The 95xxxx spec. no. engines incorporate certain design differences from the 92xxxx spec. no. series. All service and repair information unique to the 95xxxx spec. no. series will be listed and covered separately.

1.3

Section 1 Safety and General Information

Oil Recommendations

Using the proper type and weight of oil in the crankcase is extremely important, as is checking oil daily and changing oil regularly. Failure to use the correct oil or using dirty oil, causes premature engine wear and failure.

Oil Type

Use high quality detergent oil of API (American Petroleum Institute) service class SG, SH, SJ or higher. Select the viscosity based on the air

temperature at the time of operation as shown below.

Synthetic oils should not be used.

Figure 1-3. Viscosity Grades Table.

Fuel Recommendations

WARNING: Explosive Fuel!

General Recommendations

Purchase gasoline in small quantities and store in clean, approved containers. A container with a capacity of 2 gallons or less with a pouring spout is recommended. Such a container is easier to handle and helps eliminate spillage during refueling.

Do not use gasoline left over from the previous season, to minimize gum deposits in your fuel system and to insure easy starting.

Do not add oil to the gasoline.

Do not overfill the fuel tank. Leave room for the fuel to expand.

NOTE: Using other than service class SG, SH, SJ or

higher oil or extending oil change intervals longer than recommended can cause engine damage.

A logo or symbol on oil containers identifies the API service class and SAE viscosity grade. See Figure 1-4.

Figure 1-4. Oil Container Logo.

Refer to Section 6 - ‘‘Lubrication System’’ for detailed oil check and oil change procedures.

Fuel T yp e

For best results, use only clean, fresh, unleaded gasoline with a pump sticker octane rating of 87 or higher. In countries using the Research method, it should be 90 octane minimum.

Unleaded gasoline is recommended, as it leaves less combustion chamber deposits. Leaded gasoline may be used in areas where unleaded is not available and exhaust emissions are not regulated. Be aware however, that the cylinder head will require more frequent service.

Gasoline/Alcohol blends

Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) is approved as a fuel for Kohler engines. Other gasoline/alcohol blends are not approved.

Gasoline/Ether blends

Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to maximum of 15% MTBE by volume) are approved as a fuel for Kohler engines. Other gasoline/ether blends are not approved.

1.4

Maintenance Instructions

Section 1

Safety and General Information

WARNING: Accident al Starts!

Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead (s). 2) Disconnect negative (-) battery cable from battery.

Maintenance Schedule

These required maintenance procedures should be performed at the frequency stated in the table. They should also be included as part of any seasonal tune-up.

Daily or Before

Starting Engine

Every 25 Hours

Every 50 Hours

Every 100 Hours

Maintenance RequiredFrequency

• Fill fuel tank.

• Check oil level.

• Check air cleaner for dirty, loose, or damaged parts.

• Check air intake and cooling areas, clean as necessary.

• Service precleaner element. Replace if necessary.

• Service solid foam element. Replace if necessary.

• Change oil.

• Replace air cleaner element.

• Remove cooling shrouds and clean cooling areas.

• Check all fittings and fasteners.

• Clean fuel shut-off valve filter. Replace if necessary.

Refer to:

Section 5 Section 6 Section 4 Section 4

Section 4

Section 4 Section 6

Section 4 Section 4 Section 1 Section 5

• Check muffler screen/spark arrestor. Clean/replace if necessary. Section 8

Section 11 Section 5 Section 7

Annually or

Every 300 Hours

• Check spark plug condition and gap. Replace if necessary.

• Check and adjust valve clearance when engine is cold.

• Check and adjust idle speed.

• Service starter motor drive, if so equipped.

• Have combustion chamber decarbonized.

¹Perform these maintenance procedures more frequently under extremely dusty, dirty conditions. ²Have a Kohler Engine Service Dealer perform this service.

Storage

If the engine will be out of service for two months or more, use the following storage procedure:

1. Clean the exterior surfaces of the engine.

2. Change the oil while the engine is still warm from operation. See ‘‘Change Oil’’ on page 6.2.

3. The fuel system must be completely emptied, or the gasoline must be treated with a stabilizer to prevent deterioration. If you choose to use a stabilizer, follow the manufacturers recommendations, and add the correct amount for the capacity of the fuel system. Fill the fuel tank with clean, fresh gasoline. Run the engine for 2-3 minutes to get stabilized fuel into the carburetor.

To empty the system, run the engine until the tank and system are empty.

4. Remove the spark plug. Add one tablespoon of engine oil into the spark plug hole. Install the plug, but do not connect the plug lead. Crank the engine two or three revolutions and then turn it up against compression (when highest pull force or cranking force is required).

5. Store the engine in a clean, dry place.

1.5

Section 1 Safety and General Information

347.00 (13.661)

373.00 (14.685)

66.00 (2.598)

162.00 (6.378)

321.50 (Straight PTO) (12.657)

143.00 (5.630)

100.00 (3.937)

162.00 (6.378)

30.00 (1.181)

106.00 (4.173)

5/16-24 [qty. 5] 14 mm (.551) deep

384.25 (15.128)

Spark Plug

Oil Fill

Oil Drain Plug

Mounting Face

5.00 (.197)

44.50 (1.752)

37.00 (1.457)

9.0 (.354) dia. [qty. 2]

9.0x14.0 (.354x.551) slot [qty.2]

80.00 (3.150)

Figure 1-5. T ypical Engine Dimensions CS4 and CS6.

145.25 (5.719)

380.03 (14.962)

Dimensions in millimeters. Inch equivalents shown in ( ).

1.6

452.90 (17.831)

Section 1

Safety and General Information

454.00 (17.874)

445.85

156.68 (6.168)

45°

30°

(17.553)

45°

30°

423.50 (16.673)

70.00 (2.756)

Spark Plug

Oil Fill

417.50 (Straight PTO) (16.437)

187.50 (7.382)

118.34 (4.659)

99.00 (3.898)

205.00 (8.071)

133.50 (5.256)

5/16-24 [qty. 4] 18 mm (.709) deep

3/8-16 [qty. 4] 18 mm (.709) deep

127.00 (5.000) dia.

110.00 (4.331) dia.

90.50 (3.563)

195.50 (7.697)

152.00 (5.984)

165.10 (6.500) dia.

5/16-24 [qty. 2] 18 mm (.709) deep

146.08 (5.751) dia.

103.00 (4.055)

298.00 (11.732)

Oil Drain Plug

Mounting Face

16.00 (.630)

37.00 (1.457)

62.00 (2.441)

102.00 (4.016)

11.00 (.433) dia. [qty. 2]

11.00x27 (.433x1.063) slot [qty. 2]

65.00 (2.559)

Dimensions in millimeters. Inch equivalents shown in ( ).

Figure 1-6. T ypical Engine Dimensions CS8.5 (spec. 92xxxx), CS10, and CS12 - 12.75.

1.7

Section 1 Safety and General Information

431.00

156.00 (6.142)

165.1 (6.50)

(16.968)

110 (4.33)

410.00 (16.142)

428.00 (16.850)

3/8-16 18 mm (.709) deep [qty. 4]

183.00 (7.205)

94.5

(3.720)

133.50 (5.256)

380.00 (14.961)

146.08 (5.78)

90.50

(3.563)

195.50 (7.697)

103.00

(4.055)

424.00 (16.693)

70.00 (2.756)

5/16-24 18 mm (.709) deep [qty. 2]

5/16-24 18 mm (.709) deep [qty. 4]

11.00x27.00

(.433x1.063)

slotted hole

[qty. 2]

16.00 (.630)

37.00 (1.457)

57.50 (2.264)

96.00

(3.780)

11 (.433) hole [qty. 2]

59.00 (2.323)

Figure 1-7. T ypical Engine Dimensions CS8.5 (spec. 95xxxx).

1.8

Dimensions in millimeters. Inch equivalents shown in ( ).

Safety and General Information

General Specifications

Power (@ 3600 RPM, exceeds SAE J1940 HP Standards)

CS4 ............................................................................................................. 2.9 kW (4 HP)

CS6 ............................................................................................................. 4.47 kW (6 HP)

CS8.5 (spec. 95xxxx) ................................................................................ 5.40 kW (8.5 HP)

CS8.5 (spec. 92xxxx) ................................................................................ 6.33 kW (8.5 HP)

CS10 ........................................................................................................... 7.45 kW (10 HP)

CS12 ........................................................................................................... 8.95 kW (12 HP)

Hydro 12.75 .............................................................................................. 9.5 kW (12.75 HP)

Peak Torque

CS4 (@ 2000 RPM) .................................................................................... 7.6 N·m (5.6 ft. lb.)

CS6 (@ 2000 RPM) .................................................................................... 10.8 N·m (8 ft. lb.)

CS8.5 (spec. 95xxxx @ 2400 RPM) .......................................................... 16.5 N·m (12.1 ft. lb.)

CS8.5 (spec. 92xxxx @ 2000 RPM) .......................................................... 19.66 N·m (14.5 ft. lb.)

CS10 (@ 2000 RPM).................................................................................. 19.66 N·m (14.5 ft. lb.)

CS12 (spec. 9415xx @ 2000 RPM) ........................................................... 22.6 N·m (16.7 ft. lb.)

CS12 (spec. 9416xx @ 2400 RPM) ........................................................... 24.9 N·m (18.4 ft. lb.)

Hydro 12.75 (@ 2400 RPM) ..................................................................... 30.6 N·m (22.6 ft. lb.)

Bore

CS4 ............................................................................................................. 56.0 mm (2.20 in.)

CS6 ............................................................................................................. 66.0 mm (2.60 in.)

CS8.5 (spec. 95xxxx) ................................................................................ 75.0 mm (2.95 in.)

CS8.5 (spec. 92xxxx) ................................................................................ 78.0 mm (3.07 in.)

CS10 ........................................................................................................... 78.0 mm (3.07 in.)

CS12 ........................................................................................................... 85.0 mm (3.35 in.)

Section 1

Stroke

CS4,CS6 ..................................................................................................... 50.0 mm (1.97 in.)

CS8.5 (spec. 95xxxx) ................................................................................ 57.0 mm (2.44 in.)

CS8.5 (spec. 92xxxx) ................................................................................ 63.0 mm (2.48 in.)

CS10-12...................................................................................................... 63.0 mm (2.48 in.)

Displacement

CS4 ............................................................................................................. 123 cc (7.50 cu. in.)

CS6 ............................................................................................................. 171 cc (10.43 cu. in.)

CS8.5 (spec. 95xxxx) ................................................................................ 251 cc (15.30 cu. in.)

CS8.5 (spec. 92xxxx) ................................................................................ 301 cc (18.37 cu. in.)

CS10 ........................................................................................................... 301 cc (18.37 cu. in.)

CS12 ........................................................................................................... 357 cc (21.79 cu. in.)

Compression Ratio

CS4 ............................................................................................................. 8.3:1

CS6 ............................................................................................................. 8.5:1

CS8.5 (spec. 95xxxx) ................................................................................ 8.3:1

CS8.5 (spec. 92xxxx) ................................................................................ 8.1:1

CS10-12...................................................................................................... 8.1:1

Weight (Approx.)

CS4,CS6 ..................................................................................................... 15.4 kg (35 lb.)

CS8.5 (spec. 95xxxx) ................................................................................ 26 kg (57.2 lb.)

CS8.5 (spec. 92xxxx) ................................................................................ 31.9 kg (70.5 lb.)

CS10-12...................................................................................................... 31.9 kg (70.5 lb.)

1.9

Section 1 Safety and General Information

General Specifications cont.

Oil Capacity (Approx.)

CS4,CS6 ..................................................................................................... 0.6 L (0.64 U.S. qt.)

CS8.5 (spec. 95xxxx) ................................................................................ 1.0 L (1.1 U.S. qt.)

CS8.5 (spec. 92xxxx) ................................................................................ 1.1 L (1.2 U.S. qt.)

CS10-12...................................................................................................... 1.1 L (1.2 U.S. qt.)

Fuel Tank Capacity

CS4,CS6 ..................................................................................................... 3.9 L (4.1 U.S. qt.)

CS8.5 (spec. 95xxxx) ................................................................................ 6.0 L (6.3 U.S. qt.)

CS8.5 (spec. 92xxxx) ................................................................................ 6.9 L (7.3 U.S. qt.)

CS10-12...................................................................................................... 6.9 L (7.3 U.S. qt.)

Angle of Operation – Maximum (At Full Oil Level) All Directions........ 20°

Air Cleaner

Base Bolt Torque ............................................................................................. 5-8 N·m (44-71 in. lb.)

Base Nut Torque

CS4,CS6 ..................................................................................................... 5-8 N·m (44-71 in. lb.)

CS8.5 (spec. 95xxxx) ................................................................................ 5-8 N·m (44-71 in. lb.)

CS8.5 (spec. 92xxxx) ................................................................................ 10-12 N·m (88-106 in. lb.)

CS10-12...................................................................................................... 10-12 N·m (88-106 in. lb.)

Camshaft

End Play ........................................................................................................... 0.05 mm (0.0020 in.)

Bore I.D. – Max. Wear Limit

CS4,CS6 ..................................................................................................... 14.95 mm (0.583 in.)

CS8.5-12..................................................................................................... 15.95 mm (0.627 in.)

Camshaft Bearing Surface O.D. – Max. Wear Limit

CS4,CS6 ..................................................................................................... 15.05 mm (0.592 in.)

CS8.5-12..................................................................................................... 16.05 mm (0.649 in.)

Carburetor

Fuel Bowl Retaining Screw Torque

CS4,CS6 ..................................................................................................... 7 N·m (62 in. lb.)

CS8.5-12..................................................................................................... 9 N·m (79 in. lb.)

Throttle/Choke Plate Screws Torque ........................................................... 1.5-2.5 N·m (13-22 in. lb.)

Connecting Rod

Connecting Rod Fastener Torque

CS4,CS6 ..................................................................................................... 12 N·m (106 in. lb.)

CS8.5 (spec. 95xxxx) ................................................................................ 12 N·m (106 in. lb.)

CS8.5 (spec. 92xxxx) ................................................................................ 20 N·m (177 in. lb.)

CS10-12...................................................................................................... 20 N·m (177 in. lb.)

Connecting Rod-to-Crankpin Running Clearance

New ........................................................................................................... 0.016/0.046 mm (0.0006/0.0018 in.)

Max. Wear Limit ...................................................................................... 0.1 mm (0.004 in.)

Connecting Rod-to-Crankpin Side Clearance

CS4,CS6 ..................................................................................................... 0.2/0.6 mm (0.008/0.024 in.)

CS8.5 (spec. 95xxxx) ................................................................................ 0.2/0.6 mm (0.008/0.024 in.)

CS8.5 (spec. 92xxxx) ................................................................................ 0.2/0.65 mm (0.0079/0.0256 in.)

CS10-12...................................................................................................... 0.2/0.65 mm (0.0079/0.0256 in.)

1.10

Section 1

Safety and General Information

Connecting Rod cont.

Connecting Rod-to-Piston Pin Running Clearance.................................... 0.006/0.025 mm (0.0002/0.0001 in.)

Piston Pin End I.D.

New

CS4,CS6 .............................................................................................. 16.006/16.020 mm (0.6301/0.6307 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 18.006/18.020 mm (0.7089/0.7094 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 20.006/20.020 mm (0.7876/0.7882 in.)

CS10-12 .............................................................................................. 20.006/20.020 mm (0.7876/0.7882 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 16.10 mm (0.634 in.)

CS8.5 (95xxxx) ................................................................................... 18.10 mm (0.713 in.)

CS8.5 (92xxxx) ................................................................................... 20.10 mm (0.791 in.)

CS10-12 .............................................................................................. 20.10 mm (0.791 in.)

Connecting Rod Journal End I.D.

New

CS4,CS6 .............................................................................................. 28.000/28.015 mm (1.1023/1.1029 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 32.000/32.015 mm (1.2598/1.2604 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 36.000/36.015 mm (1.4173/1.4179 in.)

CS10-12 .............................................................................................. 36.000/36.015 mm (1.4173/1.4179 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 28.115 mm (1.1069 in.)

CS8.5 (95xxxx) ................................................................................... 32.115 mm (1.2644 in.)

CS8.5 (92xxxx) ................................................................................... 36.115 mm (1.4219 in.)

CS10-12 .............................................................................................. 36.115 mm (1.4219 in.)

Crankcase

Closure Plate Fastener Torque

CS4,CS6 ..................................................................................................... 22 N·m (195 in. lb.)

CS8.5-12..................................................................................................... 30 N·m (265 in. lb.)

Oil Drain Plugs Torque

CS4,CS6 ..................................................................................................... 17 N·m (150 in. lb.)

CS8.5-12..................................................................................................... 20 N·m (177 in. lb.)

Crankshaft

End Play (Free) ................................................................................................ 0.04 mm (0.0015 in.)

End Play (Threaded Pump Shaft Models Only) ......................................... 0.0/0.2 mm (0.0/0.007 in.)

Flywheel End Main Bearing Journal O.D.

New

CS4,CS6 .............................................................................................. 52 mm (2.047 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 52 mm (2.047 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 80 mm (3.149 in.)

CS10-12 .............................................................................................. 80 mm (3.149 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 52.05 mm (2.0492 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 52.05 mm (2.0492 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 80.05 mm (3.1515 in.)

CS10-12 .............................................................................................. 80.05 mm (3.1515 in.)

1.11

Section 1 Safety and General Information

Crankshaft cont.

PTO End Main Bearing Journal O.D.

New

CS4,CS6 .............................................................................................. 52 mm (2.047 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 52 mm (2.047 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 72 mm (2.834 in.)

CS10-12 .............................................................................................. 72 mm (2.834 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 52.05 mm (2.0492 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 52.05 mm (2.0492 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 72.05 mm (2.836 in.)

CS10-12 .............................................................................................. 72.05 mm (2.836 in.)

Connecting Rod Journal O.D.

New

CS4,CS6 .............................................................................................. 27.969/27.984 mm (1.011/1.017 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 31.969/31.984 mm (1.2586/1.2592 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 35.969/35.984 mm (1.4161/1.4167 in.)

CS10-12 .............................................................................................. 35.969/35.984 mm (1.4161/1.4167 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 27.9 mm (1.098 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 31.9 mm (1.2559 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 35.9 mm (1.4134 in.)

CS10-12 .............................................................................................. 35.9 mm (1.4134 in.)

Crankshaft

Runout (Either End) ................................................................................ 0.02 mm (0.0008 in.)

Limit (Either End) .................................................................................... 0.04 mm (0.0016 in.)

Cylinder Bore

Cylinder Bore I.D.

New

CS4 ...................................................................................................... 56.005/56.015 mm (2.2049/2.2053 in.)

CS6 ...................................................................................................... 66.005/66.015 mm (2.5986/2.5990 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 75.005/75.015 mm (2.9530/2.9533 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 78.00/78.02 mm (3.0709/3.0717 in.)

CS10 .................................................................................................... 78.00/78.02 mm (3.0709/3.0717 in.)

CS12 .................................................................................................... 85.00/85.02 mm (3.3465/3.3472 in.)

Max. Wear Limit

CS4 ...................................................................................................... 56.15 mm (2.211 in.)

CS6 ...................................................................................................... 66.15 mm (2.604 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 75.15 mm (2.959 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 78.65 mm (3.096 in.)

CS10 .................................................................................................... 78.65 mm (3.096 in.)

CS12 .................................................................................................... 85.65 mm (3.372 in.)

Max. Out-of-Round ................................................................................. 0.05 mm (0.002 in.)

Cylinder Head

Cylinder Head Bolt Torque

CS4,CS6 ..................................................................................................... 20 N·m (177 in. lb.)

CS8.5-12..................................................................................................... 50 N·m (36 ft. lb.)

Max. Out-of-Flatness ...................................................................................... 0.1 mm (0.004 in.)

Electric Starter

Thru Bolt (Case) Torque

CS8.5-12..................................................................................................... 5.3 N·m (47.7 in. lb.)

1.12

Safety and General Information

Electric Starter cont.

Mounting Bolts (To Block) Torque

CS8.5-12..................................................................................................... 16 N·m (141 in. lb.)

Flywheel

Flywheel Retaining Screw Torque

CS4,CS6 ..................................................................................................... 65 N·m (48 ft. lb.)

CS8.5 (spec. 95xxxx) ................................................................................ 65 N·m (48 ft. lb.)

CS8.5 (spec. 92xxxx) ................................................................................ 120 N·m (85 ft. lb.)

CS10-12...................................................................................................... 120 N·m (85 ft. lb.)

Fuel Tank

Fuel Tank Fastener Screws Torque ............................................................... 8-12 N·m (71-106 in. lb.)

Ignition

Spark Plug Type

NGK ........................................................................................................... BPR4ES (13/16 hex)

Champion®............................................................................................... RN14YC (13/16 hex)

Champion®............................................................................................... RC14YC (5/8) hex)

Spark Plug Gap ............................................................................................... 0.76 mm (0.030 in.)

Section 1

Spark Plug Torque .......................................................................................... 20 N·m (14.7 ft. lb./177 in. lb.)

Ignition Module Air Gap ............................................................................... 0.4/0.6 mm (0.015/0.023 in.)

Ignition Module Mounting Screws Torque ................................................. 10 N·m (88 in. lb.)

Stator Mounting Screw Torque ..................................................................... 5-8 N·m (44-70 in. lb.)

Muffler

Muffler Torque (Flange Nuts & Bracket Bolts)

CS4,CS6 ..................................................................................................... 8-12 N·m (71-106 in. lb.)

CS8.5-12..................................................................................................... 18-22 N·m (159-195 in. lb.)

Oil Sentry

Oil Sentry™Float Switch Torque ................................................................... 10 N·m (88 in. lb.)

Oil Sentry™Indicator Light Retaining Nut Torque .................................... 0.6-0.8 N·m (5-7 in. lb.)

Piston, Piston Rings, and Piston Pin

Piston-to-Piston Pin Clearance

Piston Pin Bore I.D.

™

CS4,CS6 ..................................................................................................... 0.002/0.018 mm (0.0001/0.0007 in.)

CS8.5-12..................................................................................................... 0.004/0.020 mm (0.0002/0.0008 in.)

New

CS4,CS6 .............................................................................................. 16.002/16.013 mm (0.6300/0.6304 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 18.004/18.015 mm (0.7088/0.7093 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 20.004/20.015 mm (0.7876/0.7880 in.)

CS10-12 .............................................................................................. 20.004/20.015 mm (0.7876/0.7880 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 16.03 mm (0.6311 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 18.03 mm (0.7098 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 20.03 mm (0.7886 in.)

CS10-12 .............................................................................................. 20.03 mm (0.7886 in.)

1.13

Section 1 Safety and General Information

Piston, Piston Rings, and Piston Pin cont.

Piston Pin O.D.

New

CS4,CS6 .............................................................................................. 15.995/16.000 mm (0.6297/0.6299 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 17.995/18.000 mm (0.7084/0.7086 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 19.995/20.000 mm (0.7872/0.7874 in.)

CS10-12 .............................................................................................. 19.995/20.000 mm (0.7872/0.7874 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 15.98 mm (0.6291 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 17.98 mm (0.7079 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 19.98 mm (0.7866 in.)

CS10-12 .............................................................................................. 19.98 mm (0.7866 in.)

Top Compression Ring-to-Groove Side Clearance .................................... 0.04/0.08 mm (0.0016/0.003 in.)

Middle Compression Ring-to-Groove Side Clearance

CS4,CS6 ..................................................................................................... 0.02/0.06 mm (0.0008/0.0024 in.)

CS8.5-12..................................................................................................... 0.03/0.07 mm (0.0012/0.0028 in.)

Top Compression Ring End Gap

CS4,CS6 ..................................................................................................... 0.2/0.4 mm (0.008/0.016 in.)

CS8.5 (spec. 95xxxx) ................................................................................ 0.25/0.4 mm (0.010/0.016 in.)

CS8.5 (spec. 92xxxx) ................................................................................ 0.2/0.4 mm (0.008/0.016 in.)

CS10 ........................................................................................................... 0.2/0.4 mm (0.008/0.016 in.)

CS12 ........................................................................................................... 0.25/0.4 mm (0.010/0.016 in.)

Middle Compression Ring End Gap

CS4,CS6 ..................................................................................................... 0.2/0.4 mm (0.008/0.016 in.)

CS8.5 (spec. 95xxxx) ................................................................................ 0.25/0.4 mm (0.010/0.016 in.)

CS8.5 (spec. 92xxxx) ................................................................................ 0.2/0.4 mm (0.008/0.016 in.)

CS10 ........................................................................................................... 0.2/0.4 mm (0.008/0.016 in.)

CS12 ........................................................................................................... 0.25/0.4 mm (0.010/0.016 in.)

Oil Control Ring End Gap

CS4,CS6 ..................................................................................................... 0.2/0.4 mm (0.0079/0.0157 in.)

CS8.5-12..................................................................................................... 0.2/0.7 mm (0.0079/0.028 in.)

Piston Thrust Face O.D.

New

CS42..................................................................................................... 55.975/55.990 mm (2.2037/2.2043 in.)

CS62..................................................................................................... 65.975/65.990 mm (2.597/2.598 in.)

CS8.53 (spec. 95xxxx) ........................................................................ 74.954/74.998 mm (2.9509/2.9527 in.)

CS8.53 (spec. 92xxxx) ........................................................................ 77.954/77.998 mm (3.0691/3.0708 in.)

CS103................................................................................................... 77.954/77.998 mm (3.0691/3.0708 in.)

CS123................................................................................................... 84.954/84.998 mm (3.3446/3.3464 in.)

Max. Wear Limit

CS4 ...................................................................................................... 55.900 mm (2.20 in.)

CS6 ...................................................................................................... 65.900 mm (2.60 in.)

CS8.5 (spec. 95xxxx) ......................................................................... 74.898 mm (2.9487 in.)

CS8.5 (spec. 92xxxx) ......................................................................... 77.898 mm (3.0669 in.)

CS10 .................................................................................................... 77.898 mm (3.0669 in.)

CS12 .................................................................................................... 84.898 mm (3.3424 in.)

Piston Thrust Face-to-Cylinder Bore Running Clearance

CS4,CS62.................................................................................................... 0.015/0.040 mm (0.0006/0.0016 in.)

CS8.5-123................................................................................................... 0.002/0.066 mm (0.0001/0.0026 in.)

1.14

Safety and General Information

Reduction System

Case Mounting Bolt(s) Torque

CS4,CS6 ..................................................................................................... 10 N·m (88 in. lb.)

CS8.5-12..................................................................................................... 30 N·m (22 ft. lb.)

Crankshaft Gear Bolt Torque

CS4,CS6 ..................................................................................................... 22 N·m (195 in. lb.)

CS8.5 (spec. 95xxxx) ................................................................................ 22 N·m (195 in. lb.)

CS8.5 (spec. 92xxxx) ................................................................................ 65 N·m (48 ft. lb.)

CS10-12...................................................................................................... 65 N·m (48 ft. lb.)

Retractable St arter

Mounting Screws to Blower Housing Torque

CS4,CS6 ..................................................................................................... 6.5 N·m (57 in. lb.)

CS8.5-12..................................................................................................... 7 N·m (62 in. lb.)

Rocker Arm

Stud Into Cylinder Head Torque

CS4,CS6 ..................................................................................................... 10 N·m (88 in. lb.)

Adjusting Jam Nut Torque ............................................................................ 7 N·m (62 in. lb.)

Section 1

Throttle Control

Throttle Control Lever Fastener Torque

CS4,CS6 ..................................................................................................... 7-9 N·m (62-80 in. lb.)

CS8.5-12..................................................................................................... 9-11 N·m (80-97 in. lb.)

Valve Cover

Valve Cover Fastener Torque

CS4,CS6 ..................................................................................................... 10 N·m (88 in. lb.)

CS8.5-12..................................................................................................... 11 N·m (97 in. lb.)

Valves and Valve Lifters

Intake Valve Stem-to-Valve Guide Running Clearance

CS4,CS6 ..................................................................................................... 0.04/0.06 mm (0.0016/0.0024 in.)

CS8.5-12..................................................................................................... 0.037/0.064 mm (0.0015/0.0025 in.)

Exhaust Valve Stem-to-Valve Guide Running Clearance

CS4,CS6 ..................................................................................................... 0.06/0.08 mm (0.002/0.003 in.)

CS8.5-12..................................................................................................... 0.045/0.072 mm (0.0018/0.0028 in.)

Intake Valve Guide I.D.

New

CS4,CS6 .............................................................................................. 5.5 mm (0.22 in.)

CS8.5-12 ............................................................................................. 6.0/6.012 mm (0.2362/0.2367 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 5.60 mm (0.220 in.)

CS8.5-12 ............................................................................................. 6.10 mm (0.240 in.)

Exhaust Valve Guide I.D.

New

CS4,CS6 .............................................................................................. 5.5 mm (0.22 in.)

CS8.5-12 ............................................................................................. 6.0/6.012 mm (0.2362/0.2367 in.)

Max. Wear Limit

CS4,CS6 .............................................................................................. 5.6 mm (0.220 in.)

CS8.5-12 ............................................................................................. 6.0 mm (0.236 in.)

1.15

Section 1 Safety and General Information

Valves and Valve Lifters

Valve Guide Reamer Size

STD

CS4,CS6 .............................................................................................. 5.5 mm (0.216 in.)

CS8.5-12 ............................................................................................. 6.0 mm (0.236 in.)

Intake Valve Minimum Lift

CS4,CS6 ..................................................................................................... 2.4 mm (0.094 in.)

CS8.5-12..................................................................................................... 2.7 mm (0.106 in.)

Exhaust Valve Minimum Lift

CS4,CS6 ..................................................................................................... 2.7 mm (0.106 in.)

CS8.5-12..................................................................................................... 2.9 mm (0.114 in.)

Nominal Valve Seat Angle ............................................................................. 45°

Valve-to-Tappet Clearance (Cold) ................................................................ 0.1 mm (0.004 in.)

Notes:

1. Values are in Metric units. Values in parenthesis are English equivalents. Lubricate threads with engine oil prior to assembly.

2. Measure 5 mm (0.197 in.) above the bottom of the piston skirt at right angles to the piston pin.

3. Measure 10 mm (0.394 in.) above the bottom of the piston skirt at right angles to the piston pin.

Oil Drain Plugs Tightening Torque: N·m (in. lb.)

Size M10x1.25 M12x1.50

Into Aluminum

17 (150) 20 (177)

Model

CS4, CS6

CS8.5, CS10, CS12

Torque

Conversions

N·m = in. lb. x 0.113 N·m = ft. lb. x 1.356 in. lb. = N·m x 8.85 ft. lb. = N·m x 0.737

1.16

Section 2

Tools & Aids

Section 2

Tools & Aids

Certain quality tools are designed to help you perform specific disassembly, repair, and reassembly procedures. By using tools designed for the job, you can properly service engines easier, faster, and safer! In addition, you’ll increase your service capabilities and customer satisfaction by decreasing engine downtime.

Here is the list of tools and their source.

Separate Tool Suppliers:

Kohler Tools Contact your source of supply.

SE Tools 415 Howard St. Lapeer, MI 48446 Phone 810-664-2981 Toll Free 800-664-2981 Fax 810-664-8181

Design Technology Inc. 768 Burr Oak Drive Westmont, IL 60559 Phone 630-920-1300

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Section 2 Tools & Aids

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Section 2

Tools & Aids

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2.3

Section 2 Tools & Aids

Special Tools You Can Make

Flywheel Holding T ool (Electric S tart Models Only)

A flywheel holding tool can be made out of an old junk flywheel ring gear as shown in Figure 2-1, and used in place of a strap wrench.

1. Using an abrasive cut-off wheel, cut out a six tooth segment of the ring gear as shown.

2. Grind off any burrs or sharp edges.

3. Invert the segment and place it between the ignition bosses on the crankcase so that the tool teeth engage the flywheel ring gear teeth. The bosses will lock the tool and flywheel in position for loosening, tightening or removing with a puller.

2. Remove the studs of a Posi-Lock rod or grind off the aligning steps of a Command rod, so the joint surface is flat.

3. Find a 1 in. long capscrew with the correct thread size to match the threads in the connecting rod.

4. Use a flat washer with the correct I.D. to slip on the capscrew and approximately 1” O.D. (Kohler Part No. 12 468 05-S). Assemble the capscrew and washer to the joint surface of the rod, as shown in Figure 2-2.

Figure 2-1. Flywheel Holding Tool.

Rocker Arm/Crankshaft Tool

A spanner wrench to lift the rocker arms or turn the crankshaft may be made out of an old junk connecting rod.

1. Find a used connecting rod from a 10 HP or larger engine. Remove and discard the rod cap.

Figure 2-2. Rocker Arm/Crankshaf t T ool.

2.4

Section 3

Troubleshooting

Section 3

Troubleshooting

Troubleshooting Guide

When troubles occur, be sure to check the simple causes which, at first, may seem too obvious to be considered. For example, a starting problem could be caused by an empty fuel tank.

Some common causes of engine trouble are listed below. Use these to locate the causing factors.

Engine Cranks But Will Not Start

1. Empty fuel tank.

2. Fuel shut-off valve closed.

3. Key switch or kill switch in “off” position.

4. Low oil level.

5. Dirt or water in the fuel system.

6. Clogged fuel line.

7. Spark plug lead disconnected.

8. Faulty spark plug.

9. Faulty ignition module.

Engine Start s But Does Not Keep Running

1. Restricted fuel cap vent.

2. Dirt or water in the fuel system.

3. Faulty choke or throttle controls.

4. Loose wires or connections that short the kill terminal of ignition module to ground.

5. Faulty cylinder head gasket.

6. Faulty carburetor.

Engine Start s Hard

1. PTO drive is engaged.

2. Dirt or water in the fuel system.

3. Clogged fuel line.

4. Loose or faulty wires or connections.

5. Faulty choke or throttle controls.

6. Faulty spark plug.

7. Low compression.

8. Faulty ACR mechanism.

9. Weak spark/ignition.

Engine Will Not Crank

1. PTO drive is engaged.

2. Battery (if equipped) is discharged.

3. Safety interlock switch is engaged.

4. Loose or faulty wires or connections.

5. Faulty key switch or ignition switch.

6. Faulty electric starter or solenoid (electric start).

7. Pawls not engaging in drive cup (retractable start).

8. Seized internal engine components.

Engine Runs But Misses

1. Dirt or water in the fuel system.

2. Spark plug lead loose.

3. Loose wires or connections that intermittently short the kill terminal of ignition module to ground.

4. Engine overheated.

5. Faulty ignition module.

6. Faulty spark plug.

7. Carburetor malfunction.

Engine Will Not Idle

1. Restricted fuel cap vent.

2. Dirt or water in the fuel system.

3. Faulty spark plug.

4. Idle fuel adjusting needle improperly set.

5. Idle speed adjusting screw improperly set.

6. Low compression.

7. Stale fuel and/or gum in carburetor.

Engine Overheats

1. Air intake/grass screen, cooling fins, or cooling shrouds clogged.

2. Excessive engine load.

3. Low crankcase oil level.

4. High crankcase oil level.

5. Faulty carburetor.

Engine Knocks

1. Excessive engine load.

2. Low crankcase oil level.

3. Old/improper fuel.

4. Internal wear or damage.

3.1

Section 3 Troubleshooting

Engine Loses Power

1. Low crankcase oil level.

2. High crankcase oil level.

3. Dirty air cleaner element.

4. Dirt or water in the fuel system.

5. Excessive engine load.

6. Engine overheating.

7. Faulty spark plug.

8. Low compression.

9. Exhaust restriction.

Engine Uses Excessive Amount Of Oil

1. Incorrect oil viscosity/type.

2. Overfilled crankcase.

3. Clogged breather.

4. Worn or broken piston rings.

5. Worn cylinder bore.

6. Worn valve stems/valve guides.

Oil Leaks From Oil Seals, Gaskets

1. Crankcase breather is clogged or inoperative.

2. Loose or improperly torqued fasteners.

3. Piston blowby or leaky valves.

4. Restricted exhaust.

External Engine Inspection

Before cleaning or disassembling the engine, make a thorough inspection of its external appearance and condition. This inspection can give clues to what might be found inside the engine (and the cause) when it is disassembled.

• Check for buildup of dirt and debris on the crankcase, cooling fins, grass screen and other external surfaces. Dirt or debris on these areas are causes of overheating.

• Check for obvious fuel and oil leaks, and damaged components. Excessive oil leakage can indicate a clogged or improperly assembled breather, worn or damaged seals and gaskets, or loose or improperly torqued fasteners.

• Check the air cleaner cover and base for damage or indications of improper fit or sealing.

• Check the air cleaner element. Look for holes, tears, cracked or damaged sealing surfaces, or other damage that could allow unfiltered air into the engine. Also note if the element is dirty or clogged. These could indicate that the engine has had inadequate or infrequent maintenance.

• Check the carburetor throat for dirt. Dirt in the throat is further indication that the air cleaner was not functioning properly.

• Check the oil level. Note if the oil level is within the operating range on the dipstick, or if it is low or overfilled.

• Check the condition of the oil. Drain the oil into a container - the oil should flow freely. Dark, dirty, and/or thick oil could indicate infrequent maintenance or overheating. Check for metal chips and other foreign particles.

Sludge is a natural by-product of combustion; a small accumulation is normal. Excessive sludge formation could indicate the oil has not been changed at the recommended intervals, the incorrect type or weight of oil was used, overrich carburetion, or weak ignition, to name a few.

NOTE: It is good practice to drain oil at a

location away from the workbench. Be sure to allow ample time for complete drainage.

Cleaning the Engine

After inspecting the external condition of the engine, clean the engine thoroughly before disassembling it. Also clean individual components as the engine is disassembled. Only clean parts can be accurately inspected and gauged for wear or damage. There are many commercially available cleaners that will quickly remove grease, oil, and grime from engine parts. When such a cleaner is used, follow the

manufacturer’s instructions and safety precautions carefully.

Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation. Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil.

Basic Engine Tests

Crankcase Vacuum Test

A partial vacuum should be present in the crankcase when the engine is operating at normal temperatures. Pressure in the crankcase (normally caused by a clogged breather) can cause oil to be forced out at oil seals, gaskets, or other available spots.

Crankcase vacuum is best measured with water manometer or vacuum/pressure tester, see Section 2. Complete instructions are provided in the kits.

Test the crankcase vacuum, following the instructions, with the engine running at high idle speed (above 3500 RPM).

3.2

Section 3

Troubleshooting

1. The engine should have a minimum of 4 in. of vacuum. A vacuum less than 4 in. is usually due to internal wear or a bad gasket or seal allowing air to leak into the crankcase. A pressure is usually due to a problem with the breather.

Low/No Crankcase Vacuum or Pressure in Crankcase

Possible Cause

1. Crankcase breather clogged or inoperative.

2. Seals and/or gaskets leaking. Loose or improperly torqued fasteners.

3. Piston blowby or leaky valves. (Confirm by inspecting components.)

4. Restricted exhaust.

Compression T est

A compression test or a cylinder leakdown test may be performed to check the condition of an engine. Insufficient compression pressure will result in a performance loss and may indicate leaking valves or damaged/worn piston rings.

2. Refer to the following chart for possible causes and solutions.

Solution

1. Disassemble breather, clean parts thoroughly, reassemble, and recheck pressure.

2. Replace all worn or damaged seals and gaskets. Make sure all fasteners are tightened securely. Use appropriate torque values and sequences when necessary.

3. Recondition piston, rings, cylinder bore, valves, and valve guides.

4. Repair/replace restricted muffler/exhaust system.

Cylinder leakdown tester is a simple and inexpensive tester for small engines. The tester includes a quick disconnect for attaching the adapter hose and a holding tool.

Test the cylinder leakdown as follows:

Test the compression as follows:

1. Check/perform valve clearance adjustment.

2. Start engine if possible, and run for 3-5 minutes to warm it up, then stop.

3. Disconnect and ground spark plug lead. Remove the spark plug.

4. Install adapter and compression tester into spark plug hole.

5. Move the throttle control to the full/wide open position. Be sure the choke is off.

6. Crank engine over using recoil or electric starter and check results.

• Standard Compression Pressure:

400-600 kPa (57-85 psi) with ACR mechanism in operation.

Cylinder Leakdown T est

A cylinder leakdown test can be a valuable alternative to a compression test, especially on engines with ACR. By pressurizing the combustion chamber from an external air source you can determine if the valves or rings are leaking, and how badly.

1. Run engine for 3-5 minutes to warm it up.

2. Remove spark plug and air filter from engine.

3. Rotate crankshaft until piston (of cylinder being tested) is at top dead center (TDC) of the compression stroke. You will need to hold engine in this position while testing.

a. If the PTO end of the crankshaft is accessible,

the holding tool supplied with the tester can be used. Loosen the holding tool screws and expand the opening. Slide the tool onto the crankshaft as close as possible to the PTO face of the crankcase. If the slot in the tool can be aligned with one of the holes on the PTO face, find a bolt of appropriate length and thread size. Insert the bolt through the slot, and thread it into the selected hole, to prevent the tool from moving. Tighten the screws to lock the holding tool onto the crankshaft. If a PTO face hole is not accessible, tighten the screws to lock the holding tool onto the crankshaft. Insert the end of a 3/8" breaker bar into the slot, so the handle of the breaker bar is perpendicular to the crankshaft.

3.3

Section 3 Troubleshooting

b. If the flywheel end of the engine is more

accessible, you can use a breaker bar and socket on the flywheel nut/screw or a flywheel holding tool to hold it in position. When using these methods, you will need an assistant to hold it during the test.

c. If the engine is mounted in a piece of

equipment, you may be able to hold it by clamping or wedging a driven component. Just be certain the engine cannot rotate off of TDC in either direction.

4. Install the adapter into the spark plug hole, but do not attach it to the tester at this time.

5. Connect an adequate air source (70-100 psi) to the tester.

6. Turn the regulator knob in the increase (clockwise) direction until the gauge needle is in the yellow “set” area at the low end of the scale.

7. Connect tester quick-disconnect to the adapter. Note the gauge reading and listen for escaping air at the carburetor intake, exhaust outlet, and crankcase breather.

8. Check your test results against the table below:

Leakdown Test Results

Air escaping from crankcase breather ............................................... Defective rings or worn cylinder walls.

Air escaping from exhaust system ..................................................... Defective exhaust valve.

Air escaping from carburetor .............................................................. Defective intake valve.

Gauge reading in “low” (green) zone................................................ Piston rings and cylinder in good condition.

Gauge reading in “moderate” (yellow) zone.................................... Engine is still usable, but there is some wear

present. Customer should start planning for overhaul or replacement.

Gauge reading in “high” (red) zone .................................................. Rings and/or cylinder have considerable wear.

Engine should be reconditioned or replaced.

3.4

Section 4

Air Cleaner and Air Intake System

Air Cleaners

General

These engines are equipped with one of three air cleaner configurations; the standard dual-element air cleaner assembly, an optional heavy-duty cyclonic air cleaner assembly, or a third design which uses an oiled, solid foam element. The first two styles have a replaceable, high-density paper element surrounded by an oiled-foam precleaner. See Figures 4-1 and 4-2. Servicing information for these two styles is on pages

4.1 through 4.4. The third design does not use a paper element, just the foam. See Figure 4-14. Servicing information for the third design is on page 4.5. The heavy-duty air cleaner assemblies also contain a lower swirl chamber which separates the dirt particles from the incoming air for extended service intervals.

Section 4

Air Intake and Air Cleaner System

Figure 4-2. Heavy-Duty, Cyclonic Air Cleaner.

Service

Check the air cleaner daily or before starting the engine. Check for buildup of dirt and debris, along

with loose or damaged components.

Figure 4-1. Standard Dual-Element Air Cleaner.

NOTE: Operating the engine with loose or damaged

air cleaner components could allow unfiltered air into the engine causing premature wear and failure.

Figure 4-3. Removing Cover Knob Standard.

4.1

Section 4 Air Cleaner and Air Intake System

To service the precleaner perform the following steps:

1. Remove the air cleaner cover knob (standard air cleaner) or unsnap the latches (heavy-duty air cleaner), and remove the cover/housing. See Figures 4-3 and 4-4.

2. Remove the precleaner from the filter element. If element is not secured to the air cleaner base with a wing nut, remove the filter element and precleaner from the cover/housing, as an assembly before separating. See Figures 4-5 and 4-6.

Figure 4-4. Unsnapping Heavy-Duty Latches.

Figure 4-5. Standard Element/Precleaner Assembly .

3. Wash the precleaner in warm water with detergent. Rinse the precleaner thoroughly until all traces of detergent are eliminated. Squeeze out excess water (do not wring). Allow the precleaner to air dry.

4. Saturate the precleaner with new engine oil. Squeeze out all excess oil.

5. Install the precleaner over the paper element. If the element was not secured with a wing nut (some heavy-duty air cleaners) install the element/precleaner assembly, small end first, into the cover/housing.

6. Reinstall the air cleaner cover/housing assembly. Secure with the knob or latches.

Figure 4-6. Heavy-Duty Element/Precleaner Assembly .

Precleaner Service

If so equipped, wash and reoil the precleaner every 25 hours of operation (more often under extremely dusty

or dirty conditions).

4.2

Figure 4-7. Removing Standard Precleaner.

Section 4

Air Intake and Air Cleaner System

Figure 4-8. Removing Heavy-Duty Precleaner.

Figure 4-9. Removing Heavy-Duty Lower Chamber.

Figure 4-11. Inst alling Heavy-Duty Cover/Housing.

Paper Element Service

Every 100 hours of operation (more often under extremely dusty or dirty conditions), check the paper element. Replace the element as necessary. Follow these steps:

1. Standard Air Cleaner:

Loosen the air cleaner cover knob and remove the cover. Remove the wing nut and lift off the air cleaner element with precleaner. Remove the precleaner from the paper element. Service the precleaner.

Heavy-Duty, Cyclonic Air Cleaner:

Unhook the latches and remove the housing assembly from the mounting base. Remove the wing nut (some models) securing air cleaner/ precleaner assembly, or pull the complete filter assembly out of the housing. Remove the precleaner from the paper element. Service the precleaner.

2. Do not wash the paper element or use pressurized air, as this will damage the element. Replace a dirty, bent, or damaged element with a genuine Kohler element. Handle new elements carefully; do not use if the sealing surfaces are bent or damaged.

Figure 4-10.

4.3

Section 4 Air Cleaner and Air Intake System

3. When servicing the air cleaner, check the air cleaner base, and cover/housing assembly. Make sure it is secure and not bent or damaged. On a heavy-duty air cleaner, unsnap the latches and clean out the lower swirl/dirt chamber. See Figure 4-9. Make sure the air slots in the upper section of the housing and in the lower chamber are open. See Figure 4-10. Clean and inspect all components for damage or improper fit. Replace any components which are bent or damaged. Reassemble the lower chamber (heavy duty air cleaners).

NOTE: Before the air cleaner is reassembled make

sure the rubber seal is in position on the stud (standard only). Also inspect the foam seal on the base of the filter element, do not use if the condition of either is questionable in any way. Replace it with a new part before reassembling.

4. Standard Air Cleaner: Install the serviced precleaner over the element. Position the element/precleaner assembly on the base and secure with the wing nut. Reinstall the air cleaner cover and tighten securely. See Figure 4-5.

Heavy-Duty Cyclonic Air Cleaner

Make sure the main housing, lower swirl/dirt chamber, mounting hardware and latches are not damaged, bent or broken; affecting the sealing ability and operation of air cleaner housing. Clean and check all components as well as the airflow passages.

Air Cleaner Base

Make sure the air cleaner base is secured tightly to carburetor and not cracked, bent or damaged, preventing a proper seal.

Breather T ube

Make sure the breather tube is in good condition and connected to the air cleaner base or adapter and the breather cover. Replace the tube if it is cracked or damaged.

Heavy-Duty Cyclonic Cleaner:

Place the precleaner over the element and install it as an assembly into the cover/housing. Insert the small end first, into the housing, so the larger end with the foam seal is out (visible). Secure with the wing nut (if used). Secure the cover/ housing with the latches. See Figure 4-11.

Air Cleaner Components

Whenever the air cleaner cover is removed, or the paper element or precleaner is serviced, check the following:

Standard Air Cleaner

Make sure the element cover is not bent, distorted or damaged. Make sure the wing nut and rubber sleeve seal on the base stud are in place and in good condition, ensuring the element is sealed against leakage. (Some models the seal is fixed).

If the air cleaner element has a foam seal on the bottom, make sure it is in good condition and not damaged. See Figure 4-12.

Figure 4-12. Foam Seal.

Figure 4-13. Cutaway View .

4.4

Section 4

Air Intake and Air Cleaner System

CS8.5 (spec. 95xxxx) engines use an air cleaner base with a serviceable rubber base pad to seal the air filter element on the bottom. See Figure 4-14. Make sure the pad is installed, clean, and in good condition.

Figure 4-14. Serviceable Rubber Base Pad.

Foam Air Cleaner Element

To service the foam element perform the following steps:

1. Remove the two screws and the outer air cleaner cover/housing. See Figure 4-16.

Mounting Screw

Figure 4-16. Mounting Details.

2. Remove the foam element from the air cleaner housing. See Figure 4-17.

Figure 4-15. Foam Air Cleaner Configuration.

Check the air cleaner daily or before starting the engine. Check for buildup of dirt and debris, along with loose or damaged components.

NOTE: Operating the engine with loose or damaged

air cleaner components could allow unfiltered air into the engine causing premature wear and failure.

Every 50 hours of operation, wash and reoil the foam air cleaner element (more often under extremely dusty, or dirty conditions). Replace the foam element with a new genuine Kohler element if deteriorated or damaged in any way.

Foam Air Cleaner Element

Figure 4-17. Foam Air Cleaner Element Det ails.

3. Wash the foam element in warm water with detergent. Rinse the element thoroughly until all traces of detergent are eliminated. Squeeze out all excess water (do not wring). Allow the element to air dry.

4. Lightly oil the element with new engine oil. Squeeze element to evenly distribute the oil and remove any excess.

4.5

Section 4 Air Cleaner and Air Intake System

5. When servicing the foam air cleaner element, clean and check the air cleaner case and outer cover for damage, distortion, or an improper seal. Replace any components which are bent or damaged.

6. Make sure the square metal fitting plate is properly positioned within the case. See Figure 4-17.

7. Reinstall the outer cover and secure with the two screws. See Figure 4-16.

NOTE: Do not operate engine without the air cleaner

element; excessive piston and/or cylinder wear may result.

Air Intake/Cooling System

To ensure proper cooling, make sure the grass screen, cooling fins and other external surfaces of the engine are kept clean at all times.

Every 100 hours of operation (more often under extremely dusty or dirty conditions), remove the blower housing and other cooling shrouds. Clean the cooling fins and external surfaces as necessary. Make sure the cooling shrouds are reinstalled.

NOTE: Operating the engine with a blocked grass

screen, dirty or plugged cooling fins, and/or cooling shrouds removed, will cause engine damage due to overheating.

4.6

Fuel System and Governor

Section 5

Fuel System and Governor

Section 5

Description

WARNING: Explosive Fuel!

Fuel System Components

The typical fuel system includes the following components:

• Fuel Tank

• Shut-off Valve with Screen Filter

• Fuel Tank Inlet Filter

• Carburetor

• Fuel Line

Operation

The fuel from the tank is moved through the shut-off valve/screen filter and fuel lines by gravity.

• Do not use gasoline left over from the previous season, to minimize gum deposits in your fuel system and to insure easy starting.

• Do not add oil to the gasoline.

• Do not overfill the fuel tank. Leave room for the fuel to expand.

Fuel T yp e

For best results, use only clean, fresh, unleaded gasoline with a pump sticker octane rating of 87 or higher. In countries using the Research fuel rating method, it should be 90 octane minimum.

Unleaded gasoline is recommended, as it leaves less combustion chamber deposits. Leaded gasoline may be used in areas where unleaded is not available and exhaust emissions are not regulated.

Gasoline/Alcohol blends

Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) is approved as a fuel for Kohler engines. Other gasoline/alcohol blends are not approved.

Fuel then enters the carburetor float bowl and is drawn into the carburetor throat. There, the fuel is mixed with air. This fuel-air mixture is then burned in the engine combustion chamber.

Fuel Recommendations

General Recommendations

Gasoline/Ether blends

Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved as a fuel for Kohler engines. Other gasoline/ether blends are not approved.

Fuel Filters

Serviceable screen filters are located within the inlet of the fuel tank and the shut-off valve. Periodically inspect and clean or replace as required.

5.1

Section 5 Fuel System and Governor

Fuel Line

In compliance with CARB Tier III Emission Regulations, engines with a “Family” identification number beginning with “6” or greater (see Figure 5-1), must use Low Permeation SAE 30 R7 rated fuel line; certified to meet CARB requirements. Standard fuel line may not be used. Order replacement hose by part number through a Kohler Engine Service Dealer.

Fuel System Tests

When the engine starts hard, or turns over but will not start, it is possible that the problem is in the fuel system. To find out if the fuel system is causing the problem, perform the following tests.

IMPORTA NT ENGINE INFORMATION THIS ENGINE MEETS U.S. EPA PHASE II, 2002-

2005 CALIFORNIA AND EC STAGE II (SN:4) EMISSION CONTROL REGS FOR SI SMALL OFF– ROAD ENGINES

F AMILY 6 YYMXS.1171 EA TYPE APP

MODEL NO. SPEC. NO. DISPL. (CC) SERIAL NO. OEM PROD. NO.

EMISSION COMPLIANCE PERIOD: EPA: CATEGORY A CERTIFIED ON: UNLEADED GASOLINE

REFER TO OWNER'S MANUAL FOR SAFETY, MAINTENANCE SPECS, AND ADJUSTMENTS

1-800-544-2444 www.kohlerengines.com

KOHLER CO. KOHLER, WISCONSIN USA

(REF:_______________ )

Troubleshooting – Fuel System Related Causes

1. Check the following:

a. Make sure the fuel tank contains clean, fresh,

proper fuel. b. Make sure the vent in the fuel cap is open. c. Make sure the fuel valve is open.

2. Check for fuel in the combustion chamber.

a. Disconnect and ground the spark plug lead. b. Close the choke on the carburetor. c. Crank the engine several times. d. Remove the spark plug and check for fuel at

the tip.

3. Check for fuel flow from the tank to the

carburetor.

a. Remove the fuel line from the inlet fitting of

the carburetor. b. Hold the line below the bottom of the tank.

Open the shut-off valve and observe flow.

N432

Figure 5-1. “Family” Number Location.

ConclusionTest

2. If there is fuel at the tip of the spark plug, fuel is

reaching the combustion chamber.

If there is no fuel at the tip of the spark plug, check for fuel flow from the fuel tank. (Test 3)

3. If fuel does flow from the line, check for a

problem in the carburetor (dirt, gum, varnish, etc.).

If fuel does not flow from the line, check for a clogged fuel cap vent, inlet filter, shut-off valve screen filter, and/or fuel line(s).

Carburetor

General

The CS engines use fixed jet MIKUNI carburetors. The fixed main jet carburetor is designed to deliver the correct fuel-to-air mixture to the engine under all

5.2

operating conditions. The high idle mixture is set at the factory and cannot be adjusted. The low fuel adjusting needle is also set at the factory and normally does not need adjustment.

NOTE: Carburetor adjustments should be made only

after the engine has warmed up.

Condition

1. Engine starts hard, runs roughly or stalls at idle speed.

Section 5

Fuel System and Governor

Troubleshooting – Carburetor Related Causes

Possible Cause/Probable Remedy

1. Low idle fuel mixture/speed improperly adjusted. Adjust the low idle speed RPM, then adjust the low idle fuel needle.

2. Engine runs rich. (Indicated by black, sooty exhaust smoke, misfiring, loss of speed and power, governor hunting, or excessive throttle opening.)

3. Engine runs lean. (Indicated by misfiring, loss of speed and power, governor hunting, or excessive throttle opening.)

4. Fuel leaks from carburetor.

2a. Clogged air cleaner. Clean or replace. b. Choke partially closed during operation. Check the choke lever/linkage

to ensure choke is operating properly.

c. Low idle fuel mixture is improperly adjusted. Adjust low idle fuel

needle.

d. Float level is too high. Separate carburetor bowl from carburetor body,

check float setting against specification. Replace float if required.

e. Dirt under the fuel inlet needle. Remove needle; clean needle and seat

and blow out with compressed air.

f. Bowl vent pilot jet or air bleeds plugged. Remove low idle fuel adjusting

needle. Clean vent, ports, and air bleeds. Blow out all passages with compressed air.

g. Leaky, cracked, or damaged float. Submerge float to check for leaks.

3a. Low idle fuel mixture is improperly adjusted. Adjust low idle fuel

needle.

b. Float level is too low. Separate carburetor bowl from carburetor body,

check float setting against specification. Replace float if required.

c. Idle holes plugged; dirt in fuel delivery channels. Remove low idle fuel

adjusting needle. Clean main fuel jet and all passages; blow out with compressed air.

4a. Float level too high. See Remedy 2d. b. Dirt under fuel inlet needle. See Remedy 2e. c. Bowl vent plugged. Blow out with compressed air. d. Carburetor bowl gasket leaks. Replace gasket.

Troubleshooting Checklist

If engine troubles are experienced that appear to be fuel system related, check the following areas before adjusting or disassembling the carburetor.

• Make sure the fuel tank is filled with clean, fresh gasoline.

• Make sure the fuel cap vent and inlet filter are not blocked and operating properly.

• Make sure fuel is reaching the carburetor. This includes checking the fuel shut-off valve, screen filters, and fuel lines for restrictions.

• Make sure the air cleaner base and carburetor are securely fastened to the engine using gaskets in good condition.

• Make sure the air cleaner element is clean and all air cleaner components are fastened securely.

• Make sure the ignition system, governor system, exhaust system, and throttle and choke controls are operating properly.

If, after checking all items listed above, the engine is hard to start, runs roughly, or stalls at low idle speed, it may be necessary to adjust or service the carburetor.

5.3

Section 5 Fuel System and Governor

Adjustments

General

NOTE: Carburetor adjustments should be made only

after the engine has warmed up.

The carburetor is designed to deliver the correct fuelto-air mixture to the engine under all operating conditions. The high idle mixture is set at the factory and cannot be adjusted. The low idle fuel adjusting needle is also set at the factory and has a limiting cap. It normally does not need adjustment.

Adjusting Low Idle Fuel and Speed

NOTE: Certified engines have a limiter cap on the

idle fuel adjusting needle. Adjustment can only be performed within the limits allowed by the cap.

1. Start engine and run at half throttle for 5 to 10 minutes to warm up. The engine must be warm before making final settings.

2. Low Idle Fuel Needle Setting: Place the throttle into the ‘‘idle’’ or ‘‘slow’’ position. Turn the low idle fuel adjusting needle in or out within the adjustment range, to obtain the best low speed performance.

3. Low Idle Speed Setting: Place the throttle control into the ‘‘idle’’ or ‘‘slow’’ position. Set the low idle speed to 2000 RPM* (± 150 RPM) by turning the low idle speed adjusting screw in or out. Check the speed using a tachometer.

*NOTE: The actual low idle speed depends on

the application – refer to equipment manufacturer's recommendations. The recommended low idle speed for basic engines is 2000 RPM. To ensure best results when setting the low idle fuel needle, the low idle speed must not exceed 2000 RPM (± 150 RPM).

Idle Speed Screw

Idle Fuel Needle with Limiter Cap

Figure 5-2. Carburetor Adjustment s.

5.4

Section 5

Fuel System and Governor

1. Pilot Jet

2. Screw

3. Main Jet

4. Main Nozzle

5. Float

6. Float Pin

7. Float Gasket

8. Drain Plug

9. Spring

10. Washer

Figure 5-3. CS4 and CS6 Carburetor - Exploded View.

11. Bowl Retaining Screw

12. Float Bowl

13. Clip

14. Needle Assembly

15. Spring

16. Idle Fuel Adjusting Screw

17. Limiter Cap

18. Screw

1. Pilot Jet

2. Plug Screw Washer

3. Seal

4. Main Jet

5. Screw

6. Main Nozzle

7. Main Pipe

8. Float

9. Float Gasket

10. Drain Plug

11. Gasket

12. Bowl Retaining Screw

Figure 5-4. CS8.5-12 Carburetor - Exploded View.

13. Float Pin

14. Clip

15. Needle Assembly

16. Spring

17. Throttle Adjusting Screw

18. Spring

19. Idle Fuel Adjusting Screw

20. Limiter Cap

21. Screw

22. Ball

5.5

Section 5 Fuel System and Governor

Carburetor Service

If symptoms described in the carburetor troubleshooting guide indicate a problem within the carburetor, the following steps can be used to remove the carburetor from the engine and provide the necessary service.

1. Remove the air cleaner cover, wing nut, filter element with precleaner, the air cleaner base mounting screws and hex flange nuts from the mounting bracket(s) and main mounting studs.

2. Disconnect the breather hose from the valve cover or air cleaner base, and remove the base from the engine.

3. Disconnect the fuel line from the carburetor inlet.

4. Disconnect the choke link and spring at the carburetor end (CS8.5-12 only).

Figure 5-5. Float Height Position.

5. Slide the carburetor off of the mounting studs while disconnecting the throttle link and dampening spring.

6. Clean all dirt and debris from exterior of carburetor.

7. Remove the screw from the bottom center of carburetor bowl. Carefully separate the bowl from the main body and remove the bowl gasket from the body.

8. Place the carburetor in an inverted position. Lift up the float so that the tip of the float valve lightly contacts the float arm. See Figure 5-5. Measure the float height from the casting surface as illustrated in Figure 5-6. Float height for the CS4 and CS6 is 16 mm (0.63 in.). Float height for the CS8.5, CS10, and CS12 is 14.9 mm (0.59 in.). Install a float kit if the float height is incorrect.

Float Kit Contains:

Qty

1 1 1 1 2 1

Description

Float Gasket, bowl Gasket, bowl screw Pin, float Gasket, intake Gasket, air cleaner base

Figure 5-6. Measuring Float Height.

CAUTION

Do not bend the float in an attempt to reset the height. The correct float height is determined by the design of the inlet needle and float. There is no provision for physical adjustment.

9. Check to see if the fuel inlet needle or seat is dirty, obstructed or worn.

a. Remove the main jet from the side of the

tower.

b. Grab the exposed end of the float pin with a

needle nose pliers and pull it out.

c. Lift out the float and inlet needle. Slide the

inlet needle and clip off of the float tab.

d. Check components for contamination, wear,

or damage. See Figure 5-7. Use carburetor cleaner to clean out any dirt or contamination. Use a float kit if the inlet needle or float is damaged or worn. If the inlet seat is damaged or worn, the carburetor must be replaced.

5.6

Section 5

Fuel System and Governor

Grooved Wear

Dust

Figure 5-7. Inlet Needle and Seat Wear/Damage Details.

10. After the parts have been cleaned or exchanged, slide the inlet needle onto the float tab, reinstall the float assembly into the carburetor, and verify that the correct float height has been restored.

11. If there were gum or varnish deposits in the area of the inlet needle and seat, there is a good possibility that the main nozzle may also need cleaning before the bowl is reinstalled. The main nozzle is threaded into the tower and can be removed for cleaning, but be careful not to damage it, as it is not available as a service part.

Governor

These engines are equipped with a centrifugal flyweight mechanical governor. The governor is designed to hold the engine speed constant under changing load conditions. The governor gear/ flyweight mechanism is mounted inside the crankcase and driven off the gear on the crankshaft.

Operation

Centrifugal force acting on the rotating governor gear assembly causes the flyweights to move outward as speed increases. See Figure 5-8. As the flyweights move outward, they cause the regulating pin to extend from the governor gear assembly.

Speed Increasing

Speed Decreasing

a. Use a thin, flat blade screwdriver to remove

the nozzle from the tower. If it does not turn easily, use some carburetor cleaner to clean the exposed threads in the tower.

b. Soak the nozzle in carburetor cleaner to

remove any deposits and blow it dry with compressed air.

c. Reinstall it in the tower and thread it in until

it bottoms.

12. Reinstall the main jet and install the bowl gasket in the groove. Reassemble the bowl to the carburetor with the screw removed in step 7. Position the bowl so the drain screw will be accessible after the carburetor is mounted to the engine.

13. Use the reverse of steps 1-5 to reinstall the carburetor on the engine.

Figure 5-8. Action of Governor Gear.

The regulating pin contacts the tab on the cross shaft, causing the shaft to rotate when the engine speed changes. See Figure 5-9. One end of the cross shaft protrudes through the side of the closure plate. Through external linkage attached to the cross shaft, the rotating action is transmitted to the throttle lever of the carburetor.

When the engine is at rest, and the throttle control is in the ‘‘fast’’ position, the tension of the governor spring holds the throttle plate open. When the engine is operating (the governor gear assembly is rotating), the force applied by the regulating pin against the cross shaft tends to close the throttle plate. The governor spring tension and the force applied by the regulating pin are in ‘‘equilibrium’’ during operation, holding the engine speed constant.

5.7

Section 5 Fuel System and Governor

When a load is applied and the engine speed (and governor gear speed) decreases, the governor spring tension moves the governor lever to open the throttle plate wider. This allows more fuel into the engine, increasing engine speed. (This action occurs very rapidly, so a reduction in speed is hardly noticed.) As the speed reaches the governed setting, the governor spring tension and the force applied by the regulating pin will again be in equilibrium. This maintains the engine speed at a relatively constant level.

The governed speed setting is determined by the position of the throttle control. It can be variable or constant, depending on the application.

6. Hold both in this position and tighten the governor lever bolt.

Torque the bolt to:

8 N·m (70.8 in. lb.) on CS4, CS6 10 N·m (88.5 in. lb.) on CS8.5, CS10, CS12

Governor Shaft

Governor Lever

Mounting Bolt

Figure 5-10. CS4, CS6 Governor Adjustment.

Governor Shaft

Figure 5-9. Governor System.

Initial Adjustment

Make this initial adjustment whenever the governor lever is loosened or removed from the cross shaft. To ensure proper setting, make sure the throttle linkage is connected to the governor lever and to the carburetor throttle lever (certain engine components removed for clarity of illustration).

Governor Adjustment

1. Close the fuel shut-off valve.

2. Remove the air cleaner outer cover. Then either reposition the fuel tank to access governor shaft and lever joint, or disconnect the fuel line and remove the tank from the engine.

NOTE: Make sure the carburetor is mounted

and secured in place when adjustment is being made/checked.

3. Loosen the governor lever mounting bolt.

4. Move the governor lever clockwise until it stops.

5. Rotate the governor shaft clockwise until it stops.

Mounting Bolt

Figure 5-11. CS8.5 (spec. 92xxxx), CS10, and CS12 Governor Adjustment.

Figure 5-12. CS8.5 (spec. 95xxxx) Governor Adjustment.

Governor Lever

5.8

High Idle Speed Adjustment

The recommended maximum no-load high idle speed for the CS engines is 3750 RPM (± 100 RPM) for tapered shaft models, and 3800 RPM (± 100 RPM) for all others. The actual high idle speed depends on the application. Refer to the equipment manufacturer's instructions for specific information.

The high idle speed is set by turning the throttle stop screw on the throttle lever bracket assembly in or out. See Figures 5-13 to 5-15 and follow the procedures below.

Section 5

Fuel System and Governor

1. Start the engine and allow it to warm up. Place the throttle control lever into the ‘‘fast’’ or high idle position.

2. Check the engine speed with a tachometer.

3. To increase the high idle speed–turn the high idle speed adjusting screw out (counterclockwise), while applying light pressure to the throttle control lever in the counterclockwise direction (away from the carburetor).

To decrease the high idle speed–turn the high idle speed adjusting screw in (clockwise), until the desired engine speed is attained.

Throttle Stop Screw Throttle Lever

Figure 5-14. CS8.5 (spec. 92xxxx), CS10, and CS12 Throttle Lever/Throttle Stop Screw Details.

Throttle Stop Screw

Throttle Lever

Figure 5-15. CS8.5 (spec. 95xxxx) Throttle Lever/ Throttle Stop Screw Details.

Throttle Stop Screw

Figure 5-13. CS4, CS6 Throttle Lever/Throttle Stop Screw Details.

Throttle Lever

5.9

Section 5 Fuel System and Governor

Low Idle Speed Adjustment

The recommended low idle speed is 2000 RPM (± 100 RPM). The low idle speed is set by turning the low idle speed screw in or out, see Figures 5-16 and 5-17.

1. With the engine warm, move the throttle lever clockwise until it stops.

2. Check the idle speed with a tachometer.

3. Turn the adjustment screw in (clockwise) to increase the idle speed, or out (counterclockwise) to decrease the idle speed, until the correct speed is attained.

Adjusting Screw

Figure 5-17. CS8.5-12 Low Idle Speed Adjusting Screw.

Adjusting Screw

Figure 5-16. CS4, CS6 Low Idle Speed Adjusting Screw.

5.10

Section 6

Lubrication System

General

These engine use a splash lubrication system, supplying necessary lubrication to the crankshaft, camshaft, connecting rod and valve train components.

Oil Recommendations

Using the proper type and weight of oil in the crankcase is extremely important. So is checking oil daily and changing oil regularly. Failure to use the correct oil or using dirty oil can cause premature engine wear and failure.

Oil T ype

Use high quality detergent oil of API (American Petroleum Institute) service class SG, SH, SJ or higher. Select the viscosity based on the air

temperature at the time of operation as shown in the following table.

Section 6

Lubrication System

Figure 6-1. Oil Container Logo.

Check Oil Level

The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized. Check oil BEFORE EACH USE as follows:

Synthetic oils should not be used.

NOTE: Using other than service class SG, SH, SJ or

higher oil or extending oil change intervals longer than recommended can cause engine damage.

A logo or symbol on oil containers identifies the API service class and SAE viscosity grade. See Figure 6-1.

1. Make sure the engine is stopped, level, and is cool so the oil has had time to drain into the sump.

2. Clean the area around the oil fill cap to keep dirt, debris, etc., out of the engine.

3. Unthread and remove the oil fill cap.

4. The oil level should be at the point of overflowing out of the filler neck. See Figure 6-2.

6.1

Section 6 Lubrication System

Bring Level Up To Point of Overflow

Proper

Oil Level

Low Oil

Level

NOTE: If the engine stalls or does not start, turn the

engine switch to the ‘‘on’’ position and attempt to start the engine. If the oil warning light flickers for a few seconds, the engine oil is insufficient. Add oil and restart.

NOTE: Make sure the oil level is checked BEFORE

EACH USE and is maintained up to the point of overflowing the filter neck.

Figure 6-2. Cutaway Showing Proper Oil Level.

5. If the level is low add oil of the proper type to bring the level up to the point of overflowing.

NOTE: To prevent extensive engine wear or damage,

always maintain the proper oil level in the crankcase. Never operate the engine with the oil below the low oil level.

NOTE: Just because you can see oil in the crankcase

doesn't mean the level is in the safe range. Bring the level up to the point of overflowing the filler neck.

Oil Sentry™

Some engines are equipped with an Oil Sentry™ oil monitor. When the oil level falls below the safe level, the engine stops automatically. Unless you refill with oil, the engine will not start again. See Figure 6-3.

Change Oil

For a new engine, change oil after the first 20 hours of operation. Thereafter, change oil after every 100 hours of operation.

For an overhauled engine, use 10W-30 weight service class SG, SH, SJ or higher oil for the first 5 hours of operation. Change the oil after this initial run-in period. Refill with service class SG, SH, SJ or higher oil as specified in the “Viscosity Grades” table on page 6.1.

Change the oil while the engine is still warm. The oil will flow more freely and carry away more impurities. Make sure the engine is level when filling, checking, and changing the oil.

Change the oil as follows:

1. To keep dirt and debris out of the engine, clean the area around the oil fill/check plug before removing it.

2. Remove the oil drain plug and oil fill/check plug. Be sure to allow ample time for complete drainage.

Figure 6-3. Oil Sentry™ Operation.

6.2

3. Reinstall the drain plug. Make sure it is tightened to 17.6 N·m (13 ft. lb.) torque.

4. Fill the crankcase, with new oil of the proper type, up to the point of overflowing the filler neck. Refer to ‘‘Oil Type’’ on page 6.1. Always check the level before adding more oil.

5. Reinstall the oil fill/check plug and tighten securely.

NOTE: To prevent extensive engine wear or damage,

always maintain the proper oil level in the crankcase. Never operate the engine with the oil level below the low oil level.

Figure 6-4. CS4, CS6 Right Oil Fill/Level Plug Location.

Section 6

Lubrication System

Figure 6-6. CS8.5-12 Right Oil Fill/Level Plug Location.

Figure 6-5. CS4, CS6 Left Oil Fill/Level Plug Location.

Figure 6-7. CS8.5-12 Left Oil Fill/Level Plug Location.

6.3

Section 7

Retractable Starter

Section 7

Retractable Starter

WARNING: S pring Under Tension!

Pawl Repair

Starter Handle

Starter Rope

Kit

Drive Cup

Center Screw

Drive Plate Friction Spring Drive Pawl

Spring

Starter Housing

Figure 7-1. Retractable St arter - Exploded V iew.

To Remove Starter

1. Remove the hex flange screws (three on CS4 and CS6, four on CS8.5-12) securing the starter assembly to the blower housing.

2. Remove the starter assembly.

To Install Starter

1. Align the retractable starter with the mounting locations on the blower housing, and install the hex flange screws. Leave the screws slightly loose.

Pulley

Recoil Spring

Figure 7-2. Installing Retractable St arter.

7.1

Section 7 Retractable Starter

2. Pull the starter handle out until the pawls engage the drive cup. Hold the handle in this position and torque the screws to 5.5 N·m (48 in. lb.). See Figure 7-3.

Figure 7-3. Engage Pawls and Tighten Mounting Screws.

Rope Replacement

The rope can be replaced without complete starter disassembly.

5. When all spring tension on the starter pulley is released, remove the rope from the pulley.

6. Tie a single knot in one end of the new rope.

7. Rotate the pulley counterclockwise to pre-tension the spring (approximately 4 full turns of pulley on CS4 and CS6; approximately 5 full turns of pulley on CS8.5-12).

8. Rotate the pulley until the rope hole in pulley is aligned with the rope guide bushing of the starter housing.

NOTE: Do not allow the pulley/spring to

unwind. Enlist the aid of a helper if necessary.

9. Feed the unknotted end of the rope through the rope hole in the starter pulley and rope guide bushing of the housing. See Figure 7-5.

1. Remove the starter from the engine blower housing.

2. Pull the rope out approximately 12" and tie a temporary (slip) knot in it to keep it from retracting into the starter. See Figure 7-4.

Figure 7-4. Removing Starter Handle.

3. Pull the knot end out of the handle, untie the knot, and slide the handle off.

Figure 7-5. Installing Rope.

10. Tie a slip knot approximately 12" from the free end of rope. Hold the pulley firmly and allow it to rotate slowly until the slip knot reaches the guide bushing of the housing.

11. Slip the handle onto the rope. Tie a single knot at the end of the rope.

12. Untie the slip knot and pull on the handle until the rope is fully extended. Slowly retract the rope into the starter. If the spring is properly tensioned, the rope will retract fully and the handle will stop against the starter housing.

4. Hold the pulley firmly and untie the slip knot. Allow the pulley to rotate slowly as the spring tension is released.

7.2

Section 7

Retractable Starter

Pawl (Dogs) Replacement

Only partial disassembly of the starter is necessary to replace the pawls. Pawl repair kits are available which include the following components:

CS4 and CS6 Pawl Repair Kit Contains

Qty

1 1 2

CS8.5-12 Pawl Repair Kit Contains

Qty

1 2 1 2

Description

Drive Plate Center Screw Clip Starter Pawl (Dog)

Description

Drive Plate Center Screw Pawl (Dog) Spring Clip Starter Pawl (Dog)

Disassembly

WARNING: S pring Under Tension!

Do not remove the center screw from starter until the spring tension is released. Removing the center screw before releasing spring tension, or improper starter disassembly, can cause the sudden and potentially dangerous release of the spring. Follow these instructions carefully to ensure personal safety and proper starter disassembly. Make sure adequate face protection is worn by all persons in the area.

1. Release recoil spring tension by:

CS4, CS6: Loosen the center screw approximately 1 turn. Rotate the pulley against spring tension

until the pulley rope hole with knot is adjacent to outlet in housing. Lift up the slack in rope between pulley and housing, slowly allow the pulley to unwind, releasing the spring tension. Count the number of rotations for reassembly later.

2. Unscrew the center screw and lift off the drive plate. The center screw will be captured by the clip around the shoulder on backside of plate.

3. Note the positions of the pawls and pawl springs (CS8.5-12 only) before removing. Remove parts from pulley.

4. Carefully inspect the components for wear, cracks, and/or damage. Replace all worn or damaged components. Use only genuine Kohler replacement parts as specified in the parts manuals. All components shown in Figure 7-1 are available as service parts. Do not use nonstandard parts.

5. Install pawl springs (CS8.5-12 only) and pawls onto pawl studs of pulley. All parts must be dry.

Pawl

Pawl Spring

Figure 7-6.

6. Position the drive plate over the pawls, aligning the actuating slots in the plate with the raised sections on each drive pawl. Torque the center screw to 5-6 N·m (44-53 in. lb.). Rotate the pulley by hand and check operation. See Figure 7-7.

CS8.5-12: Rotate the pulley against spring tension, until the cutout in pulley is adjacent to outlet in housing. Lift up the slack in rope through the cutout and slowly allow pulley to unwind, releasing spring tension. Count the number of rotations for reassembly later.

7.3

Section 7 Retractable Starter

Clip

Drive Plate

Figure 7-7. Drive Plate and Pawl Details.

7. Rehook the slack in rope into notch of pulley and rotate the pulley counterclockwise (viewed from pawl side) to re-tension the spring (approximately 4 full turns on CS4 and CS6; approximately 5 full turns on CS8.5-12).

Recoil Spring, Pulley, and/or Housing Replacement

Disassembly

1. Release spring tension and remove the handle and starter rope. (Refer to ‘‘Rope Replacement’’.)

2. Unscrew the center screw and lift off the drive plate. The screw will be captured within plate by the clip on backside.

3. Carefully note the positions of the pawls and pawl springs (CS8.5-12 only) before removing them. Remove the parts from the starter pulley.

4. Rotate the pulley clockwise (1/2 to 1 full turn) this will ensure the spring is disengaged from the starter housing.

5. Carefully lift the pulley out of the recoil housing, while reaching through the spokes of the pulley to keep the spring from coming out of the pulley.

6. Wearing adequate eye/face protection, carefully remove the spring from the pulley cavity.

7. Clean all parts including the starter spring cavity in pulley and recoil housing of all old grease and dirt. Inspect all parts for wear or damage and replace as required.

Figure 7-8. Retractable St arter Pawl Assembly Details.

WARNING: S pring Under Tension!

7.4

Figure 7-9. Disassembled Retractable St arter .

Reassembly

1. Generously lubricate the recoil spring with a commercially available bearing grease.

2. Engage the outer spring hook into the pulley ‘‘slit’’ opening, then carefully wind the spring counterclockwise into the drum of the pulley from larger to smaller diameter.

3. Carefully install pulley into recoil housing, engaging the spring hook with starter housing tab. See Figure 7-10.

NOTE: Rotating pulley counterclockwise

slightly will assist engagement.

4. Install the pawl springs (CS8.5-12 only) and pawls onto pawl studs of pulley.

Section 7

Retractable Starter

Figure 7-11. Torque Center Mounting Screw.

6. Tension the spring and install the rope and handle as outlined in Steps 6 through 12 under ‘‘Rope Replacement.’’

7. Install the recoil starter to engine blower housing but do not fully tighten the mounting screws.

Figure 7-10. Assembling St arter Pulley to Housing.

5. Mount drive plate over pawls onto pulley, aligning the actuating slots in plate with the raised sections on each drive pawl. Torque the screw to 5-6 N·m (44-53 in. lb.). Rotate the pulley by hand and check operation. See Figure 7-11.

8. Pull out on recoil handle/rope to engage the pawls to the drive cup, hold engaged and torque the mounting screws to 5.5 N·m (47.7 in. lb.). See Figure 7-3.

7.5

Section 8

Electrical System and Components

Section 8

Electrical System and Components

This section covers the operation, service, and repair of the electrical systems and electrical system components.

Spark Plug

Engine misfire or starting problems are often caused by a spark plug that is in poor condition or has an improper gap setting.

This engine uses the following spark plugs:

Type: The original spark plug is an NGK

BPR4ES1. The Champion® equivalent of that NGK spark plug is RN14YC2. The service replacement is Champion® RC14YC3 (Kohler Part No. 66 132 01-S). Equivalent alternate brand spark plugs can also be used.

Gap: 0.76 mm (0.030 in.) Thread Size: 14 mm Reach: 19.1 mm (3/4 in.) Hex Size:

1,2

20.6 mm (13/16 in.)

15.9 mm (5/8 in.)

NOTE: Do not clean the spark plug in a machine

which uses abrasive grit. Some grit could remain on/in the spark plug and enter the engine, causing extensive wear and damage.

3. Check the gap using a wire feeler gauge. Adjust the gap to 0.76 mm (0.030 in.) by carefully bending the ground electrode. See Figure 8-1.

4. Reinstall the spark plug into the cylinder head. Torque the spark plug to 20 N·m (177 in. lb.).

Wire Gauge

Spark Plug

Spark Plug Service

Every 100 hours of operation, remove the spark plug, check its condition and reset the gap, or replace it with a new plug as necessary.

1. Before removing the spark plug, clean the area around the base of the plug to keep dirt and debris out of the engine.

2. Remove the plug and check its condition. Replace the plug if worn or reuse is questionable.

Ground Electrode

Figure 8-1. Servicing Spark Plug.

0.76 mm

(0.030 in.) Gap

8.1

Section 8 Electrical System and Components

Inspection

Inspect the spark plug as soon as it is removed from the cylinder head. The deposits on the tip are an indication of the general condition of the piston rings, valves, and carburetor.

Normal and fouled plugs are shown in the following photos.

Worn: On a worn plug, the center electrode will be rounded and the gap will be greater than the specified gap. Replace a worn spark plug immediately.

Normal: A plug taken from an engine operating under normal conditions will have light tan or gray colored deposits. If the center electrode is not worn, a plug in this condition could be set to the proper gap and reused.

Carbon Fouled: Soft, sooty, black deposits indicate incomplete combustion caused by a restricted air cleaner, overrich carburetion, weak ignition, or poor compression.

Wet Fouled: A wet plug is caused by excess fuel or oil in the combustion chamber. Excess fuel could be caused by a restricted air cleaner, a carburetor problem, or operating the engine with too much choke. Oil in the combustion chamber is usually caused by a restricted air cleaner, a breather problem, or internal engine wear.

8.2

Section 8

Electrical System and Components

Operation

As the flywheel rotates and the magnet assembly moves past the ignition module, a low voltage is induced in the primary windings of the module. When the primary voltage is precisely at its peak, the module induces a high voltage in its secondary windings. This high voltage creates a spark at the tip of the spark plug. This spark ignites the air-fuel mixture in the combustion chamber.

The timing of the spark is automatically controlled by the module. Therefore, other than periodically checking/replacing the spark plug, no maintenance, timing, or adjustments are necessary or possible with this system.

Overheated: Chalky, white deposits indicate very high combustion temperatures. This condition is usually accompanied by excessive gap erosion. Lean carburetor settings, an intake air leak, or incorrect spark timing are normal causes for high combustion temperatures.

Electronic TCI (Transistor Controlled Ignition) System

These engines are equipped with a dependable electronic TCI system providing:

• Maintenance free operation.

• Strong spark output.

• Stable, controlled ignition timing.

The system consists of the following components:

• A magnet assembly which is permanently affixed to the flywheel.

• A TCI module which mounts on the engine crankcase.

• An engine stop switch which grounds the module to stop the engine.

• A spark plug.

Electric Start Engines also contain:

• An electric starter motor.

• A 3-position starter switch.

• A starter solenoid.

• Wiring harness with fuse.

• Rectifier-Regulator.

In the event starting problems should occur which are not corrected by replacing the spark plug, refer to the ‘‘Troubleshooting Guide’’ for trouble analysis procedures.

Oil Sentry™ Control System

Most engines are equipped with an Oil Sentry™ oil monitor control system. When the oil level within the crankcase falls below the safe level, the engine stops automatically. Unless the oil level is brought up to the proper level the oil warning light will flicker for a few seconds when attempting to start, and the engine will not start. See Figure 8-2.

Bring Level Up To Point of Overflow

Proper

Oil Level

Low Oil

Level

Figure 8-2. Cutaway Showing Proper Oil Level.

Oil Sentry™ systems typically consist of the following components:

• An oil warning control unit (black box).

• An oil level float switch.

• An indicator light.

8.3

Section 8 Electrical System and Components

Troubleshooting Guide

Ignition and Oil Sentry™ Systems

Before testing, be certain all electrical leads are connected and crankcase oil is at the point of overflowing the filler neck.

Problem Test Conclusion

Engine Will

Not Start

1. Disconnect the cap from the spark plug and attach it to the terminal end of spark tester Kohler Part No. 25 455 01-S. Attach tester spring clip to a good ground, not to the spark plug. Turn ignition/key switch ‘‘on’’ and crank the engine while observing the firing tip of the tester.

2. On electric start engines, remove the starter cover panel. Locate the black/white kill lead coming from the ignition module inside the blower housing. Disconnect the bullet connector where the kill lead plugs into the harness. Repeat the spark test (step 1).

3. Trace the blue lead from the Oil Sentry control module. Disconnect the bullet connector where it joins the lead from the Oil

™

Sentry Repeat spark test again.

4. Connect a jumper lead from the blue lead terminal to a bare spot on the crankcase (ground). Turn the ignition switch ‘‘on’’, crank the engine, and observe the red LED indicator lamp.

a. If the indicator lamp was not flashing,

float switch (black with gray sleeve).

trace the black (manual start models) or black/white (electric start models) lead from the ignition switch. Separate the bullet connector where the switch lead joins the double red harness lead. Crank the engine, again observing the red LED indicator lamp.

™

1. If tester is firing, ignition system is good. Install a new spark plug and try to start engine. If it still will not start, check other possible causes (fuel, compression, etc.). If tester does not fire, go to step 2.

2. If spark is now present, check for a shorted lead in the kill circuit or a faulty switch (step 7). If there is still no spark, go to step 3.

3. If spark is now present, the control module or float switch is faulty. Test the control module (step 4) and the float switch (step 5). If there is still no spark, test the ignition module (step 6).

4. If the indicator lamp flashes during cranking, the control module is functioning, proceed to step 5. If the lamp was not flashing initially but did flash in step 4a, the control module is good, but the ignition switch is probably faulty. Test the float switch (step 5) and the ignition switch (step 7).

8.4

5. Set an ohmmeter to the Rx1 scale and zero the meter. Connect one ohmmeter lead to the Oil

™

Sentry sleeve) and touch the other lead to a bare spot on the crankcase (ground). Drain the oil from the crankcase and repeat the test.

a. If continuity was indicated with and

b. With the float switch removed, connect

float switch lead (black with gray

without oil above, check if the insulation has been scraped off the float switch lead.

one ohmmeter lead to the float switch lead terminal and connect the other lead to mounting bracket. Test resistance with the switch in the normal position and inverted.Repeat test 2 or 3 times in each direction.

5. With the oil at the proper level, no continuity should have been indicated. After the oil was drained, continuity should have been indicated. If test results are other than specified, remove the closure plate from the engine and remove the float switch for further testing (5a and 5b).

a. If the lead wire is bare, allowing it to short,

repair with electrical tape or replace float switch.

b. Switch continuity should be as indicated in

Figure 8-3. If not, replace it.

Electrical System and Components

Problem Test Conclusion

Section 8

Engine Will

Not Start

6. Set an ohmmeter to the Rx1K or Rx10K scale and zero. Connect one ohmmeter lead to the kill lead (black/white) terminal and connect the other lead into the spark plug cap.

a. Remove the cap from the spark plug lead

and test the resistance of the cap alone.

b. If resistances are other than specified,

remove the blower housing and remove the ignition module. With the kill lead and spark plug cap removed, test resistance from the small spade terminal to the core of the spark plug lead wire.

7. Set an ohmmeter to the Rx1 scale and zero the

meter. Test the ignition/key switch as follows.

a. On manual start engines, trace the two

black leads from the on/off switch and separate them from any connections. Connect the ohmmeter leads to the switch leads, and check for continuity in both switch positions.

b. On electric start engines, trace the four

leads (red, red/white, black, black/white) from the key switch and separate them from any connections. Connect the ohmmeter leads to the black and black/white leads and check for continuity in all three switch positions. Then connect the ohmmeter leads to the red and red/white leads and test again in all three switch positions.

6. Resistance of the ignition module should be

13.5-18.0 K ohms.

a. Resistance of the cap should be

4-6 K ohms.

b. Resistance should be 9.5-12.9 K ohms . If

resistance is not in this range, replace the module.

a. Continuity should be indicated when and

only when switch is in the ‘‘off’’ position. Replace switch for any other results.

b. Continuity should be indicated between the

black and black/white leads only when the key switch is in the off position. There should be continuity between the red and red/white leads only in the start position. Replace switch for any other results.

Continuity No Continuity

Figure 8-3.

8.5

Section 8 Electrical System and Components

Battery Charging Systems

General

CS engines may be equipped with a 7 amp, 10 amp, or 18 amp regulated battery charging system. Refer to the selection tables below and the appropriate wiring diagram, based upon the specific Model and Spec. No.

Wiring Diagram Selection Tables

The following selection tables and individual wiring diagrams (Figures 8-4 through 8-22) provide a reference for troubleshooting and servicing. Locate the appropriate diagram based on the Model and Spec. No. involved.

Model No. Spec. No. Figure No. Page No.

CS4T CS4T

CS4T CS4TR CS4TP

CS4T

CS4TG

CS4TR

Model No. Spec. No. Figure No.

CS6T

CS6TR

CS6TP

CS6TG

S6T

CS6TR

CS6ST

CS6TG CS6TG

CS6T CS6ST

CS6T

CS6TG CS6TG CS6TR

901501 901502 901503 901504 901505 901506 901511 901512

911501 911502 911503 911504 911505 911506 911507 911508 911509 911510 911511 911512 911513 911514 911515 911516 911517 911518 911519

8-4 8-5 8-5 8-5 8-5 8-6 8-5 8-5

8-4 8-5 8-5 8-5 8-5 8-5 8-6 8-5 8-7 8-5 8-5 8-6 8-7 8-4 8-4 8-7 8-5 8-4 8-4

8.8

8.9

8.8

Page No.

8.8

8.9

8.8

8.9

8.8

8.9

8.8

8.9

8.8

Model No. Spec. No. Figure No. Page No.

CS8.5T

CS8.5T CS8.5TP CS8.5TR CS8.5TR

CS8.5TG CS8.5TG

CS8.5ST CS8.5ST

CS8.5TG

Model No. Spec. No.

CS8.5T

CS8.5T CS8.5TP CS8.5TR CS8.5TR

CS8.5TG CS8.5TG

CS8.5ST

CS8.5T

CS8.5TG

CS8.5ST

CS8.5TG

CS8.5ST

CS8.5T

CS8.5T CS8.5TR

CS8.5T

921501 921502 921503 921504 921505 921506 921509 921507 921508 921510

951500 951501 951502 951503 951504 951505 951506 951507 951508 951509 951510 951511 951512 951513 951514 951515 951516 951517 951518

8-5 8-5 8-5 8-5 8-5 8-5 8-5 8-8 8-9 8-5

Figure No.

8-12 8-12 8-12 8-12 8-12 8-12 8-12 8-12 8-13 8-12 8-14 8-12 8-19 8-12 8-12 8-12 8-12 8-21 8-21

8.8

8.10

8.8

Page No.

8.12

8.13

8.12

8.15

8.12

8.16

8.6

Section 8

Electrical System and Components

Model No. Spec. No. Figure No.

CS10T

CS10T CS10TG CS10TP CS10TR CS10TR

CS10STG

CS10ST

CS10S

CS10ST

CS10TG

CS10 CS10T CS10T

CS10TG CS10TP CS10TR CS10TR

CS10STG

CS10ST

CS10S

CS10ST CS10TG CS10TG

CS10STG

CS10TG CS10TR

CS10T CS10STG CS10STG

CS10TG

CS10T

CS10TR

Model No. Spec. No.

CS12T

CS12T CS12TG CS12TG

CS12TP CS12TR

CS12TR CS12STG CS12STG

CS12ST

CS12S

CS12ST

CS12GT

931501 931502 931503 931504 931505 931506 931507 931508 931509 931510 931511 931512 931601 931602 931603 931604 931605 931606 931607 931608 931609 931610 931611 931612 931614 931615 931616 931617 931618 931619 931620 931621 931622

941501 941502 941503 941511 941504 941505 941506 941507 941512 941508 941509 941510 941513

8-5 8-5 8-5 8-5 8-5 8-5 8-8 8-8 8-8 8-9 8-5 8-5 8-5 8-5 8-5 8-5 8-5

8-5 8-16 8-16 8-16 8-17

8-6

8-6 8-18

8-6 8-22

8-5 8-18 8-18

8-5 8-19 8-19

Figure No.

8-5 8-5 8-5 8-5 8-5 8-5 8-5 8-8 8-8 8-8 8-8 8-9 8-5

Page No.

8.8

8.10

8.8

8.14

8.9

8.15

8.9

8.17

8.8

8.15

8.8

8.15

Page No.

8.8

8.10

8.8

Model No. Spec. No.

CS12STG CS12STG CS12STG CS12STG CS12STG

CS12T CS12S

Model No. Spec. No.

CS12T CS12T

CS12TG

CS12TP CS12TR CS12TR

CS12STG

CS12ST

CS12S

CS12ST

CS12TG

CS12STG

CS12TG CS12STG CS12STG CS12STG CS12STG CS12STG

CS12T

Hydro 12.75

CS12S

CS12STG

CS12TG CS12STG

CS12TR

CS12T

CS12ST CS12STR CS12STG

CS12ST CS12STG CS12STG

CS12T

CS12ST

CS12T CS12TR CS12ST

CS12TG

941515 941516 941517 941518 941519 941520 941521

941601 941602 941603 941604 941605 941606 941607 941608 941609 941610 941611 941612 941613 941615 941616 941617 941618 941619 941620

941621 941622 941623 941624 941625 941626 941627 941628 941629 941630 941631 941632 941633 941634 941635 941636 941637 941638

Figure No.

8-10 8-10 8-11 8-15 8-10

8-5 8-5

Figure No.

8-5 8-5 8-5 8-5 8-5

8-5 8-16 8-16 8-16 8-17

8-5 8-16

8-5 8-18 8-18 8-18 8-16 8-18

8-6

8-6 8-18

8-5 8-18

8-5

8-5 8-16 8-16 8-18 8-16 8-18 8-16

8-5 8-20 8-19 8-19 8-16

8-5

Page No.

8.11

8.13

8.11

8.8

Page No.

8.8

8.14

8.8

8.14

8.8

8.15

8.14

8.15

8.9

8.15

8.8

8.15

8.8

8.14

8.15

8.14

8.15

8.14

8.8

8.16

8.15

8.14

8.8

8.7

Section 8 Electrical System and Components

Ignition Module

Spark Plug

Stop Switch

Wire Lead B

Electronic Ignition System, Recoil Start.

Figure 8-4.

Ground

Wiring Color Codes

B L R Y

Gy B/W R/W W/L

G/R G/Y

L/W

L/R

G/B

Oil Sentry™ Gauge Lead

Black

Blue

Red

Yellow

White

Brown

Green

Gray

Black w/White Stripe

Red w/White Stripe

White w/Blue Stripe

Green w/Red Stripe

Green w/Yellow Stripe

Blue w/White Stripe

Blue w/Red Stripe

Green w/Black Stripe

Black w/Gray Shielding

Ignition Module

Spark Plug

Wire Lead

Electronic Ignition System, with Oil Sentry™ System. Recoil Start.

Figure 8-5.

Stop Switch

Ground

Oil Warning

Ground

BW BW

Oil Sentry™ Light

R or BR

Unit

Oil Sentry™ Gauge

Ground

8.8

Oil Warning Unit

Section 8

Electrical System and Components

Ground

Oil Sentry™ Gauge

Ground

Electronic Ignition System, 7 Amp Unregulated Charging System, with Oil Sentry™ System. Recoil Start.

Figure 8-6.

Oil Warning Unit

Ground

Wire Lead

Oil Sentry™ Gauge

Ground

R or BR

Oil Sentry™ Light

Ignition Module

Spark Plug

Ground

R or BR

Stator

Oil Sentry™ Light

Spark Plug

R or BR

Ground

Ignition Module

Engine Ground

R or BR

Stop Switch

RWRBBW

Wire Lead

Ground

Starter Solenoid

Stator

Ground

Wire Color

Off

Start

Main Switch

Fuse (15 A)

Battery

RRW

Electronic Ignition System, 7 Amp Charging System, with RectifierRegulator, and Oil Sentry™ System. Electric Start (Inertia Drive St arter).

Figure 8-7.

Rectifier-Regulator

Ground

Starter Motor

8.9

Section 8 Electrical System and Components

Oil Warning Unit

Ground

Wire Lead

Oil Sentry™ Gauge

Ground

Oil Sentry™ Light

Ignition Module

Spark Plug

Ground

Engine

Ground

Stator

Main Switch

BW B

BBW

RWR

Ground

Starter Solenoid

Wire Color

Off

W R

Start

Fuse (15 A)

Battery

Electronic Ignition System, 10 Amp Charging System, with RectifierRegulator, and Oil Sentry™ System. Electric Start (Inertia Drive St arter).

Figure 8-8.

Oil Warning Unit

Ground

Wire Lead

Oil Sentry™ Gauge

Ground

Oil Sentry™

Light

Ignition Module

Spark Plug

Stator

Ground

Rectifier-Regulator

Ground

Main Switch

Wire Color

Off

Engine

Ground

WWWL R

Start

Fuse (20 A)

Battery

BBW

BR RW

RBR

Charge Lamp

Starter Motor

Ground

Starter Solenoid

Electronic Ignition System, 18 Amp Charging System, with RectifierRegulator, and Oil Sentry™ System. Electric Start (Inertia Drive St arter).

Figure 8-9.

8.10

Rectifier-Regulator

Charge Lamp

Ground

Starter Motor

Ground

Wire Lead

Oil Sentry™ Gauge

Oil Warning Unit

Ground

Spark Plug

Oil Sentry™ Light

Ignition Module

Ground

Electrical System and Components

YR YR

Rectifier

Fuse

Section 8

Main Switch

BW B R RWWire Color Off On

Start

RRW

Starter Solenoid

Ground

Electronic Ignition System, 0.4 or 2 Amp Charging System, Rectified Only . Oil Sentry™ System. Electric Start (Inertia Drive St arter).

Figure 8-10.

Oil Warning Unit

GroundGround

Ground

Wire Lead

Oil Sentry™ Gauge

Ground

Spark Plug

Ground

Oil Sentry™ Light

Ignition Module

Electronic Ignition System, 1.6 Amp Charging System, Rectified Only . Oil Sentry™ System. Electric Start (Inertia Drive St arter).

Figure 8-11.

Battery

Starter Motor

Ground

Off On

Start

Rectifier

Fuse

Battery

Ground

Main Switch

BRRWWire Color

Starter Motor

RRW

Ground

Starter Solenoid

8.11

Section 8 Electrical System and Components

Oil Warning Unit

Ground

Oil Sentry™ Gauge

Ground

Electronic Ignition System Oil Sentry™ System, with Indicator Light (Some Models), Recoil Start.

Figure 8-12.

Oil Warning Unit

Stator

Ground

Wire Lead

Oil Sentry™ Gauge

Ground

Oil Sentry™ Light

Ignition Module

Spark Plug

Electronic Ignition System, 3 Amp Charging System, Rectified Only . Oil Sentry™ System. Electric Start (Solenoid Shift St arter).

Not on All Models

Oil Sentry™ Light

Spark Plug

Engine Ground

Ground

Ignition Module

GG R

Rectifier

Stop Switch

Stator

Ground

Main Switch

BW Off On

Start

BW R RW

Ground

Fuse (10 A)

Battery

Engine Ground

Ground

BRRWWire Color

Starting Motor

Ground

Figure 8-13.

8.12

Ground

Oil Sentry™ Gauge

Oil Warning Unit

Ground

Oil Sentry™ Gauge

Ignition Module

Spark Plug

Ground

Electrical System and Components

Stop

Stator

Switch

Engine Ground

Ground

WW RR

BR R

Section 8

Electronic Ignition System 18 Amp Charging System, Rectified Only . Oil Sentry™ System. Recoil Start.

Figure 8-14.

RectifierAssembly

Rectifier-Regulator

GR GB

BLW

Carb. Heater

(-)Y(+)B(-)

(-)

LW GR Y GB

Fuel Shut-Off Solenoid

LW GB

Electronic Ignition System, 10 Amp Charging System, with Rectifier-Regulator, and Oil Sentry™ System. Electric Start (Inertia Drive Starter)

Rectifier-Regulator

Special Generator Application Options.

W BR R

Oil Sentry™ Light

YBW

YBWYL

Oil Warning Unit

GB GR BW

Stator

Ground

BWGRGB

Ignition Module

Ground

Spark Plug

Ground

Oil Sentry™ Gauge

Starter Solenoid

Rectifier

Ground

RW R

Ground

B R RW Y LR

Starter Motor

BW B

R RW

Battery

Off On

Start

Ground

Main Switch

Fuse (15 amp)

RRBYLR

Figure 8-15.

8.13

Section 8 Electrical System and Components

10 Amp Charging System with Rectifier-Regulator and Oil Sentry™ System. Solenoid Shift Electric St arter .

Figure 8-16.

18 Amp Charging System with Rectifier-Regulator and Oil Sentry™ System. Solenoid Shift Electric Starter and Provisions for Charge Lamp.

Figure 8-17.

8.14

Section 8

Electrical System and Components

0.4 or 2 Amp Charging System-Rectified Only and Oil Sentry™ System. Solenoid Shift Electric Starter . Optional Solenoid Valve (Some Models).

Figure 8-18.

18 Amp Charging System with Rectifier-Regulator and Oil Sentry™ System. Solenoid Shift Electric St arter and Provisions for Charge Lamp. Spec. Specific Ignition Switch and Wiring Harness Connectors.

Figure 8-19.

8.15

Section 8 Electrical System and Components

No Charging System, Operational Off Battery . Oil Sentry™ System. Solenoid Shift Electric St arter .

Figure 8-20.

Spark Plug

Ground

Ignition Module

Ground

Wire Lead

Stop Switch

Recoil Start No Oil Sentry™ System. Stop Switch Only.

Figure 8-21.

8.16

Ground

Oil Sentry™ Gauge

Oil Warning Unit

Ground

Oil Sentry™ LIght

Ignition Module

Spark Plug

Ground

Section 8

Electrical System and Components

Stop Switch

Stator

Ground

BR R

RRB

10 Amp Charging System Recoil Start Only Oil Sentry™ System.

Figure 8-22.

RectifierRegulator

8.17

Section 8 Electrical System and Components

NOTE: Observe the following guidelines to avoid

damage to the electrical system and components.

• Make sure the battery polarity is correct. A negative (-) ground system is used.

• Make sure all ground connections are secure and in good condition.

• Disconnect both battery cables before doing electrical welding on the equipment powered by the engine. Also, disconnect other electrical accessories in common ground with the engine.

• Prevent the stator (AC) leads from touching or shorting while the engine is running. This can damage the stator.

Stator

The stator is mounted on the crankcase behind the flywheel. Should the stator have to be replaced, follow the procedures in Section 9 Disassembly.

18 Amp Rectifier-Regulator

The 18 amp rectifier-regulators contain a 6-terminal plug-in configuration, illustrated in Figure 8-23. The upper center terminal is the control or monitor terminal, through which the regulator monitors battery voltage. This terminal is connected internally to SCRs, which are turned on and off as required, controlling the battery voltage between 14 and 15 volts. The connection between the B+ (charge) lead and the monitor terminal lead is made within the wiring harness. The lower center terminal serves as a connection for a pilot lamp circuit, to indicate when the charging system is functioning.

Monitor T erminal (Red)

B+ Charge (Red)

–

Ground (Black)

Rectifier-Regulator

The rectifier-regulator is connected to the engine with a matching wiring harness containing a plug-in connector. Grounded through the wiring harness, the rectifier-regulator is secured to the equipment in a suitable location with two mounting screws. To replace it, disconnect the plug, and remove the two mounting screws.

NOTE: When installing the rectifier-regulator, push

the wiring harness plug into the regulator receptacle until it locks into place.

The rectifier-regulator converts the AC voltage coming from the stator to DC voltage, while also monitoring and controlling the battery voltage. There are two different rectifier-regulators which are used; an 18 amp and a 7/10 amp assembly. Although externally similar, the internal circuits differ and the two should not be interchanged.

Stator AC Leads (White)

Figure 8-23. 18 Amp Rectifier-Regulator .

7/10 Amp Rectifier-Regulator

The 7/10 amp rectifier-regulators contain a 5-terminal plug-in configuration (See Figure 8-24), with two differences from the 6-terminal/18 amp system. Battery voltage is monitored by the internal circuitry of the rectifier-regulator instead of through the lead connection at the upper center location. The terminal in the upper center location serves no function. No lower center (pilot lamp) terminal exists on the 7/10 amp rectifier-regulator.

B+ Charge (Red)

Pilot Lamp Terminal

Ground (Black)

–

8.18

Stator AC Leads (White)

Figure 8-24. 7/10 Amp Rectifier-Regulator .

Floating/Isolated Terminal

Rectified Only (Non-Regulated) Systems

Some engines are equipped with a rectified only, non-regulated charging system, with output ranging from 0.2 amp to 18 amps. The rectifier is normally connected to the engine with a matching wiring harness and secured to the equipment with a single mounting screw. Grounding is achieved through the wiring harness. In certain other applications the rectifier may be integrated within the basic engine wiring harness. The rectifier converts AC voltage coming from the stator to DC voltage only. The 3 amp rectifier is shown in Figure 8-25.

DC V oltmeter

Section 8

Electrical System and Components

Figure 8-25. 3 Amp Rectifier .

Rectifier-Regulator

(+)

(–)

Battery

Figure 8-26. Connections for T esting Charging Systems.

Ammeter

Plug in Connector

Connect T ester Leads to Female Bullet Connector (Red Wire)

Ground Lead (Black)

Stator AC Leads (White)

8.19

Section 8 Electrical System and Components

Troubleshooting Guide

Battery Charging System

NOTE: Zero ohmmeters on each scale to ensure accurate readings. Voltage tests should be made with engine

running at 3600 RPM - no load. Battery must be fully charged. Check the specific gravity of battery. If low, recharge or replace battery as necessary.

Problem Test Conclusion

Charge

Battery

1. Refer to Figure 8-26. Separate the bullet connector in the red lead from the rectifierregulator. Connect an ammeter from the female terminal to the positive (+) terminal of the battery. Connect a DC voltmeter from the female terminal to the negative (-) terminal of the battery. Leave the other rectifier-regulator leads connected in the normal manner. Run the engine at 3600 RPM and read the voltage on the voltmeter.

If voltage is 14.0 volts or more, place a minimum load of 5 amps* on battery to reduce voltage. Observe ammeter.

*NOTE: Turn on lights (if 60 watts or more)

or place a 2.5 ohm, 100 watt resistor across battery terminals.

2. Separate the bullet connectors in the AC (white) leads. Connect an AC voltmeter across the stator leads (female terminals). With engine running at 3600 RPM, measure the AC output from the stator.

3a. With engine stopped, measure the resistance

across stator/charging leads using an ohmmeter. Compare the meter reading obtained against the specified range, based on the charging system involved.

1. If voltage is 14.0-15.0 volts and charge rate

increases when load is applied, the charging system is OK and the battery was fully charged.

If voltage is less than 14.0 volts or charge rate does not increase when load is applied, test stator (Tests 2 and 3).

2. If voltage is 20.0 volts or more, stator is OK.

Rectifier-regulator is faulty. Replace the rectifier-regulator.

If voltage is less than 20.0 volts, stator is probably faulty and should be replaced. Test stator further using an ohmmeter (Test 3).

3a. If resistance value obtained is within the range

specified the stator is OK.

metsySgnigrahC)smho(ecnatsiseRlamroN

pma6.1dna2.1smho6.1-09.0

pma0.3dna58.0smho05.0-82.0

pma81dna,01,7smho03.0-01.0

Battery

Continuously

Charges at

High Rate

8.20

3b. With the engine stopped, measure the

resistance from each stator lead to ground using an ohmmeter.

1. Perform same test as step 1 above.

3b. If the resistance is infinity ohms (no

continuity), the stator is OK (not shorted to ground).

If resistance (or continuity) is measured, the stator leads are shorted to ground. Replace stator.

1. If the voltage is 15.0 volts or less the charging

system is OK. The battery is unable to hold a charge. Service or replace battery as necessary.

If voltage is more than 15.0 volts, the rectifier-regulator is faulty. Replace the rectifier-regulator.

Section 8

Electrical System and Components

Battery

General

A 12 volt battery (not furnished) with a minimum current rating of 160 (CS4, CS6) or 200 (CS8.5-12) cold cranking amps should be sufficient for cranking most electric start engine models. The actual cold cranking requirement depends on engine size, application and starting temperatures. Cranking requirements increase as temperatures decrease and battery capacity shrinks. Refer to the operating instructions of the equipment this engine powers for specific battery requirements.

If the battery charge is not sufficient to turn over the engine, recharge the battery.

Battery Maintenance

Regular maintenance is necessary to prolong battery life.

WARNING: Explosive Gas!

2. Keep the cables, terminals, and external surfaces of the battery clean. A build-up of corrosive acid or grime on the external surfaces can cause the battery to self-discharge. Self-discharge occurs rapidly when moisture is present.

3. Wash the cables, terminals, and external surfaces with a mild baking soda and water solution. Rinse thoroughly with clear water.

NOTE: Do not allow the baking soda solution to

enter the cells as this will destroy the electrolyte.

Battery T est

To test the battery, you will need a DC voltmeter. Perform the following steps (See Figure 8-27).

1. Connect the voltmeter across the battery terminals.

2. Crank the engine. If the battery drops below 9 volts while cranking, the battery is discharged or faulty.

DC V oltmeter

1. Regularly check the level of electrolyte. Add distilled water as necessary to maintain the recommended level.

NOTE: Do not overfill the battery. Poor

performance or early failure due to loss of electrolyte will result.

Battery

Figure 8-27. Battery V oltage Test.

8.21

Section 8 Electrical System and Components

Electric Starting Motors

Electric start engines in this series will use either an inertia drive, or a solenoid shift starter. Each style has its own respective starter solenoid incorporated into the mounting configuration. The inertia drive starters are covered first, beginning on page 8.25, and the solenoid shift style covered starting on page 8.31.

Starting Motor Precautions

NOTE: Do not crank the engine continuously for

more than 10 seconds at a time. If the engine does not start, allow a 60 second cool-down period between starting attempts. Release the switch as soon as the engine starts. Failure to follow these guidelines can burn out the starter motor.

NOTE: If the engine develops sufficient speed to

disengage the starter but does not keep running (a false start), the engine rotation must be allowed to come to a complete stop before attempting to restart the engine. If the starter is engages while the flywheel is rotating, the starter pinion and flywheel ring gear may clash, resulting in damage of the starter.

NOTE: If the starter does not crank the engine, shut

off the starter immediately. Check the condition of the inline fuse and do not make further attempts to start the engine until the condition is corrected.

NOTE: Do not drop the starter or strike the starter

housing. Doing so can damage the starter.

Starter Removal and Inst allation

Refer to the Disassembly and Reassembly sections for starter removal and installation procedures.

Troubleshooting Guide – S tarting Difficulties

Problem Possible Fault Correction

1. Check the specific gravity of battery. If low, recharge or replace battery as necessary.

1. Check fuse condition.

2. Clean corroded connections and tighten loose connections.

3. Replace wires in poor condition and with frayed or broken

insulation.

1. Check the switch or solenoid operation. If starter cranks normally, replace the faulty components.

1. Check the specific gravity of battery. If low, recharge or replace battery as necessary.

1. Check for corroded connections, poor ground connection.

1. Check for excessively dirty or worn brushes and commutator. Clean using a coarse cloth (not emery cloth).

2. Replace brushes if excessively or unevenly worn.

1. Make sure the clutch or transmission is disengaged or placed in neutral. This is especially important on equipment with hydrostatic drive. The transmission must be exactly in neutral to prevent resistance which could keep the engine from starting.

2. Check for seized engine components such as the bearings, connecting rod, and piston.

Starter

Does Not

Energize

Starter

Energizes

But Turns

Slowly

Battery

Wiring

Starter Switch

or Solenoid

Battery

Wiring

Brushes

Transmission

Engine

8.22

Electrical System and Components

Troubleshooting Guide – Electric S t arting System

Problem Test Conclusion

Starter

Motor Does

Not Operate

With Key

Switch

1. Test battery on unit.

a. Connect a DC voltmeter across the battery

terminals and read battery voltage (key switch off).

b. Turn key switch to start position and

read battery voltage again. Turn switch off.

2. Remove the electric starter cover panel and check the fuse inside the plastic holder. The fuse outside the holder is a spare.

3. Disconnect the red/white solenoid lead from red/ white switch lead at the bullet connection. Be sure transmission is in neutral and PTO is off. Connect one end of a jumper lead to the positive terminal of the battery. Connect the other end to the terminal of the red/white solenoid lead.

4. Use a known, good, fully-charged battery and jumper cables to test starter motor. Be sure the transmission is in neutral and PTO is off. Inertia Drive Starters: Remove the heavy lead from the post terminal on the starter. Connect one end of the positive jumper cable to the post terminal and connect the other end to the positive terminal of the battery. Solenoid Shift Starters: Connect one end of the positive jumper cable to the positive brush lead attached to the lower stud terminal of solenoid. Connect the other end to the positive terminal of the battery. Connect one end of the negative jumper cable to the negative terminal of the battery. Touch the other end of the negative jumper cable to a bare surface on the crankcase or to the starter housing.

1. a. Battery voltage should be at least 12 volts

If low charge battery.

b. Battery voltage should not fall below 9 volts

during cranking. If it does, battery may be faulty or there may be a short in the starting circuit. Have battery load tested. If battery passes load test, check circuitry.

2. If fuse is blown, check for a wiring problem (bare wire, short circuit). Correct problem and replace fuse. Try to start engine. If it still won’t start, go to step 3.

3. If solenoid engages and starter begins to crank, the key switch is faulty, or there is a wiring problem to/from the key switch. Check wiring and test key switch circuits with an ohmmeter.

4. When negative jumper cable is touched to crankcase or starter housing, starter motor should operate. If it does, continue with step 5. If starter does not operate, refer to the servicing procedures for the starter motor and check out the brushes and armature. Repair or replace as required.

Section 8

5. Inertia Drive Starters: Disconnect the leads from

the starter solenoid and remove it from the starter for testing. See Figure 8-33 on page 8.25.

a. Set an ohmmeter on the Rx1 scale and zero

the meter. Connect one ohmmeter lead to the terminal of the red/white lead from the solenoid. Connect the other ohmmeter lead to the solenoid mounting bracket.

b. With the ohmmeter still on the Rx1 scale,

connect the leads to the two large post terminals.

c. Leave the ohmmeter leads connected to the

large terminals. Connect a jumper lead from the positive terminal of the battery to the terminal of the red/white solenoid lead. Connect another jumper lead from the negative terminal of the battery to the solenoid mounting bracket.

Solenoid Shift Starters: Perform the solenoid tests on page 8.24.

5. a. The resistance of the energizing coil should

be at least 3.4 ohms. If the meter reading is less than 3.4 ohms, or an open circuit is indicated (infinity ohms), the solenoid is faulty and must be replaced.

b. The meter should indicate an open circuit

(infinity ohms, no continuity).

c. When the circuit is completed, applying 12

volts to the energizing coil, an audible click should be heard as the solenoid engages, and the ohmmeter should then indicate continuity between the large terminals. If the results are other than indicated, replace the solenoid.

8.23

Section 8 Electrical System and Components

Solenoid Test Procedure

Solenoid Shift Style St arters

Disconnect all leads from the solenoid including the positive brush lead attached to the lower stud terminal. Remove the mounting hardware and separate the solenoid from the starter for testing.

T est 1. Solenoid Pull-In Coil/Plunger Actuation Test.

Use a 12 volt power supply and two test leads. Connect one lead to the flat spade “S/start” terminal on the solenoid. Momentarily* connect the other lead to the lower large post terminal. See Figure 8-28. When the connection is made the solenoid should energize (audible click), and the plunger retract. Repeat the test several times. If the solenoid fails to activate, it should be replaced.

*NOTE: DO NOT leave the 12 volt test leads

connected to the solenoid for any time over what is necessary for performing each of the individual tests. Internal damage to the solenoid may otherwise occur.

12 volt T est Leads Momentary Connection Only

VOM Leads

Figure 8-29. T esting Pull-In Coil/Solenoid Contact Continuity.

Test 3. Solenoid Hold-In Coil Function Test.

Connect one 12 volt test lead to the flat spade “S/ start” terminal on the solenoid, and the other lead to the body or mounting surface of the solenoid. Then, manually push the plunger “In” and check if the “Hold-In” coil holds the plunger retracted. See Figure 8-30. Do not allow the test leads to remain connected to the solenoid for a prolonged period of time. If the plunger fails to stay retracted, the solenoid should be replaced.

12 volt Test Leads Momentary Connection Only

Figure 8-28. T esting Pull-In Coil/Plunger Actuation.

T est 2. Solenoid Pull-In Coil/Cont act Continuity Test.

Use an ohmmeter set to the audible or Rx2K scale, and connect the two ohmmeter leads to the two large post terminals. Perform the preceding test (1) and check for continuity. See Figure 8-29. The ohmmeter should indicate continuity, if no continuity is indicated the solenoid should be replaced. Repeat test several times to confirm condition.

Manually Push Plunger “In”

12 volt T est Leads Connect Only Long Enough to T est

Figure 8-30. T esting Hold-In Coil/Function T est.

T est 4. Solenoid Hold-In Coil/Contact Continuity Test.

Use an ohmmeter set to the audible or Rx2K scale, and connect the two ohmmeter leads to the two large post terminals. Perform the preceding test (3) and check for continuity. See Figure 8-31. The meter should indicate continuity, if no continuity is indicated the solenoid should be replaced. Repeat test several times to confirm condition.

8.24

VOM Meter

Plunger Pushed “In”

12 volt Test Leads

Figure 8-31. T esting Hold-In Coil/Solenoid Cont act Continuity.

Leads

Inertia Drive Electric Starters

This subsection covers the operation, troubleshooting, and repair of the inertia drive, permanent magnet electric starter.

Section 8

Electrical System and Components

Operation

When power is applied to the starter, the armature rotates. As the armature rotates, the drive pinion moves out on the splined drive shaft and into mesh with the flywheel ring gear. When the pinion reaches the end of the drive shaft, it rotates the flywheel and cranks the engine.

When the engine starts, the flywheel rotates faster than the starter armature and drive pinion. This moves the drive pinion out of mesh with the ring gear and into the retracted position. When power is removed from the starter, the armature stops rotating and the drive pinion is held in the retracted position by the anti-drift spring.

Starter Drive Service

Every 300 hours of operation (or annually, whichever occurs first), clean and lubricate the splines on the starter drive shaft. If the drive pinion is worn, or has chipped or broken teeth, it must be replaced.

Figure 8-32. Inertia Drive Starter.

Post T erminals

Red/White Lead

It is not necessary to completely disassemble the starter to service the drive components. Service the drive as follows:

Retaining

Ring

Drive Pinion

Spring

Spring Holder (Collar)

Figure 8-34. Drive Components.

1. Remove the starter from the engine.

2. Push back the spring holder (collar) to expose the retaining ring on the armature shaft, which secures the drive components. Remove the retaining ring using either of the Kohler retaining ring removal tools.

Figure 8-33. Solenoid Details.

8.25

Section 8 Electrical System and Components

Figure 8-35. Removing Retaining Ring.

3. Remove the spring holder (collar), spring and drive pinion assembly from the armature shaft.

Figure 8-36. Disassembled Drive Components.

4. Use a solvent to thoroughly clean any dirt or old lubricant from the splines.

5. Inspect the splines and drive components for wear or damage. If the splines are damaged, it will be necessary to replace the starter. The drive components are available as individual service parts if any of them are worn or damaged.

6. Apply a small amount of molybdenum disulfide lubricant to the splines.

7. Install the drive pinion, spring, and spring holder (collar) onto the armature shaft.

Figure 8-37. Installing Drive Components.

8. Install a new retaining ring into the groove of the armature shaft. Squeeze it with a pliers to compress it into the groove. It must fit into the recess in the end of the spring holder.

Figure 8-38. Installing Retaining Ring.

Starter Disassembly

1. Remove the retaining ring, spring holder (collar), spring, and drive pinion assembly from the armature shaft. Refer to Starter Drive Service.

2. Disconnect the solenoid lead from the starter terminal. Hold the lower jam nut from turning with a wrench while loosening the top nut, to prevent damaging internal components. See Figure 8-39. The solenoid may be removed or left in place.

8.26

Section 8

Electrical System and Components

Figure 8-39. Removing Solenoid Lead.

3. Scribe or mark a small line from the starter frame to each end cap to serve as match marks for reassembly later. See Figure 8-40.

Figure 8-40. Match Marks for Reassembly .

4. Remove the two thru bolts, with sealing O-Rings, from the starter. See Figure 8-41.

Figure 8-42. Removing End Cap with Brush Plate.

6. Pull the armature out of the starter frame.

Brush Inspection/Replacement

1. Remove the lower jam nut, metal washer, insulating washer, and O-Ring from the positive (+) stud. Carefully push the stud inward to separate the brush plate assembly from the end cap. See Figure 8-43.

Figure 8-41. Removing Starter Thru Bolt.

5. Remove the commutator end cap and brush plate assembly. See Figure 8-42.

Figure 8-43. Removing Brush Plate.

8.27

Section 8 Electrical System and Components

2. Inspect both the springs and brushes for wear, fatigue, or damage. Measure the length of each brush. The minimum length for each brush must be 9 mm (0.350 in.). See Figure 8-44. Replace the brush plate assembly if the condition of parts is out of specification or questionable.

Brushes

Wear limit length: 9 mm (0.35 in.)

Figure 8-44. Brush Checking.

Depth: 2 mm (0.079 in.)

Figure 8-46. Commutator Mica Depth.

Armature Coil

1. Use an ohmmeter set to the Rx1 scale. Touch the probes between two different segments of the commutator, and check for continuity. See Figure 8-47. Test all the segments. Continuity must exist between all or the armature is defective.

Spring

Figure 8-45. Brush Plate Details.

Armature Commutator

1. Clean and inspect commutator (outer surface). Use 600 grit sandpaper to clean if necessary.

2. Measure the mica (insulation depth between the commutator segments). The depth should be 2 mm (0.079 in.). If less, cut/scrape the mica to the proper measurement using a hacksaw blade or similar tool ground to fit between the segments. See Figure 8-46.

2. Check for continuity between the armature coil segments and the commutator segments. See Figure 8-47. There should be no continuity. If continuity exists between any two, the armature is defective.

3. Check armature windings/insulation for shorting. See Figure 8-47.

Insulation Check

Armature Coil

Figure 8-47. Armature Checking.

Continuity Check

–x1k

NOTE: The mica insulation of the commutator

must be undercut to ensure proper operation of the commutator.

8.28

Starter Reassembly

1. Position the thrust washer in the recess inside the drive end cap. Install cover gasket on housing flange if removed previously.

Figure 8-48. Installing Thrust Washer and Gasket.

2. Carefully apply one or two drops of oil to the bronze bushing in the drive end cap and wipe away any excess. Insert the armature shaft through the end cap.

Section 8

Electrical System and Components

Figure 8-50. Installing Frame.

4. With the brushes and brush springs in place on brush plate, align the tabs and install the brush plate in commutator end cap. Insert the positive brush stud, with plastic support, through hole in the end cap from the inside out. Install the O-Ring, fiber washer, metal washer, and inner hex jam nut. Tighten nut to secure but do not overtighten, or damage to the inside plastic support can occur.

Figure 8-49. Installing Armature.

3. Install the starter frame (magnet end first) over the armature, aligning the scribed marks made earlier. See Figure 8-50.

Figure 8-51. Assembled Brush Plate.

Figure 8-52. Brush Plate and T erminal Component s.

8.29

Section 8 Electrical System and Components

5. Assemble the end cap assembly to the starter, inserting the commutator below the brushes and gently guiding the end of the armature shaft into the bushing within the end cap, against the brush spring tension. See Figure 8-53.

Figure 8-53. Installing End Cap Assembly.

Figure 8-55. Assembling Starter Lead.

6. Align all scribe marks and install the thru bolts

with O-Rings. Torque the bolts to 5.3 N·m (48 in. lb.). See Figure 8-54.

Figure 8-54. T orquing Thru Bolts.

7. Attach the starter lead from the solenoid to the stud and add the lock washer and outer hex jam nut to secure. Hold the lower jam nut from turning with a wrench while tightening the top nut, to prevent damaging the internal components. See Figure 8-55.

Figure 8-56. Installing Solenoid Connections.

8. Apply a light film of molybdenum disulfide to the splines of armature shaft and install the drive pinion, spring, and spring holder.

9. Push the spring holder down and install a new retaining ring into the groove of the armature shaft. Squeeze it with a pliers to compress it into the groove. It must fit into the recess in the end of the spring holder.

10. Install the starter back onto the engine. Refer to Section 11 Reassembly.

Reinstall the protective boot over the connection. If the solenoid was removed from the starter, reinstall it at this time, and connect the starter lead to the lower large terminal. See Figure 8-56.

8.30

Section 8

Electrical System and Components

Solenoid Shift Electric Starter

The following subsection covers the solenoid shift electric starter. Much of the information in the proceeding subsection relates to this type starter also, so it is not repeated here. A Nippendenso solenoid shift starter is used.

Operation (Solenoid Shift St arter)

When power is applied to the starter, the electric solenoid moves the drive pinion out onto the drive shaft and into mesh with the flywheel ring gear. When the pinion reaches the end of the drive shaft, it rotates the flywheel and cranks the engine.

When the engine starts and the start switch is released the starter solenoid is deactivated, the drive lever moves back, and the pinion moves out of mesh with the ring gear into the retracted position.

Drive End Cap

Nut

Drive Lever

Dust Cover

Thrust Washer

Frame

Wire

Starter Assembly

Figure 8-57. Nippendenso Solenoid Shift Starter.

Solenoid

Nut

Armature

Retainer

Stop Collar

Drive Pinion

Bush Spring

Brushes

Brush Holder

Insulator

Commutator End Cap

Thru Bolt

8.31

Section 8 Electrical System and Components

Starter Disassembly

1. Remove flange nut and disconnect the braided wire from lower main solenoid terminal.

2. Remove the two hex flange nuts securing the solenoid, and carefully separate the solenoid from the starter assembly (the front end of solenoid must be lifted slightly to permit disengagement from drive lever in starter). See Figure 8-58.

Figure 8-58. Starter with Solenoid Removed.

3. Remove the two thru bolts.

4. Remove the commutator end cap from the starter frame and the rubber insulating grommet.

8. Pull outward on the pivot portion of the drive lever, and remove the drive lever and armature from the drive end cap. See Figure 8-60.

NOTE: When removing the lever and armature,

be careful not to lose the thrust washer.

Figure 8-60. Removing Drive Lever and Armature.

9. The stop collar is held in place by being snapped over the retainer from the bottom-up. The retainer is positioned in a groove in the armature shaft. To access the retainer, the stop collar must be pushed back or down towards the drive pinion. See Figure 8-61.

5. Carefully remove the insulator and brush springs from the brush holder.

6. Lift the four brushes out of their corresponding slots and remove the brush holder.

7. Remove the frame from around the armature and drive end cap. See Figure 8-59.

Figure 8-59. Disassembled Starter .

Figure 8-61. Starter Drive and Stop Components.

10. With the stop collar dislodged, the retainer can be removed from the armature shaft. Do not reuse the retainer.

11. Remove the drive pinion assembly from the armature for servicing/replacement.

12. Clean all parts and the splines on the armature as necessary.

8.32

Brush Replacement

The brushes in the starter are part of the starter frame. The brush kit, Kohler Part No. 52 221 01-S, contains four replacement brushes and springs. If replacement is necessary, all four brushes should be replaced.

1. Remove brushes from brush holder, and remove brush holder from frame.

2. Cut the brush lead wire at the edge of the post with a pair of nippers.

3. File off burrs on the post.

Section 8

Electrical System and Components

4. The replacement brushes have a solid portion on them which should be crimped on the post.

5. Solder the crimped portion to the post.

6. Replace the brush holder in the frame and place the brushes in the brush holder. Reinstall the springs.

Starter Service

Clean drive lever and armature shaft. Apply Kohler electric starter drive lubricant (See Section 2) to lever and shaft.

Starter Reassembly

1. Install the drive pinion onto the armature shaft.

2. Slide the stop collar onto the armature shaft below the retaining ring groove. Make sure the recessed side of the stop collar is up.

3. Position a new retainer in the groove of armature shaft, and carefully tighten with a pliers to secure.

Figure 8-62. Lock Collar around Retaining Ring.

5. Install the thrust washer onto the armature shaft and lightly lubricate the end of the shaft with drive lubricant.

6. Position the lubricated drive lever around the drive pinion assembly and insert the assembly into the drive end cap. Seat the pivot section of drive lever into the corresponding section within the housing. See Figure 8-63.

NOTE: Always use a new retainer. Do not nick

or damage armature shaft.

4. Use an open end wrench and slide the stop collar up until the recessed section encases the retaining ring and locks the collar into position. See Figure 8-62.

Figure 8-63. Installing Armature.

8.33

Section 8 Electrical System and Components

7. Mount the brush holder to rear of starter frame. Install the four brushes into the corresponding slots. Then carefully work (set) each of the four brush springs into position behind the brushes. Slide the rubber insulating grommet onto the small corresponding plastic tab on frame. See Figure 8-64.

Figure 8-66. Tool on end of Armature.

10. Carefully slide the frame with the brush plate assembly down over the tool and onto armature and drive end cap, aligning the cutout with lever section (on top). The rubber insulating grommet should also be up. See Figure 8-67.

Figure 8-64. Mounting Brush Holder to Frame.

8. Position the insulator over the brushes and springs. Hold it firmly in place so the springs do not come out. See Figure 8-65.

Figure 8-65. Holding Insulator in Place.

9. Stand the armature/drive end cap assembly on end so the commutator end is up. Place brush/ armature installation tool over the end of armature shaft until it rests against the commutator. See Figure 8-66.

NOTE: Maintain pressure on the insulator while

installing so the springs do not come out.

Figure 8-67. Installing Frame with Brush Plate Assembly.

11. Remove the tool and install the commutator end cap, aligning the cutout with the insulating grommet. See Figure 8-68.

8.34

Figure 8-68. Installing End Cap.

12. Install and tighten the two thru bolts.

Section 8

Electrical System and Components

14. Connect the braided (brush) lead to lower main solenoid terminal and secure with the loose hex flange nut. See Figure 8-70.

13. Make sure the dust cover is in place on solenoid. Install solenoid engaging the plunger end with the yoke of the drive lever. Check by pulling solenoid towards the rear. Mount the solenoid to the starter using the two hex flange nuts. Tighten securely. See Figure 8-69.

Figure 8-69. Installing Thru Bolts.

Figure 8-70. Connecting Brush Lead.

8.35

Section 9

Disassembly

Section 9

Disassembly

WARNING: Accident al Starts!

General

Clean all parts thoroughly as the engine is disassembled. Only clean parts can be accurately inspected and gauged for wear or damage. There are many commercially available cleaners that will quickly remove grease, oil, and grime from engine parts. When such a cleaner is used, follow the manufacturer’s instructions and safety precautions carefully.

Typical Disassembly Sequence

The following sequence is suggested for complete engine disassembly. The sequence can be varied to accommodate options or special equipment.

1. Disconnect spark plug lead.

2. Turn fuel shut-off valve to off position.

3. Drain oil from crankcase.

4. Remove muffler and heat shield assembly.

5. Remove air cleaner assembly.

6. Remove fuel tank and fuel tank support.

7. Remove external governor, throttle, and choke linkage.

8. Remove carburetor.

9. Remove retractable starter.

10. Remove blower housing.*

11. Remove right fuel tank bracket, switch bracket, electric starter, and housing/cover panel assembly.

12. Remove left fuel tank bracket.

13. Remove governor lever and throttle linkage.

14. Remove valve cover/breather, air shroud, cylinder head assembly, and push rods.

15. Remove flywheel.

16. Remove ignition module.

17. Remove stator and protective shield.

18. Remove reduction assembly.

19. Remove closure plate.

20. Remove balance shaft assembly.

21. Remove camshaft and valve tappets.

22. Remove connecting rod with piston and rings.

23. Remove crankshaft.

24. Remove governor cross shaft.

25. Remove oil seals and bearings.

* Loosening/removing the electric starter cover panel

will provide access to upper housing mounting screw.

Disconnect Spark Plug Lead

1. Disconnect the lead from the spark plug. See Figure 9-1.

NOTE: Pull on boot only, to prevent damage to spark

plug lead.

Figure 9-1. Disconnecting Spark Plug Lead.

9.1

Section 9 Disassembly

Turn Fuel Shut-Off Valve to Off Position

Figure 9-4. Removing Muffler.

Figure 9-2. Fuel Shut-Off Valve.

Drain Oil From Crankcase

1. Remove one of the oil drain plugs and one of the oil fill caps.

Drain Plug

Figure 9-3. Oil Drain Plug.

2. Allow ample time for the oil to drain from the crankcase.

3. Remove the exhaust gasket from the outlet.

Remove Air Cleaner Assembly

Remove the air cleaner components from the air cleaner base as outlined in Section 4.

Remove the air cleaner base from engine as follows:

1. Remove the hex flange screw(s) securing the air cleaner base to the mounting bracket(s), based on the specific model involved. See Figures 9-5, 9-6, and 9-7.

3. On engines with a 2:1 reduction system, tip the engine toward the flywheel to drain most of the oil out of the reduction housing; then drain out of the crankcase.

Remove Muffler and Heat Shield Assembly

1. Remove the hex nuts from the exhaust studs and the hex flange screw from the muffler bracket.

2. Remove the muffler assembly from the exhaust outlet.

9.2

Figure 9-5. CS4, CS6 Air Cleaner Base.

Figure 9-6. CS8.5 (spec. 92xxxx), CS10, and CS12 Air Cleaner Base.

Section 9

Disassembly

Remove Fuel Tank

1. Make sure the fuel tank is empty. If the fuel shutoff valve is mounted directly to tank, close the valve. See Figure 9-2.

2. Loosen the clamp and disconnect the fuel line from the outlet of shut-off valve (fuel tank mounted valves) on CS4, CS6, CS8.5 (spec. 92xxxx), CS10, and CS12 engines. See Figure 9-9. On the CS8.5 (spec. 95xxxx) loosen the clamp and disconnect the fuel line from the inlet of the shut-off valve (blower housing mounted valves). See Figure 9-10.

Figure 9-7. CS8.5 (spec. 95xxxx) Air Cleaner Base.

2. Remove the two hex flange nuts securing the base to the carburetor mounting studs.

3. Disconnect one end of the breather hose from the valve cover or air cleaner base.

4. Pull the air cleaner base off the studs.

Figure 9-9. Disconnecting Fuel Line on CS4, CS6, CS8.5 (spec. 92xxxx), CS10, and CS12.

Figure 9-10. Disconnecting Fuel Line on CS8.5 (spec. 95xxxx).

3. Remove the four fuel tank mounting screws and lift off the fuel tank assembly.

Figure 9-8. Removing Air Cleaner Base.

9.3

Section 9 Disassembly

4. On CS8.5 (spec. 95xxxx) remove the five screws and washers securing the fuel tank support to the crankcase, and the single screw into the throttle control bracket. Lift off the fuel tank support. See Figure 9-11.

Figure 9-11. CS8.5 (spec. 95xxxx) Fuel Tank Support.

Figure 9-13. Loosening Governor Lever.

Remove External Governor, Throttle, and Choke Linkage

1. Carefully lift up and unhook the choke link and spring from the choke lever on the carburetor (CS8.5, CS10, and CS12 only). The choke link may stay connected on CS4 and CS6 engines.

Figure 9-12. Disconnecting Choke Link and Dampening Spring from CS8.5-CS12 Carburetor .

2. Loosen the hex flange screw securing the governor lever to the governor shaft.* Mark which hole location the governor spring is in. Lift off the governor lever with throttle linkage and spring attached, unhooking the governor spring from the throttle lever. Unhook the throttle linkage and dampening spring from the carburetor throttle shaft.

Figure 9-14. Removing Governor Lever and Linkage.

3. On CS8.5 (spec. 95xxxx) remove the single hex flange screw securing the throttle control bracket to the crankcase. See Figure 9-15.

Figure 9-15. Removing Control Bracket on CS8.5 (spec. 95xxxx).

9.4

Remove Carburetor

WARNING:

Gasoline may be present in the carburetor and fuel system. Gasoline is extremely flammable, and its vapors

can explode if ignited. Keep sparks, open flames and other sources of ignition away from the engine.

1. Remove the air cleaner base gasket from the two mounting studs.

2. Pull the carburetor outward and off the mounting studs.

3. Remove the outer gasket, spacer block, and inner gasket from the studs.

Section 9

Disassembly

Figure 9-17. Removing Carburetor Without Governor Lever Removal.

Remove Retractable Starter

1. Remove the hex flange screws securing the retractable starter to the blower housing. See Figure 9-18.

Figure 9-16. Removing Carburetor, Gasket s, and Spacer.

*If you want to remove the carburetor without

disturbing the governor lever mounting, proceed as follows.

1. Gently hold the governor lever in the full throttle

(left/clockwise) position.

2. Pull the carburetor outward and off the mounting studs. Tilt the carburetor and disconnect the throttle link and dampening spring from the throttle lever. See Figure 9-17.

Figure 9-18. Removing Starter Mounting Screws.

9.5

Section 9 Disassembly

Remove Blower Housing

1. Remove the hex flange screws securing the blower housing. The screw in the upper righthand position may also secure a ground lead on some models. See Figures 9-20 and 9-21.

NOTE: On models with electric starters,

loosening or removing the starter cover panel mounting screws will allow easier access to the screw in the upper righthand position.

Mounting Screws

Figure 9-21. Cover Panel Mounting Screws.

Not on CS8.5 (spec. 95xxxx)

Figure 9-19. CS8.5, CS10, and CS12 Blower Housing Screws.

Figure 9-20. CS4, CS6 Silver Screw with Ground Lead.

Upper Mounting Screw

Figure 9-22. CS8.5 (spec. 92xxxx), CS10, and CS12 Upper Right-Hand Mounting Screw.

2. Pull the blower housing off.

Figure 9-23. Removing the Blower Housing.

9.6

Remove Right Fuel Tank Bracket (if so equipped), Switch Bracket, Electric Starter, and Housing/Cover Panel Assembly

1. Disconnect the wiring harness bullet connectors for the oil sentry and ignition module. Remove the mounting screw securing the ground lead. See Figures 9-24 and 9-25. Disconnect the rectifier-regulator lead connections if used.

Section 9

Disassembly

Figure 9-26. CS4, CS6 Right T ank Bracket Mounting Details.

Figure 9-24. CS8.5 (spec. 92xxxx), CS10, and CS12 Ground Lead Location.

Figure 9-25. CS8.5 (spec. 95xxxx) Ground Lead Location.

2. Remove the two front fuel tank bracket (not used on CS8.5 [spec. 95xxxx]) mounting screws, attaching the throttle lever mechanism, switch and oil sentry light bracket. On electric start engines the electrical control panel housing will also be included. Note the washer used on PTO side screw only. See Figure 9-31.

Figure 9-27. CS8.5 (spec. 92xxxx), CS10, and CS12 Right T ank Mounting Bracket Details.

Electric Start Engines Only

3. Remove the two screws securing the control panel and mounting bracket for the electrical components. See Figure 9-28.

Figure 9-28. Removing Control Panel Screws.

9.7

Section 9 Disassembly

4. Remove the two electric starter mounting bolts. See Figures 9-29 and 9-30.

Figure 9-29. Removing Inertia Drive Starter Mounting Bolts.

Figure 9-31. Inertia Drive Starter and Control Panel Removed.

Starter Mounting Bolts

Figure 9-30. Starter Bolt s on Models with Solenoid Shift Starters.

5. Remove the starter motor, wiring harness and control panel housing from the engine. Components may be further disassembled if required. See Figures 9-31, 9-32, and 9-33.

Figure 9-32. Solenoid Shift St arter and Control Panel Removed.

Figure 9-33. Control Panel and R.H. T ank Bracket.

9.8

Remove Left Fuel Tank Bracket

1. Remove the left fuel tank mounting bracket by removing the two screws. Figure 9-34 and 9-35. Washers are used on the CS4 and CS6 only.

Figure 9-34. CS4, CS6 Left Side Tank Mounting Bracket Details.

Section 9

Disassembly

Figure 9-36. Removing Valve Cover Screws on Models with Attached Support Bracket.

Figure 9-35. CS8.5 (spec. 92xxxx), CS10, and CS12 Left Side Tank Mounting Bracket Details.

Remove Valve Cover/Breather, Air Shroud, Cylinder Head Assembly, and Push Rods

1. Remove the four hex flange screws securing the valve cover. The air cleaner support bracket (CS8.5-12) may be mounted off two of the screws or directly to cylinder head. Remove the support bracket and note the locations of all the screws. See Figures 9-36 and 9-37.

Support Bracket Screws

Figure 9-37. Support Bracket Screws on CS8.5 (spec. 95xxxx).

2. Remove the valve cover and gasket from the cylinder head. See Figure 9-38. The breather assembly is inside the valve cover.

Figure 9-38. Valve Cover, Gasket, and Air Shroud Removed.

9.9

Section 9 Disassembly

3. Lift off the air shroud from the cylinder head. CS4 and CS6 air shrouds have one mounting screw which must be removed. See Figure 9-39.

Figure 9-41. Cylinder Head and Gasket Removed.

Mounting Screw

Figure 9-39. CS4, CS6 Mounting Screw Location.

4. Remove the four hex flange screws securing cylinder head. Remove the cylinder head, dowel pins (2), push rods, and cylinder head gasket.

NOTE: Mark the push rods so they will be

reinstalled in the same location.

Figure 9-40. Remove Cylinder Head Mounting Screws.

Disassemble Cylinder Head

1. Remove the spark plug.

2. Slide the rocker shaft out and remove the rocker arm assemblies on CS8.5-12 engines. Mark or note position of each part, if it is to be reused.

Figure 9-42. CS8.5 (spec. 92xxxx), CS10, and CS12 Removing Rocker Arms and Sp ark Plug.

3. Using a valve spring compressor, remove the valves by compressing the valve springs and removing the keepers. See Figure 9-43.

9.10

Section 9

Disassembly

Remove Flywheel

NOTE: Whenever possible, an impact wrench should

be used to loosen the flywheel retaining nut. A flywheel strap wrench, or an approved holding tool (see Section 2) may also be used to hold the flywheel when loosening or tightening the flywheel retaining nut.

Always use a puller to remove the flywheel from the crankshaft. Do not strike the flywheel or crankshaft as these parts could become cracked or damaged.

Figure 9-43. Disassembling Valve Assemblies.

4. Remove and replace the intake valve stem seal whenever the cylinder head is serviced or diassembled. See Figure 9-44.

Figure 9-44. Removing Intake Valve Stem Seal.

5. If the cylinder head is being replaced, the carburetor mounting studs can be removed by using the air cleaner base nuts locked together. See Figure 9-45.

NOTE: Some electric start flywheels require the

ignition module be taken off first, or loosened, to remove the flywheel from crankshaft. See Figure 9-46. Perform "Remove Ignition Module" prior to Step 1 if applicable.

Figure 9-46. Electric Start Flywheel/Module Configuration (some models).

1. Remove the flywheel retaining nut, washer, and drive cup. See Figures 9-47 and 9-48.

Figure 9-45. Removing Carburetor Mounting Studs.

Figure 9-47. Removing Flywheel Nut using an Impact Wrench.

9.11

Section 9 Disassembly

Figure 9-48. Removing Flywheel Nut Using Holding Tool.

2. Remove the flywheel from the crankshaft using a puller. See Figure 9-49 and 9-50.

Remove Ignition Module

1. Remove the two hex flange screws securing the ignition module to the crankcase. See Figure 9-51.

Figure 9-51. Removing the Ignition Module Screws.

Remove Stator and Protective Shield (If So Equipped)

1. Remove the mounting screw and protective shield over the stator leads. See Figure 9-52.

Figure 9-49. Using Puller to Remove Flywheel on CS8.5-CS12.

Figure 9-50. Use External T ype Puller to Remove Flywheel on CS4, CS6.

3. Remove the flywheel key from keyway.

Style 1

Style 2

Figure 9-52. Stator and Protective Shield.

9.12

2. Remove the four hex flange shoulder screws securing the stator to the crankcase. Remove the stator and pull the wires through the opening in the casting. See Figure 9-53.

Figure 9-53. Removing Mounting Screws and Stator.

Section 9

Disassembly

Figure 9-55. Removing Reduction Housing Screws on CS8.5-CS12.

3. Pull the reduction housing off the closure plate.

Remove Reduction Assembly (If So Equipped)

2:1 Reduction Assembly

1. Remove any drive coupling and the key from the reduction assembly output shaft. Clean the shaft and keyway of any burrs/damage.

2. Remove the mounting bolts securing the reduction system housing onto the crankcase. Place a flat pan or towel under the housing to catch any remaining oil. See Figures 9-54 and 9-55.

Figure 9-56. Removing Reduction Housing on CS4, CS6.

Figure 9-54. Removing Reduction Housing Screws on CS4, CS6.

Figure 9-57. Removing Reduction Housing on CS8.5-CS12.

9.13

Section 9 Disassembly

4. Remove the screw and washer securing the crankshaft sprocket/gear.

Figure 9-58. Removing Screw from Crankshaft on CS4, CS6.

Figure 9-60. Removing Sprockets and Chain on CS4, CS6.

Figure 9-59. Removing Screw from Crankshaft on CS8.5-CS12.

5. Remove the reduction components.

a. On CS4 and CS6, leave the chain intact, and

pull out the two sprockets as an assembly. See Figure 9-60. Note the position of the wave washer and remove it from the output shaft. Also remove the thrust washer from the end of the crankshaft. See Figure 9-61.

Figure 9-61. Thrust Washer Behind Crank Sprocket on CS4, CS6.

b. On CS8.5-12, remove the crankshaft gear,

counter gear, and output shaft/gear assembly. See Figure 9-62.

Figure 9-62. CS8.5-CS12 Disassembled Reduction Assembly.

9.14

6. Check the reduction system bearings for wear or excessive play. See Figure 9-63. If bearing removal is required, use an internal bearing puller to remove the housing bearings. An arbor press should be used for removal of the others.

Figure 9-63. Checking Bearing Play .

Section 9

Disassembly

Figure 9-65. Removing Cover from Reduction Housing.

4. Remove the ring gear/output shaft assembly. See Figure 9-66.

6:1 Reduction Assemblies, CS4 and CS6

1. Remove any drive coupling and the key from the reduction output shaft. Clean the shaft and keyway of any burrs/damage.

2. Remove the four reduction cover mounting screws. Use a flat pan to catch oil when the screws are removed and the cover is separated. See Figure 9-64.

Figure 9-64. Loosening Reduction Housing Cover Screws.

Figure 9-66. Removing Ring Gear/Shaft.

5. If the reduction housing requires removal from the closure plate, remove the four mounting screws and separate the two castings.

3. Remove the cover from the reduction housing assembly.

Figure 9-67. Removing Housing Mounting Screws.

9.15

Kohler HYDRO 12.75, CS4, CS8.5, CS10, CS12 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

Section 1

Section 2

Section 3

Section 4

Section 5

Section 6

Section 7

Section 8

Section 9