Kohler M20 Generator Set

⚠ Do not force tapered adjusting needles

Tools: Tachometer, Screwdriver

1. Stop engine; turn adjusting needles in clockwise until lightly bottomed.
2. Set preliminary settings: main fuel 2-1/2 turns, idle fuel 1 turn out.
3. Run engine at half throttle 5-10 minutes to warm up.
4. Final main fuel: set needle midway between rich and lean settings.
5. Final idle fuel: set needle using same procedure; idle speed not to exceed 1500 RPM.
6. Set idle speed to 1200 RPM (plus or minus 75) with idle speed screw.

⚠ Piston must be at TDC of compression stroke to measure clearance

Tools: Flat feeler gauge

1. Remove air cleaner, valve covers, breather, and spark plugs.
2. Rotate flywheel and observe tappets; measure clearance on cylinder with no movement.
3. Measure with a flat feeler gauge (engine cold).
4. Rotate flywheel 360 degrees and measure remaining cylinder.
5. If clearance too small, grind valve stems; if too large, replace valves.

⚠ Do not connect 12 volts to ignition module; it can burn out

Tools: .014 in feeler gauge or shim stock

1. Install module and hex flange screws to bracket; tighten slightly.
2. Insert a .014 in feeler gauge between magnet and module.
3. Loosen screw so magnet pulls module against feeler gauge; tighten securely.
4. Remove feeler gauge; final air gap should be .008/.012 in.
5. Rotate flywheel and check magnet does not strike module.
6. Install kill lead to kill terminal and reinstall blower housing.

1. Drain oil while engine is still warm.
2. Remove oil drain plug and dipstick; tilt engine toward drain hole.
3. Reinstall drain plug securely.
4. Fill with proper oil to the F mark on dipstick.
5. Make sure engine is level when filling and checking.

1. Drain crankcase oil, then remove old filter.
2. Apply thin coating of oil on rubber seal of new filter.
3. Turn filter clockwise until seal contacts adapter, then tighten an additional turn.
4. Add an additional 1/2 pint of oil for filter capacity.
5. Start engine and check for and correct any oil leaks.

1. Make sure engine is stopped, level, and cool.
2. Clean area around dipstick before removing.
3. Remove dipstick and wipe oil off.
4. Reinsert dipstick fully and remove to check level.
5. Oil level must be up to but not over the F mark.
6. Add proper oil if low; recheck on dipstick.

⚠ Do not clean spark plugs with abrasive grit

Tools: Wire feeler gauge

1. Clean area around base of plugs before removing.
2. Remove plugs and check condition; replace if worn.
3. Check gap with wire feeler gauge and adjust to 0.035 in.
4. Reinstall into cylinder heads and torque to 10/15 ft lb.

Tools: Wooden or plastic scraper, Torque wrench

1. Remove cylinder head baffles and cylinder heads.
2. Clean away combustion deposits using a wooden or plastic scraper.
3. Reinstall cylinder heads using new gaskets.
4. Torque fasteners in increments to 15/20 ft lb in the specified sequence.

1. Remove precleaner from paper element; wash in warm water with detergent.
2. Rinse thoroughly; squeeze out excess water (do not wring); air dry.
3. Saturate precleaner in clean, fresh engine oil.
4. Squeeze out excess oil.
5. Reinstall precleaner over paper element.

1. Clean exterior surfaces of engine.
2. Change oil and filter while engine is still warm.
3. Empty fuel system or treat gasoline with stabilizer; run 2-3 minutes.
4. Remove spark plugs and add one tablespoon engine oil into each hole.
5. Crank engine two or three revolutions; store in a clean, dry place.

1. Remove precleaner (if equipped), element cover seals, element cover, and element.
2. Replace a dirty, bent, or damaged element with a new genuine Kohler element.
3. Reinstall cleaned and oiled precleaner over paper element.
4. Reinstall paper element, element cover, and seals.
5. Install cover and wing nuts; tighten 1/2 to 1 full turn after contact.

⚠ Use only Kohler starter drive lubricant; other lubricants can cause sticking

1. Remove dust cover, stop nut, stop gear spacer, spring, dust cover spacer, and drive pinion.
2. Clean drive shaft splines with solvent and dry thoroughly.
3. Apply Kohler starter drive lubricant (Part No. 52 357 01) to splines.
4. Apply Loctite No. 271 to stop nut threads and reassemble in reverse order.
5. Torque stop nut to 160 in lb.