Chapter 9. Troubleshooting - Tecumseh HH100 Handbook

CHAPTER 9. TROUBLESHOOTING

TROUBLESHOOTING
Below is a list of common problems and remedies. Follow a uniform procedure to locate and eliminate
the causes.
Cause
A. ENGINE FAILS TO START OR STARTS WITH DIFFICULTY
No fuel in tank.
Shut-off valve closed.
Obstructed fuel line.
Tank cap vent obstructed.
Water in fuel.
Engine over-choked.
Improper carburetor adjustment.
Loose or defective magneto wiring.
Faulty ignition unit.
Spark plug fouled.
Spark plug porcelain cracked.
Poor compression.
No spark at plug.
Electric starter does not crank engine.
B. ENGINE KNOCKS
Carbon in combustion chamber.
Loose or worn connecting rod.
Loose flywheel.
Worn cylinder.
Improper Magneto Timing.
Improperly set ignition unit.
Excessive main bearing end play.
Remedy
Fill tank with clean, fresh fuel.
Open valve
Clean fuel screen and line. If necessary, remove
and clean carburetor.
Open vent in fuel tank cap.
Drain tank. Clean carburetor and fuel lines. Dry
spark plug electrodes. Fill tank with clean, fresh
fuel.
Close fuel shut-off and pull starter until engine
starts. Reopen fuel shut-off for normal fuel flow.
Adjust carburetor.
Check magneto wiring for shorts or grounds;
repair if necessary.
Check ignition unit. Solid State.
Check points, timing on standard ignition units.
Clean and regap spark plug.
Replace spark plug.
Check compression.
Disconnect ignition cut-off wire at the engine. Crank
engine. If spark at spark plug, ignition switch, safety
switch or interlock switch is inoperative. If no spark,
check magneto. Check wires for poor connections,
cuts, or breaks.
See 12 volt starter trouble shooting chart page.
Remove cylinder head and clean carbon from
head and piston.
Replace connecting rod.
Check flywheel key and keyway; replace parts if
necessary. Tighten flywheel nut to proper torque
(See Table of Specifications).
Recondition cylinder or replace.
Time ignition.
Check ignition unit.
Readjust to correct crankshaft end play.
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