Chapter 13 Troubleshooting - Tecumseh VLV Technician's Handbook

The following charts can be helpful in locating the most common troubles associated with gasoline engines; Pos-
sible causes and remedies are listed below. Refer to the appropriate sections in this Technician's Handbook for
further detail of procedures.
Cause
No fuel in tank.
Shut-off valve closed.
Tank cap vent obstructed.
Obstructed fuel line.
Engine flooded.
Water in fuel.
Spark plug fouled.
No spark at plug.
Spark plug porcelain cracked.
Electric starter does not crank engine.
Loose or defective ignition wiring.
Incorrect timing.
Poor compression.
Loose flywheel.
Improper ignition timing.
Carbon in combustion chamber.
Loose or worn connecting rod.
Worn cylinder.
13-1
Chapter 13
Troubleshooting
Table 1. 4-Cycle Engine Troubleshooting Chart
Engine Fails to Start or Starts with Difficulty
Remedy and Reference
Fill tank with clean, fresh fuel.
Open valve.
Clean the vent or replace the cap.
Clean fuel screen and line. If necessary, remove and clean
carburetor.
Close fuel shut-off, if so equipped, and pull starter until engine
starts. Reopen fuel shut-off for normal fuel flow.
Drain tank. Clean carburetor and fuel lines. Dry spark plug
points. Fill tank with clean, fresh fuel.
Replace spark plug.
Check ignition air gap. If air gap is correct and there is no
spark at plug replace ignition.
Replace spark plug.
See 12 volt starter troubleshooting chart.
Check ignition wiring for shorts or grounds; repair if necessary
Flywheel key has sheared or partially sheared. Replace key.
Overhaul engine.
Engine Knocks
Check flywheel key and keyway; replace parts if necessary.
Tighten flywheel nut to proper torque.
Flywheel key has sheared or partially sheared. Replace
key.
Remove cylinder head and clean carbon from head and
piston.
Replace connecting rod.
Replace cylinder.
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