47
TROUBLESHOOTING
2 CYCLE ENGINE TROUBLESHOOTING CHART
Cause
Remedy and Reference
ENGINE FAILS TO START OR STARTS WITH DIFFICULTY
No fuel in tank
Fill tank with clean, fresh fuel with correct oil ratio.
Fuel shut-off valve closed
Open valve.
Obstructed fuel line
Clean fuel screen and line. If necessary, remove
and clean carburetor.
Tank cap vent obstructed
Open vent in fuel tank cap or replace cap.
Water in fuel
Drain tank. Clean carburetor and fuel lines. Dry
spark plug points. Fill tank with clean, fresh fuel.
Engine overchoked
Close fuel shut-off and pull starter until engine starts.
Reopen fuel shutoff for normal fuel flow immediately
after engine starts.
Improper carburetor adjustment
Adjust carburetor.
Loose or defective magneto wiring
Check magneto wiring for shorts or grounds; repair
if necessary.
Sheared or incorrect flywheel key or adapter sleeve
Replace with correct key or adapter sleeve.
Faulty Magneto
Check timing, point gap, and if necessary, overhaul
magneto.
Spark plug fouled
Clean and regap spark plug.
Crankcase seals and/or gaskets leaking
Replace seals and/or gaskets.
Spark plug porcelain cracked
Replace spark plug.
Poor Compression
Overhaul engine.
Exhaust ports plugged
Clean exhaust ports
ENGINE KNOCKS
Carbon in combustion chamber
Remove cylinder head or cylinder and clean carbon
from head and piston.
Loose or worn connecting rod
Replace connecting rod.
Loose flywheel
Check flywheel key and keyway; replace parts if
necessary. Tighten flywheel nut to proper torque.
Worn cylinder
Replace cylinder.
Improper magneto timing
Time magneto.
Summary of Contents for AH520 -
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