TM 55-4920-384-13&P
Ignition switch faulty
Replace switch.
Battery cable loose on armature relay
Tighten loose connections.
Carburetor flooded
Remove spark plugs and crank the
engine several times to drive out rich fuel mixture.
No ignition spark
Test the spark.
Spark plug defective
Clean and adjust or replace spark plug.
Magneto faulty
Repair or replace magneto contact point set.
Engine misses or runs erratically.
Carburetor gasket leaks
Tighten carburetor mounting bolts.
Replace gaskets if leak persists.
Spark Plug
Test spark, clean or replace if necessary.
Ignition wiring loose
Tighten ignition wire connections.
Spark gap incorrect
Measure and reset spark plug gap.
Magneto contact points pitted or
Clean, adjust, or replace contact
incorrectly adjusted
points.
Governor defective
Repair governor.
Engine stops suddenly.
Repair or replace fuel pump.
Fuel pump defective
Fuel line clogged
Remove and clean fuel line, replace if defective,
Magneto contact set defective
Replace defective contact set.
Hydraulic fluid temperature excessive
Allow fluid to cool.
Engine overheats.
Clean dust and dirt from cooling fins.
Cylinder cooling fins dirty
Magneto timed late
Time the magneto.
Air shroud partially removed from engine
Install the missing shroud.
Engine knocks or develops excessive
noise.
Magneto timing advanced too far
Time the magneto.
Remove and clean cylinder heads.
Carbon deposits on cylinder heads
4-6