69.
Engine Idles Improperly
Possible remedy
Probable case
Adjust carburetor (par. 10).
Carburetor fuel and air mixture not properly adjusted.
Adjust the idling speed screw (par. 106).
Idling speed too slow.
Adjust timing (par. 182e). See note in paragraph 55.
Timing incorrect.
Inspect, remove, clean, and replace spark plugs (par.
Spark plug fouled.
Clean and adjust magneto points (par. 116b).
Magneto points dirty.
70.
Magneto Fails to Spark
Possible remedy
Probable cause
Adjust breaker points (par. 116e).
Breaker points not adjusted.
Adjust magneto timing (par. 116g).
Magneto timing incorrect.
Replace breaker points (par. 116b).
Breaker points defective.
Replace rotor (par. 116).
Rotor defective.
Replace coil (par. 116).
Coil defective.
Replace condenser (par. 116).
Condenser defective.
Clean, tighten, or replace terminals.
Terminals loose or grounded.
71.
Oil Pressure Drops
Possible remedy
Probable cause
Check and add oil. Refer to LO 5-1186.
Lack of oil
Inspect and clean oil line.
Oil line clogged.
Clean filter housing and replace element (par. 123).
Oil filter clogged or dirty.
Fill the crankcase with proper grade of oil. Refer to LO
Oil too thin.
5-1185.
Inspect, adjust, or replace (par. 197). See note in
Pressure relief valve broken or damaged.
Replace oil pump (par. 196). See note in paragraph 55.
Oil pump worn out.
Replace bearings and rings (par. 178). See note in
Bearings and piston rings worn out.
72.
Oil Pressure Rises Too High
Possible remedy
Probable cause
Fill the crankcase with proper grade of oil. Refer to LO
Oil too thick.
5-1185.
Inspect, adjust, or replace pressure relief valve (par.
Pressure relief valve broken or damaged.
197). See note in paragraph 55.
73.
Spark Plugs Fail to Spark
Possible remedy
Probable cause
Replace spark plugs (par. 117).
Spark plugs defective.
Adjust magneto (par. 116).
Magneto out of adjustment.
Tighten or connect the spark plug cables.
Spark plug cables loose or disconnected.
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