Onan MJA Series Service Manual page 19

17 TROUBLE-SHOOTI CHART
TROUBLE-SHOOTING CHART 1, THE ENGINE (Cont.)
TROUBLE
I
POSSIBLE CAUSE
I
REIVlEDY
Light pounding Loose connecting rod Replace bearings.
knock bearing.
Low oil supply. Add oil - check for
cause of low oil, Sect
3.5.
Oil badly diluted. Replace oil.
Pinging sound Carbon in cylinder. Remove carbon.
when engine is
suddenly or Spark too early. Adjust breaker points.
heavily loaded Retime spark if nec­
essary. Sect3.3.3
and 3.3.4.
Wrong spark plug. Install correct spark
plug Sect 3.3.5.
Valve hot. Adjust valve clearance.
Sect 3.7.
L
......
,
Fuel stale or low octane. Use good, fresh fuel.
Lean fuel mixture. Clean and adjust car ­
buretor. Sect3.2.5.
Engine hot. Check air circulation.
Engine overheats Defective ventilating Check ventilators and
(See Sect 3.1.2) system. ducts.
Defective installation. Inspect complete instal­
lation including ducts
etc.
Improper lubrication. Check oil system.
Late ignition timing. Retime ignition.
Fuel mixture too lean. Adjust carburetor, Sect
3.2.5.
Generator overloaded. Inspect electrical load.