JLG 40H Service Manual - Manual (Page 120)

SECTION 3 - TROUBLESHOOTING
3-8
– JLG Lift – 3120240
Engine will not accelerate above low speed. Damaged wiring on speed control switch or high
engine solenoid.
Speed control switch not functioning properly.
High engine solenoid not functioning properly.
High engine circuit breaker not functioning prop-
erly.
Switch not functioning properly or improperly
adjusted.
Excessive load on engine.
Engine worn badly.
Engine improperly timed.
Dirty fuel filter (diesel).
Fuel line pinched (diesel).
Throttle governor not working properly.
Repair, replace wiring.
Replace switch.
Repair or replace solenoid.
Replace circuit breaker.
Adjust, repair, or replace horizontal limit switch.
Reduce load.
Rebuild engine.
Time engine.
Replace filter.
Replace fuel line.
Repair or replace governor.
Engine surges. Governor not adjusted properly. Correctly adjust governor.
TROUBLE PROBABLE CAUSE REMEDY