Should the engine overspeed, the magnetic pick up will
close the circuit to the fuel shutoff solenoid and stop the
The shutoff switch can be checked for proper operation
at 75% overspeed condition:
1. Determine the full load RPM of the engine from the
serial number plate.
2. Operate the engine at the corresponding speed
shown in the OVERSPEED TEST RPM Column of the
FULL LOAD RPM
OVERSPEED TEST RPM
ACTUAL OVERSPEED RPM
The Overspeed Test RPM is slower than the Full Load
FULL LOAD RPM x .885 = OVERSPEED TEST RPM
3. While maintaining test RPM, push and hold the
VERIFY button. The engine should stop.
If the engine does not stop at the specified test RPM,
contact your Caterpillar dealer.
As the engine stops, the yellow light (2) will go on.
The RESET button (1) must be pushed before starting
If the engine is equipped with a CAT Generator Set
Control Panel, the devices on the panel must be reset: