TESTING AND ADJUSTING
4. ENGINE SPEED DOES NOT HAVE STABILITY. (Cont.)
Rough Governor Drive
Worn splines and/ or high gear clearances can cause rough
governor drive. Inspect and replace parts as needed.
Governor can also be out of alignment with drive. Loosen
governor and adjust as needed for correct alignment with drive.
Make reference to Item 7.
Dirty Oil in Governor (Woodward UG-8)
Oil is decomposed and sludged slowing governor response.
Replace with new oil after flushing with diesel fuel. High
operating temperatures may require heavier viscosity oils.
Pneumatic (Air) Speed Setting Adjustment Wrong
If engine is equipped with pneumatic speed setting, improper
adjustment or excessive play in the governor linkage can be a
problem. Inspect and correct.
Power Piston Sticking
Governors on engines that have not been run for long periods
may develop rust in areas of the compensation pistons, etc.
causing instability. Oil varnish also causes parts to stick. Correct
by governor disassembly and cleaning.
Repair or replace governor.
Low Governor Oil Pressure
Check correct oil level. Oil pump relief valve does not seat.
Replace valve. Oil pump worn. Replace parts.
5a. ENGINE HIGH IDLE SPEED TOO LOW
Speed Setting Shaft Not Against High Idle Stop
Check speed control linkage and/or pneumatic controls for
restrictions. Make repairs or replacement as needed.
Incorrect Adjustment of High Idle
Governor speed setting shaft is against high idle stop and high
idle is too low. Make adjustment to correct high idle. Also, check
to make sure engine fuel setting is correct.
Speed Droop Adjustment Incorrect
Internal adjustable speed droop is set at the factory.
adjustment if necessary.