5464-646 WOODWARD

Governor faults are usually revealed as speed variations of the prime mover, 

however, it does not necessarily follow that all speed variations indicate governor 

faults. Troubleshoot the governor to localize a problem before attempting 

disassembly and repair. 

Use the following Troubleshooting Diagram to troubleshoot your governor. See 

Chapter 6, Governor Calibration, or refer to the engine manufacturer’s 

specifications for engine calibration. 

Be prepared to make an emergency shutdown when starting the 

engine, turbine, or other type of prime mover, to protect against 

runaway or overspeed with possible personal injury, loss of life, or 

property damage. 

Problem Question Procedure

Engine cranks, 

but governor 

output shaft 

doesn’t move 

from minimum 

position. 

With manual 

assistance, can 

the governor 

output shaft be 

easily moved 

towards 

maximum while 

cranking? 

YES—

1. Is governor filled with oil? 

2. Is the rotation of the pump set correctly? 

3. Have you cranked the engine for at least 10 seconds to allow the 

governor time to develop pressure? 

4. Is the drive shaft connected? 

5. Is the oil viscosity greater than 50 SUS? 

6. Is the cranking speed too low? 

NO—

1. Are any shutdown devices activated or incorrectly adjusted? 

2. Is speed setting above cranking speed? 

3. Is linkage free from excessive friction? 

4. Is load limit set at zero? 

5. If fuel limiter is used, is it correctly adjusted? 

Governor opens 

fuel, but is slow 

and sluggish. 

 1. Are shutdowns properly adjusted? 

2. Is the governor oil viscosity less than 50 SUS, or above 3000 

SUS? 

3. Is the need valve closed too far? 

4. Is linkage to the engine free? 

Governor opens 

fuel, but only part 

way. 

 1. Is load limited adjusted properly, and set out of the way? 

2. Is there adequate manifold pressure? [applies to fuel limit type 

governors] 

3. Is fuel stop on engine adjusted properly? 

4. Is fuel stop in governor set properly? 

5. Is fuel linkage free? 

Governor opens 

fuel and prime 

mover starts, but 

trips out on 

overspeed. 

 1. Is the linkage sticky? 

2. Is the linkage properly adjusted? 

3. Is the overspeed trip set properly? 

4. Is the needle valve closed too far? 

5. Is the governor speed setting too high? 

System oscillates 

and is unstable. 

Check the following: 

1. Is droop properly set? 

2. Is the needle valve correctly adjusted? 

3. Is linkage sticky or worn?