Reasons for Unstable Speed of Diesel Generator Set

1. Idle speed is not smooth
It means that diesel generator set operates suddenly quickly and slowly in the idle speed, but the regularity is not strong, and there are jitter. Diesel generator set is easy to flameout in the rapid deceleration, shift or load, which is mostly cause by governor failure. The main reasons are the followings:
(1) Poor idle spring elasticity or improper adjustment
(2) Improper stable spring adjustment
(3) Poor low-pressure oil supply or containing water and air
(4) The camshaft bearing of fuel injection pump support cam wears too much
(5) Uneven fuel supply in fuel injection pump, incorrect oil supply timing or poor fuel injection
(6) Insufficient cylinder compression

2. “Travel”
The so-called “travel” refers to longer and more regular “fast sometimes and slow sometimes” phenomenon appears in the low speed and medium speed range of the diesel generator set, which is caused by speed regulating response lagging behind actual speed change. The main reasons are the followings:
(1) The internal lever of governor is loose due to the wear of pin hole
(2) Fuel supply gear rod is not flexible enough
(3) Improper stable spring adjustment