425 no governor

oldnslo · Jun 13, 2016

Friend has 425 the just started to run away. We have checked & rechecked all of the throttle and governor linkage finding nothing binding or broken. Hve checked and checked the governor adjustment (everything full CCW) All springs in place but engine still will not stay at an idle unless you physically hold the throttle plate closed. Engine runs smooth when holding the throttle linkage, accelerates smoothly, etc.

Is the governor fly weight shaft supposed to move up and down approx 1/8"?

Any other thoughts or suggestions on what to check?

Richard001 · Jun 13, 2016

It would help to know what engine is in the machine.

Richard

beenthere · Jun 14, 2016

Engine should be Kawasaki, FD620D, K Series.

Check linkage, governor spring, and may be the gov. gear assembly is binding or broken.

Getting a hold of a service tech manual may be a good investment at this point.

oldnslo · Jun 14, 2016

Yes engine is FD620 K series.

Is it possible that the governor gear is stripped or broke or possibly the early signs of the plastic cam egar failing? It does not feel like the fly weights are even trying to turn the governor shaft.

I have the JD service manual TM1517 but it is vague on how the fly weight is driven.

I don't want to pull the engine and remove the crankcase cover if there is another possible cause.

Fairly sure not fuel related since engine starts and runs smoothly and closing the choke partially causes the engine to run rich.