Flat topped vs grooved top governors?

[RustyKnuckles]

I notice that Cub governors on eBay are either "flat topped" or "grooved top." Can anyone enlighten me as to what the functional difference is, or which type goes with which years? I don't need this for any imminent repairs, just curious....

[RustyKnuckles]

Nobody knows ??

[SONNY]

I never noticed a different style! LOL! but didnt know there was one! now I gotta look at mine after 5 or 6 feet of snow melts away from them!--- so far I only see 1 muffler and sickle bar sticking out!-- dont know where the others are parked! thanks; sonny

[RustyKnuckles]

The parts that are either flat topped or grooved are the weights inside which fly out by centrifugal force. Can't be seen from the outside. I **suspect** that the grooved topped weights are later, but don't know for sure. The grooved weights look to weigh less than the flat topped ones, so that governor action would kick in at higher rpm. Or at least that is my guess.

[Barnyard]

Could it be the one governor is from a power unit?

[John *.?-!.* cub owner]

From my personal experience, the grove top he is referring to are from the later model C60 engines, such as 154 or late model cubs that ran at higher rpms. the weights are lighter, and as Barnyard said, I believe a similar weight may have been in a power unit. My loader cub has a power unit engien in it, but i do not remember ever having had the governor off to notice.

[jrenn]

My 56 lo-boy has a power unit engine in it so that might explain why it runs at a higher rpm than our other cubs