47 B revs up & down

Gary47B · Jul 28, 2015

My B has run great for years but on hot days it will rev up and down and sometimes stall. I think this could be a governor issue. Can anyone explain how the governor works? I checked for vacuum leaks around the manifold. I rebuilt the carb several times. Thanks, Gary

old · Jul 28, 2015

Is the anti-surged spring still on it that hooks the the front manifold stud?? If not that is where your problem is

Gary47B · Jul 29, 2015

the spring is in place. You can watch the rod connected to the carb move back and forth with tension on the spring. This makes me think it must be the governor.

Dick L · Jul 29, 2015

It will not be a governor problem. It shows you governor is working properly. When it does not have enough fuel to maintain your set rpm's the governor is opening up the throttle plate to let more gas. When it gets the gas and the rpm's come up the governor closes the throttle plate to hold the rpm's to your setting and you are not getting enough fuel to keep it at the set rpm's. That then slows the rpm's and governor again opens the throttle plate. That is the way the governor is suppose to work. You will find the problem in the linkage, carburetor or fuel supply from the tank. I am not sure what hot weather has to do with it.
First look for binding or rubbing of the linkage. Sometimes it can be found rubbing under the water outlet neck on the head. If it does not do it all the time in most likely in not out of adjustment linkage. It can be floating stuff in the carburetor or fuel delivery system.

47 B revs up & down

Gary47B

New User

old

Well-known Member

Gary47B

New User

Dick L

Well-known Member

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