Originally Posted by Cesco
According to Brutus1967 the pressure sensing hole on the front of the carb is the cause of the oscillating idle rpm's. Is there any confirmation for this? Is the idle better when the prop is replaced with a disk?
I was not referring to the hole in the carb, I am assuming the pump has a pressure sensing hole, otherwise it could never function as a pressure regulator. It is that hole I was referring to, and the reason I was thinking about it, was because some people report the engine is running OK, others are reporting it is not, and that pump/regulator is subject to "owners view to correct installation" so it is possible, that results vary from owner to owner because of pressure fluctuations on this hole, caused by differences in installing it.