What Is This On My Governor?

[9GT]

I have a McCauley DC 290 governor that has some sort of adjustment on top of it as seen below with the jam nut. I can not find a manual for it on-line and when I contacted McCauley and asked about a manual, there response was to take it to one of the authorized service centers if there were any problems with it. Anyone have any idea what this adjustment is for? The engine is an IO-540 V4A5 that came out of a late model Maule.

 

[Titan-Xpert]

I believe that is the internal oil pressure adjustment, these governors have a built in pump to increase pressure to the level need to operate the prop. My experience has been that if this pressure is set low the prop response is slow and if the pressure is set high it responds very rapidly. This adjustment is normally done at the time of governor overhaul.

 

[9GT]

Thanks Bobby!

 

[paul mosher]

goop

I thought you were asking about all the goop on it.

 

[planenutz]

Yep, this is the Governor's Oil Pressure Relief Valve. This is often a simple ball-valve arrangement with a spring behind it and it sets up the internal working pressure of the governor. Typically the working pressure is around 210-320 PSI however this varies depending on the governor manufacturer, the model and the installation requirements. In your case it is very likely that the working pressure is 290 PSI but without the entire part number of the governor its not possible to tell.

In essence - and as "Titan-Xpert" has already indicated - this adjustment is set at the factory or overhaul shop by running the governor on a test rig and shouldn't be adjusted in the field.


Cheers,

Mike