Woodward Governor RPM Adjustments

[jaredyates]

Does anyone know if there is a correlation in max RPM and threads on the stop screw for a Woodward prop governor? For example, I'm currently getting 2600 RPM during a static runup. Is there a certain number of turns on the screw that will get me closer to 2700? It would be nice to not have to taxi back and forth between the ramp and the engine run area to do it by trial and error.

[Mark Goldberg]

Jared - there is a correlation like you asked for. But I don't know it. I would try 1/2 turn and see what that gives you. The good thing is that you are already close enough at 2600 rpm that you could take off & climb well. Mark

[Gavin Chester]

One full turn = 25 rpm on most governors.
Static rpm with governor set full fine ( adjuster screw backed off ) 25 - 100 rpm below redline.
Start with control about one inch pulled out and advance to check , to avoid over speed.
If you are not getting this , adjust the fine pitch stop on the propeller.
Best way to set the governor for max rpm is to fly it , set your control at the max rpm (you want) during an extended circuit, do not move it , land , adjust the screw to the stop , then safety wire it.

Note ! You can cheat these numbers a little and still be legal to get Max performance, most propellers give you a over speed time limit, before needing inspection !

[jaredyates]

Thanks Gavin! As I read your post and other info, I'm starting to think that I might leave it alone for now, and adjust after I can more comfortably test fly to validate the adjustments. As Mark points out, it's not going to be short on performance for my first flights anyway. I have about an hour of taxi time now, just waiting for the FSDO appointment on 11-20.

[Battson]

Like Gavin says - 25 RPM / turn of the governor stop screw is a fairly universal convention.
An hour at taxi? I hope they're not new cylinders? I can't recall which way you went with your engine.

[Battson]

The other more useful thing that came to mind - many prop manufacturers spec the static run-up RPM to be lower than redline, as much as 100 RPM below redline is acceptable / normal.

Often this isn't controlled by the governor, but limited by the fine pitch stops inside the hub. Obviously once the aircraft is moving, the same pitch on the prop will allow for greater RPM to be developed, until it reaches redline, at which point the governor starts working (provided it's tuned correctly). This is the situation we have with our prop. I will have to get the stops reset to achieve full RPM at static run-up, if we want maximum performance.