172 Governor

[JWA]

The governor on my 841, 172CI is acting erratic. If I advance the throttle from idle to mid range 1000-1500 rpm the governor is constantly hunting. If I advance the throttle to the WOT position it runs fine and if I back down to mid range from WOT it runs fine with no hunting. I have gone through the linkage set up procedure in the manual twice and everything looks good. They do mention that erratic operation can be caused by a loose crankshaft hub, they specify 100ft.lbs. I'm going to tighten it some more today hope it helps. Anybody out there got any other suggestions? Engine was just built and governor operated fine before. Thanks Bill

 

[Bob]

Likely, it's a carburetor issue. Try richening the mixture a bit.

 

[DGinVT]

Carefully check the manual again(FO-20) para 146. They used two different governors. Due to the rebuild and the engine being tighter, you may have to readjust the linkage and check the bell crank adjusting spring.

 

[NoNewParts]

a governor hunting usually means it's working.
Big percentage of the time, it's a mixture condition like Bob said.
If the engine ignition and carb mixture is right, it will run happily at
any set rpm.
So, put it at the trouble spot and reach in and grab the governor rod and stop its movement. Engine should chug along with no issues.
If it starts to stumble or die without the gov there to save it, a mixture or spark problem exists.

also, like DG mentioned, 2 different governors were used on those engines. My memory is rusty, but I think an 841 should have had the later flyweight gov.
The issue comes when an early ball type governor is service replaced by the later flyweight style.
They take different governor compensating springs.

 

[Bigdano]

The governor on my 841, 172CI is acting erratic. If I advance the throttle from idle to mid range 1000-1500 rpm the governor is constantly hunting. If I advance the throttle to the WOT position it runs fine and if I back down to mid range from WOT it runs fine with no hunting. I have gone through the linkage set up procedure in the manual twice and everything looks good. They do mention that erratic operation can be caused by a loose crankshaft hub, they specify 100ft.lbs. I'm going to tighten it some more today hope it helps. Anybody out there got any other suggestions? Engine was just built and governor operated fine before. Thanks Bill

Did you ever fix this? Mine doing the same thing…

 

[JWA]

Did you ever fix this? Mine doing the same thing…

Yes, I replaced the governor.

 

[WayneIA]

From experience, make sure the governor spring in not rubbing against the side of the block. Like to hook the spring to the governor rod outside-in

 

[Bigdano]

From experience, make sure the governor spring in not rubbing against the side of the block. Like to hook the spring to the governor rod outside-in

Thank u sir good tip