Not sure whats going on with my Briggs 5.5 hp vertical engine... Governor failure?

[arbowman]

Hello. This is my first post. I have a 5.5 hp vertical Briggs push mower that runs ok but it won't rev to full rpm and the engine just sounds like it is missing. It hasn't ran right since I've had it. I bought it used at an auction. The carb is clean. There is good spark. There is no rust on the flywheel or coil. So I started messing with the governor arm and the springs and no matter what I tried I could not get the engine to rev and run well and sound right.

Then suddenly, the engine started to rev and run strong when I was messing with the governor arm and the throttle linkage. I thought it had magically fixed itself. But then 20 seconds later it went back to running poorly and not revving. Then after running poorly again for awhile it suddenly started to rev and sound good again but stopped running good after 20 seconds again. No matter what I did after that I couldn't get it to stay running right. SO....

Is it possible the governor gear and mechanism inside the crankcase has something wrong with it that won't allow the engine to rev?

I tried everything I could do externally. This would make sense because the engine doesn't want to rev like there is something causing the governor to restrict the engine at all rpms but then the engine runs perfect when the governor decides to work correctly again.

Has anyone ever had an issue like this?

Is this issue something completely unrelated?

Thanks in advance!

 

[BlazNT]

First it is a used engine do not assume everything is connected correctly. Change the hole the governor rod is in and see if that fixes it. Engine model number would help a lot.

 

[arbowman]

Thanks for the response!

The engine model # is 123K02-0357-E1.

There are no extra holes to change the position of the governor arm. I did everything possible with the spring location and adjusting the position of the governor arm on the shaft. Nothing I did would get the engine to run correctly like it did on 2 occasions for roughly 20 secs. I have no idea what I did to cause the engine to run correctly. Its like the engine magically fixed itself but then went back to running poorly.

It almost has to be the governor mechanism inside the crankcase causing this issue. The engine would not have run awesome like it did for 20 secs if anything else was wrong with the engine.

I found the governor and the crankcase gasket for this engine online for around $20 shipped. I think I am going to swap the governor out with a new one unless somebody says that there is absolutely no way my problem is because of the governor.

 

[BlazNT]

Let us know what happens after you change it.