B&S engine governor problem

Was the linkage disconnected when you took off the carb? If yes then look for wear marks on the adjustment holes, is everything in the right place? Also look for missing or broken tension springs. There is a possiability that the clamping portion of the control arm changed its position when you took off the carb. Short of gaining a manual I can say nothing else, I am not familiar with your paticular engine. One possiability is to set the arm clamp in the middle of the travel distance and try it, make adjustments from there. Best is to wait for a correct answer if you have time.

 

How dirty is the cover? I just took the cover off my mother laws mower a few weeks ago.The little flap that pushes back and forth under the cover was not able to move properly because of dirt cling to it.This part opens/closes the Governor.Might take a look.

You also have the same engine that i have on my rider.Also a few weeks ago i washed it off Good! got the coils/plug wires wet.It ran fine until i put it under a load then you could tell something was wrong.I cant recall it smoking,but it did stumble and miss fairly bad.I let it dry out over, night next day it was fine.Could your problem be do to one cylinder not fireing?

 

What year model is the engine? I would almost venture to say your problem is in the magneto or electrical charging system.

 

The reason I postulated the magneto or the charging system is because that is what it sounds like to me. First things first though, the wire from the magneto where it emerges on the engine to the outside should be checked for brittleness, or cracks. Chances are that you got your engine hot more than once and the excessive heat will cause the wiring to turn brittle and crack in most cases.

You may also want to remove the safety cover from the top of your engine (or the side) and lightly sand the edges of the magneto to remove any rust that may be covering the magnet area. Rust builds up because of outside moisture in the air (high humidity) and leaving the lawnmower out in the rain and other elements.

Through cracks in the wiring, you will lose power due to "arc-ing" of the spark or fire. You can find this by inspecting any area where the wires are close to heat sources such as the exhaust area, or of the engine block itself.

According to what I read, you thought it was a governor problem. Well, you are mostly right because the real problem is the way the fuel burns.

An engine needs three things to run. Fuel, Air and Fire.

Apparently you went completely through the fuel system and you have a clean air filter, so it has to be a "Fire" problem.

From my own experience, I have had a similar problem like yours where my motor worked fine at an idle, but when placed under load, it slogged through short grass and died in the tall stuff. A friend told me about the wiring aspect and I checked that. My wiring was okay, but when I looked at the magneto, it was covered with rust. After I sanded off the sides of the magneto with store bought sand paper, medium grit, it works like new.

Basically, when you go completely through your fuel and fuel delivery system and find nothing wrong, there IS nothing wrong with your fuel system. It has to be an Air problem, which does not seem to be the case here, so that leaves the "Fire" aspect. I hope this helps you.