Governor question

[rcchristensenjr]

Unplug one spark plug wire at a time so engine is running on 1 cylinder. If you have a dead cylinder you probably have a valve problem. Most likely exhaust valve.

 

[StarTech]

May not be a spark issue very carefully feel the exhaust pipe going into the muffler if one is not firing it will be cool but be careful not to burn yourself.

Yea touch an exhaust pipe that might be 400F+ degrees. Can you say BBQ human? Basically HLW49 are you nuts? Third degree burns are not fun at all.

Just tested a Briggs here that I having a problem with and one side is running at 700+ degrees F and the other only at 125F. I finally narrow its problem so it should fixed next week. Just had other things to do today. Like 4 Stihl trimmers.

One side is running way lean the other so lean it not even firing.

I have put a spark tester on each cylinder while running and when it's under load, both show a steady spark.

And spark tester will not show a shorted plug.

I just wondering how old the engine is as could be a worn out cylinder which a cylinder balance might show or a leak down test.

 

[hlw49]

Since we have no exact model no. could not look up exact engine. I would assume it is a single bore carb. If it were a two bore carb. I would say one side of the carb. may not functioning as it should. This could be the problem on the Briggs Star Tech is working on.

 

[arch252]

Responding to several suggestions: it has a brand new 550cca battery. I used a laser temp gauge, both exhaust pipes got up over 700 degrees. The engine model # as stated in the original post is a FD501V, single bore carb. Update: I have two LX279's so I did an engine swap today. The good engine worked fine on te mower with the problems, so that rules out the deck, belts, pulleys, battery, etc. The problem is isolated to the engine.

 

[arch252]

Among the many things I had replaced on this mower was the Ignitor/CDI control module. One cylinder was not firing and the diagnoses led to the CDI. I purchased an aftermarket CDI but it corrected the issue and both cylinders were firing correctly. Could the CDI cause the drop.in RPM's under load?

 

[bertsmobile1]

Yes

 

[arch252]

Update: I cracked the case to check the governor. Governor appeared fine. Spent $40 on sump and crankshaft gaskets and put it back together and it's running fine, not dropping rpm's. The only thing I can guess is that something in the governor linkage was in a bind.

Now for the the bad news. This engine has been fighting me all the way. Fix one issue and another occurs.

Gas is leaking out of the overflow on top of the carb when it is running and under load. It runs fine, just excessive fuel. I'm at a loss! Any suggestions?

 

[arch252]

It's a new carb and it wasn't doing this before I opened the engine.