Why is oil leaking from muffler on B&S 16hp engine?

Briggs had a number of problems with inlet valve guides and valve stem seals leaking, i have had to change a number of cylinder heads on the OHV engines, this was the only cure, later engine had an additional head bolt due to head warpage.

Husqvarna man
March 2010

I never had the engine tilted to a side. It's always flat, even when I'm working on it. I let the mower run about 5 minutes and it continues smoking. At first I was hoping residual oil from the gasket I changed may be the culprit, but it is still smoking so I know that's not the case. My guess is there has to be oil getting inside the muffler because I don't see any leaks anywhere else. I don't know how oil could get in the muffler though.

Matt Davis
March 2010

Not sure if it helps but often when you tilt the smaller mowers to one side or the other such as when cleaning the grass away underneath , this can cause oil to move about and often enters the air filter system as well. Have you have the mover tilted over to any extreme while working underneath recently or at the end of last season ? Just a possibility that its leaked into the muffler ifyou are saying its fresh then possibly done when the oil was changed. It may just burn off . Try checking the level then running it for a while to see if it burns off (about 4-5mis max then let it cool and check the oil level again and if its not smoking nd the level is still same as before you ran it then that might have been the cause.
regards
Gaz

Gaz
March 2010