Another Briggs12 series puzzle

[38racing]

Well I know what problem. Likely a popped intake seat. Intake valve isn't closing.

[38racing]

It was popped intake seat. Trying the peen back in trick. I think I tried to do valve clearance with tappet not forced down. Has a new valve now. This mower is 9 years old. A bit of carbon to clean off. What does the black at top of cylinder tell me. It's smooth, not like any build up
http://web.ncf.ca/da229/smallengine/Vic-cylinder.jpg

[bgsengine]

Looks like relatively normal carbonization for an L-Head - it eventually builds a ridge. Kohler K series were notorious for that carbon ridge cutting away at top of piston, exposing the compression ring,.. Also see signs of slight ridging in the cylinder bore, looks like it has probably had some dirt ingestion at some point in its life.

[38racing]

Got it running and returned it to him. Told him watch oil use. Apparently my changing air filter that fall for no start was first time. Maybe one oil change, all in 10 years of ownership.