Small Engines (Lawn Mowers, etc.): Briggs & Straton Valve Seat, briggs straton, craftsman lawn tractor

Question
Eric,
I have a Craftsman lawn tractor with an 18 hp Briggs #422437. It has steel valve seats and and an aluminum block. One of the intake valve seats keeps popping out of its groove in the block so I lose compression. I've snapped it back into its groove but the grove must be warped or worn so the valve seat isn't secure enough to stay when the engine is running. Is there any way to repair the valve seat or do I have to buy a short block? Thanks.


Answer
The manual tells you to "peen" around the seat.  Basically you make sure the seat is in place and then use a center punch and smash the aluminum around the seat to hold it in place.

This will work for a while but I've seats pop out after peening.  JB Weld may also work...I've heard of people doing this.

Is the engine running too lean and over heating?  Usually the exhaust seat come out before the intake?
How old is the engine?
Let me know.
Eric