Small Engines (Lawn Mowers, etc.): briggs & stratton, briggs stratton, head gasket

Question
Hey Michael,
Spoke with you regarding my little 5 hp B&S awhile back. I told you about having to dismantle everything and remove the rust from camshaft, drive shaft, connecting rod, intake/exhaust, Replace the piston rings. Motor chanked on first pull and ran for about 45 minutes, but smoked some. Heard squealing, then it stopped running and wouldn't crank even with gas in the sparkplug hole.
You said compression problem. I checked the compression and it measures at 60 psi and I believe the compression should be 120 psi. Have not found the source of the decompression yet. New gaskets, piston rings in place and can hear sounds of suction when turning the flywheel/crankshaft. The only thing I can figure out is the intake/exhaust valves are not seating correctly. Doesn't seem to be any space between valve and cylinder valve holes, but valves don't fit completely flush in holes. Removed both valves and cleaned/buffed with plastic grinding wheel on drill. valves don't look bent. Any ideas as to where the decompression prob may be?
thanks,
Rick

Answer
Hi Rick,

The squealing sound was a bad sign and I would check the cylinder for scoring.  Maybe the rings didn't seat properly during break in.  If okay, move on to the valves.  The valve tops don't always seat flush but the surfaces must make full contact with the block's seats.  You can test them by coating the surfaces with blue marker and rotating in their seats.  Also check the valve stem clearance.  If not enough, they may not close completely.  Head gasket okay?

Let me know what you find.
Michael