carb was checked, was not leaned out.
porting was not crazy, fairly standard for xpw cylinder, no popup.
the only thing I can gather is the intake boot / carb screws were slightly loose, possibly contributing to an air leak there.
other than the transfer the bearings seem to be fine, and the saw did vac test 100%.
I ran a gasket, the cylinder bolts were tight.
the gas was blue .... and the gas in the carb was blue. carb flows fuel through it.....
and in case anyone wants to know a piston for a 51.4mm cylinder is $80 shipped.
I did the teardown in front of the customer...carefully. he has his $ back ...