Hi,
I can not see how these symptoms could be a piston or bore issue. More likely fuel or crankcase compression. I have had a misaligned flywheel on a PT. The blade nut was not done up tight enough. Ruined the flywheel.
Still needs the motor taken off the base though, probably easier to put another one on.
If you do have to take trhe motor off the base, please take a picture of that factory pulley for me. I would love to see what a real one looks like.
All the best
Jeff
