Hi,

I guess you probably need new parts or new engine. New parts will be ball bearings and conrod. Leave the cylinder and piston as old.

If you want to check compression, it is simply. Take off the exhaust and header, take the engine out. The engine should have a flywheel on. Hold the engine by just the flywheel for up to 10 seconds. The engine should drop on either side and stay, if it doesn't stay and heatsink flips downwards, then compression does not exist. You will need new cylinder and piston also. Of course you will need to break in engine again.

Thx

Joaquim