Motorcycle Repair: compression, piston rings, reed valves

Question
The cylinder was bored out new piston and ring but has no compression I thaught head gasket but not sure piston and ring seem fine of of bike sorry it is a 2000 rm 80 email is wilson1340@fairpoint.net was wondering if piston could be to small I am third person too look at and didnt order parts thank you John

Answer
Hi John,

Measure the cylinder and piston and then determine piston to wall clearance. If PTW clearance is not within service limits, determine which part is out of specs and repair accordingly.

Check piston rings for proper instalation.

Check reed valves for defects.

Check crank seals for defects.

Perform a leak-down test to help locate the source of the leak.

Respectfully,
Mark Shively