i bought this 99 sport 400 2 stroke it was leaking antifreeze out of the head gasket, so i take it apart and think ,i'll throw a set of rings in it too. i get it apart an there's a chunk missing out of the piston (wow, and it was running so well). any way my question is how do you know when it is time for another bore job. the walls aren't scored up ,in fact you can still see the cross-hatch marks when they honed it. the piston says it's .050 over. with the rings off and the piston in the cylinder , i can get up to a .012 feeler guage in between the wall and piston. any help or advice ,please

 

A good piston to cylinder clearance is .002-.003

 

thank you