Originally Posted by Dasmailca
When I removed the head I discovered a not so small groove scored in the cylinder wall as well as small pits in the head. Even a small piece of metal embedded there.
It seems that something in the bottom end has disintegrated. Is there any thing I can do ? Are there better quality parts to rebuild with ? Is there a better quality engine to start with ? Maybe 4 stroke would be a better choice ?
The damage is from your needle bearing coming apart.
Probably the upper one on the piston.
What motors and where have you been buying them?