Top end been done wrong?
My son’s bike is 6 hours into a full top and bottom end rebuild, on Sunday he was on the track and he heard a loud crackle and the bike but out but never locked up. Took out the spark plug and noticed the bottom electrode had snapped off hence the bike cutting out. Tried and new spark plug but wouldn’t start.
Upon doing and compression test it didn’t lift the needle a slight bit I thought the piston/rings may be damaged from the small piece of metal that broke off the plug. I’ve noticed this ring on top of the piston clearly where it’s been hitting the head insert…am I to assume the mechanic has NOT set the squish correctly hence the piston eventually wearing and hitting the spark plug and snapping it which has the cause damage to the side of the piston and snapped the ring!
I’ve asked the mechanic and all I got back from him was “no idea” wasn’t that unfriendly when he wanted the custom and £800 to carry out the work.