geelak900
Active member
Possible that piston was in backwards? The arrow on top which typically points to exhaust side is critical. Reason for this is so it positions the piston so the ring end gaps land on a solid portion of the cylinder wall and do not pass over any of the ports. If the piston is turned 180 degrees one or both of the ring end gaps pass over a port in the cylinder wall and will catch the edge of the port and either break the ring off or break a chunk of the piston out above the ring land.
