Hey guys just tore into a 2001 426 yzf yamaha tonight and I thought that the piston was seized in the jug... not the case unfortunately.
Took the jug off and the crankshaft will spin a-okay but the piston is locked on to it tighter than can be... no play what so ever. There is a heat mark on the right side of the crankshaft next to the piston, but I have seen other full, complete, and functioning crankshafts with the exact same spot in the same location. That almost leads me to believing that the heat mark could be from assembly..?
Anyone hear of any similar stories or experience this themselves and know what caused the failure?