gtx 2000 shut off when running

[wacos]

i got a gtx 2000 951 engine. jetski run's fine after we get the jetski run for a little while at 50 mph jetski shut off.when try to cranck sound wear after we left the beach we get the spark plugs out. found one of the spark plugs the electro is bent like someting hit it. remove cyl. head found piston is crack all the way around at the top and one of the ring is freezz. do you guys think the jetski have some problem with gas or if is another think. let me know please thanks

 

[seadooya]

need to pull apart motor, and find out, bud.

 

[wacos]

i just removed the head of that cyl. and cyl is ok rod have a little be of play. but the think is what cause that problem