[kerin sargent]

hi got a gp1200r 2000 model and i have a big chunk out of one of my pistons and the rings are showing. really suck on what could have caused this to happen if you guys have any ideas please let me know cause i am relly stuck thanks.. also got it all stripped and i was just wondering how i can tell if the oil pump is working proerly as i can not turn over the engine except by hand:dunno: :dunno: :dunno:

 

[craig connolly]

Welcome to YAMAHA chief! I am an old YAMAHA service mgr and Technician, these skis are horrible for this problem!! 99% of all piston failure is due to lack of lubrication, you cant check the oil pressure with ya hands! you getting ready to spend alot of money on fixing this ski! YAMAHAs arent cheap to work on, you need to fix the engine then rebuild your carbs, do not skip the carbs!!! then you would be wise to mix your oil!!