Ok guys, I'm having issues with my 98 big Bear 350 with a 95 motor. I went Creek riding a week ago and after an hour of riding, the big Bear just stopped and died. I got it started after a few minutes and drive it back home but it died again and would not start. When I got it home, I tore down the top end and found the piston scratched up really bad on both skirts, and buried the rig's inside the piston in one spot. Also leaving some aluminum from the piston embedded in the cylinder wall.... I rebuilt it and put a different jug on it along with a new piston and rings. Rode it for 15 minutes and it did the same thing as the first time. Just died and acted like it over heated.i thought the oil pump gear was broke so I took the cover off and it was not broke, I turned over the motor to assure it's pumping oil and it is. We are thinking it keeps over heating but we are not sure. could over heating be the reason why it keeps dying after a few Minutes? How can I fix this? Should I put the a different oil cooler on it?

 

I'd start with checking the air filter and the carburetor tuning. If it's running too lean that'll make it overheat.