my friend has a 98 grizzly and we went riding yesterday at the sand pit. he was attempting to go up a steep hill when he got stuck half way up. he let it roll back but accidently used the rear brakes and it flipped over backwards.no one was hurt but when we flipped it back over something happened to the motor cause now it will not turn over. his grizzly was upside down for only a few seconds. we pulled the spark plug and tried to crank it over but no luck.we tried the recoil but the motor will not budge. we tried to pull start it with another 4wheeler but no luck.so we ended up putting it in neutral and pulling it home.what could be wrong with it?

 

anyone got any ideas