A friend of mine has a Polaris Predator and while riding this weekend, he heard a loud pop. Oil started coming out of the engine and he noticed a hold in the right side of the engine case. I do not know much about engines but was wondering if anyone could tell me what may have caused this or if they have had a similar problem.

I tried to get some decent pictures of the hole. There is actually a metal object still poking through but it is hard to see in the photos

 

Looks like a bolt or something broke on the clutch. The best thing to do is take it apart and see what is broke. The hole can be welded shut.