oil out of breather 8 hp tecumseh

I picked up the motor for a go cart application. it spews oil out the breather. could it be as simple as replacing the breather(bad reed valve?) or ,with my luck could it be worn out rings. what if any are other possibilities? if I can get this problem licked would be great. I don't want to go back to the 3.5 hp after running the 8 hp. are there any other areas of problems I should be looking out for? thanks