I have a Sportsman 335 and noticed engine oil leaking from the right hand side of the ATV close to the bottom of the recoil housing. There is a hole that is 1/8” in diameter and when the engine is running you can see oil pushed out through this hole. It is in the location where a water pump would be if the ATV had one. There is a oil seal that came out of place. How big of a job is it to replace the seal. My bike is air cooled. Any help would be appreciated.