How to stop oil flow from crankcase breather house to air filter port

675 Series. Engine build date 6/10. Runs a Huskee log splitter. Oil comes out onto the air filter from the crankcase breather hose when engine is running. Oil reservoir has NOT been over-filled. What's the fix? Also, when i enter the model # into the B/S website to obtain a manual, it says 'no matches found'. I have a serial # as well. Any clues on how to get a manual online? Thanks.