I had this problem also. Mine seemed to be puking out the rear exhaust push rod tube as well as the breather. I change the O ring three times before I gfinally got it to stop. It was still blowing out the breather but not as much. I realigned the oil pump when I put the cams in.
The problem with the push rid tube turned out to be mine. I topped off my oil before starting a long ride and overfilled.
The problem with the push rid tube turned out to be mine. I topped off my oil before starting a long ride and overfilled.
