Already blew/burnt a chunk out of the head gasket on the superhonda 850. Not sure if bad gasket or too much power. Maybe the head wasn't quite flat....gasket had steel fire rings. Noticed a snapping sound and smoke blowing out the side of #1. Found this gap: so hopefully I can pull the mill, check the head, fit new gasket, reassemble and put back in the frame in one day with the help of some strapping young lads...