My Hyper sprung a leak out of the vertical cylinder side cam cover (left). For some reason it is becoming common on the 1100DS engines. The o-ring that seals it is the same as the horizontal cylinder, but for some reason the horizontal cylinder doesn't leak. Ducati has replaced o-ring #886.4.060.1A with 886.4.060.2A. I figured I would supply this number since it isn't in the parts list yet. Supposedly it is back ordered from the dealerships but I found it at commonwealth cycles. http://www.store.commoto.com/parts-ordering.php.