- Jan 13, 2008
My '74 Commando has always had an oil leak coming from the front of the engine around the head gasket area. While I was doing a recent top end job on it I read about the likely cause for the leak in the Norton Tech Digest. It seems that the two 5/16 studs that screw into the front of the cylinder are the cause. The threaded holes for the studs are drilled in such a way that they protrude into the push rod tunnel cavety. This allows oil to work its way up the stud threads and eventually out to the atmosphere. I did as the Digest recommended and reinstalled the studs with gasket sealer on the threads. Problem solved. I highly recommend that anyone with a Commando obtain this Tech Digest from the INOA, lots of useful tips. Cheers!