oil breather

I have a 1971 750 Commando. About 1.5 years ago the engine seized and destroyed the case. Luckily I found a mechanic at Fair Spares New England who specializes in Nortons. He rebuilt the engine using a Combat case. The problem is, that case has a rather robust vent behind the cylinders towards...

I have a very late 1972 750 Commando Fastback. Over the last few years it has started pushing out oil (it seems every where). It has be suggested it might be an oil breather problem pressurizing the crank case. It has the oil breather coming off the back of the crank case and it is clear. My...