Normally the engine breather just vents to a catch tank somewhere. I think it is illegal for race bikes to vent to atmosphere so that's just a way of keeping things tidy and keeping any oil vapour from the rear tire.
Also if it results in a slight vacuum in the crankcase it will reduce oil leaks and reduce drag on the crank. As the bike wears and produces more piston blow-by it could affect the carburation adversely....
Nice gear shift and the swing arm looks pretty special, too. It would be interestesting to research the history of the bike and JRB. I'll ask around..
Has the bike got any oil lines running from crankcase to head? That's often a tell-tale of the 500 motors.
lloydy1 wrote:Here is some pics of the venting and gear change.G-Man wrote:Can you post some pics of that?