[AgentX]

I'm not sure I'm following what you're saying there.

However, I converse with Tim regularly on the breather issues on another forum.

We both agree that the main breather, whether it's coming off the oil tank like the later models, or coming off the left crankcase like the earlier models, the breather hose routing should be the same.
...

Either way, it is important to route the breather tube up high right away, and then take the rest of the tube where you want to go with it....

Hi Tom-dredged this up researching.  What arrangement would you recommend for someone using a one-way valve instead of a duckbill?  Breather elbow to standpipe, valve at the high point, then back to the rear of the bike?  Or the valve further to the rear of the bike?

Thanks-

[ace.cafe]

Theory states that the closer the one-way valve is to the crankcase, the better it would function.
However, if oil gets burped thru the valve from being very close to the engine, and then there is a standpipe arrangement after it, then the oil can't get back to the engine.
So, I'd say to split the difference, and route the hose up high as a standpipe right behind the engine, and then put the one-way valve up there, and then lead the exit out the back of the bike or wherever you want to. Or you could put the one way valve at the catch can, like the factory does with the duckbill.

Sometimes a general compromise of things works out most conveniently. You don't always have to follow ideal theory in every application, because not all applications lend themselves to ideal theory.

[AgentX]

Thanks.  And I will definitely have to make a compromise, especially lacking a full rear fender on my bike.  Biggest issue is to avoid putting oil mist where it shouldn't be, really.  Appreciate the insight and will see what I can do.