If you are having issues of blow-by oil in your air filter, here is a way to end it. The rocker support plate has two small holes for oil return under breather plate. Remove support plate and drill out holes to 1/8" and put back together. A instructor at MMI told me this, and did it to a friends bike who had bad blow-by and it took care of it.
I'll post pics as soon as I can figure out how.
Eric

 

This is taken from the Doherty Mystfree breather system. They advise to use a #43 drill bit (close to 1/8) and drill out the rocker supports. I do it to all the bikes I go into. HERE's a pic

 

Thanks both you guys for the post..

 

These holes are not only drainbacks but the source of air exiting the engine while breathing. A slight increase in dia will give benifit, but go too big the first few revolutions at startup will be quite aggressive to the umbrella valves. Once running the outflow is low, but increases with high rpm loads. The .089 is a good compromise for both operations in my view.
Ron

 

Interesting. Would head removal be necessary to perform this?