Did this on my blue bike, and on my dads red. First thing I did was take the breather and split it into two lines, then I took one of the lines and put a 1 way valve on the line to allow flow into the crank case, I then ran this line up and into my airbox between filter and carb, so I get filtered air into my crankcase. Then I put a 1 way valve on the other hose that allows flow out of the crank case and let this line hang down. Works like a dream. For the valves I just used some small hose valves that my dad just literally had lying around, you can probably find them pretty easy. This setup has a few benefits, it eliminates the oil that you get in the airbox usually if you reroute lines to box, and it of course ends dirt and water getting into crankcase and carbs, unless you managed to get water in you're airbox.