I have a 01 TTR 250 and I replaced the stock air box with a Vortex box, My question is, can I do away with the breather assy., cap off the breather hose at the air box,take the drain tube from the bottom of the breather assy. and attach it to the breather hose coming off the head. Or is all this hose and breather assy crap necessary?
I haven't looked closely at the TTR250 but in general terms the crankcase vent doesn't need to be routed to the airbox. In most cases it's a performance detriment to do so. Routing the breather hose to a high spot on the frame and attaching a small K&N or UNI breather filter to the end of the hose is a good clean approach that will keep hot oily air from entering your airbox.