A variation on the reroute is to mount the T fitting directly above the cam cover port, and then run the original stock breather down the front just as it is. Then run the new section back and into the airbox with an added filter as in the pictures here. That splits the breather exhaust into two directions, and the strength of any vacuum pulse is cut in half as well. If and when the lower tube would try to lift anything heavy, air will rush in through the top section instead, being the path of less resistance. This question probably stems from my lack of understanding of why the hose is there in the first place (don't remember there being one on my 05 crf). Is there a need to have a downward / gravity component to the breather assembly? Does oil ever come out and need to go down hill. I had wondered if there was ever oil in the hose could sand wick its way up the oiled hose? If there is a good reason to leave a hose down plus take one back to the air box with a filter on it I will go that way. Looking at the new wr's they go into the air boot which is fine as a factory item and no need for another filter but I wouldn't dare rig something like this (but still no downward component). Perhaps the 08 wr boot with its coupler would fit on the yz's. That would be the most factory setup. Anyone done this? I even had friends reroute their breathers into the air box before this happened to mine but I thought without a filter on it that's almost worse as the air box fills with sand and dirt over time and then gravity would be working against you as garbage bounced it's way down the hose into your engine. It only made sense for water. Long question short why the need for,or the possible benefit of the downward hose?