With the lower vent hoses going down and the top vent hoses going up into the air box it provides an air break to prevent sucking in water. Yes these tubes do equalize internal carb air pressure, but to do this air flows in and out. Engines are very dynamic things especially when you toss in the fact that they live inside a
very active environment of a dirt bike.
The bike has to be near upside down to leak fuel out of the top vent hoses. As was pointed out it will drain fuel out of the needle jet when this happens so there is not much more of a hazard.
https://slavensracing.com/shop/carbu...ilter-by-7602/
Uptite-Racing had them several years ago too. 111 W Dyer Rd Ste B,
Santa Ana, California 92707 Phone (714) 540-2920