When your motor sputters through the whoops or bogs when landing from a jump and G-outs, it is often caused by fuel being vapor-locked in the standard downward carburetor vent tubes. This vapor-lock action is similar to putting your Finger over a drinking straw to keep the liquid trapped inside. By venting both hoses upward, the PC system allows fuel to drain through the downward vent tubes without hesitation and ensures continual air flow into the carburetor. To be sure that the upward tubes don't draw or get clogged with dirt, the foam filter-equipped vent box filters the air that the system breathes. Another vital function of the vent box is keeping water out of the upward vent tubes when you wash your vehicle. With the PC system, off-road riders don't experience the bogging common in stream crossings when the drain tubes are submerged in water and while being bounced around on rough terrain. Although the standard venting is improved on some of the newer motocrossers, problems still persist over obstacles which result in continuous bouncing, such as whoops. The new PC system includes additional T-vents to improve venting on these motorcycles, and results in fewer vent lines hanging from the bottom of the motorcycle.
