Producing power without compromiseThe motocross world knows PWK. Keihin PWK carburetors are the dominant carbs on the factory motocross machines. Because of their great performance they come stock on a lot of the leading brand bikes. PWK FeaturesChromed semi-flat (D) throttle valve for excellent response and more flow at high RPM. Throttle bores sized to give maximum power. Easy jetting with jetting parts available. Quad Vents: eliminates post jump bogging from fuel plugged vent passages PWK Air Strikers : directs air to main nozzle for improved signal and throttle response.