The most effective way to add performance to an FCR carburetor. Integrated Hot Start Assist eliminates problem 4-stroke hot start procedure. Tunable leak jet maximizes volume of fuel and duration of fuel spray for all conditions. 25% more fuel capacity. High-volume vertical check valve located in the QS3 for precise, consistent fuel metering. Patented design stops bogging and improves throttle response. Improved low-end performance. Investment cast and finished to precise tolerances. Simple bolt-on installation. For all FCR Carb-equipped MX, off- road and ATV models