We have found some "easy" horsepower in these slide springs, specifically designed for three altitude ranges and inlets (stock or modified air box or carb filters) for the Yamaha RX-1 snowmobile. Improved throttle response and up to a 1000 RPM increase results from the use of these springs. A set of four springs come in a convenient carrying tube .

RX-1 APPLICATION TABLE

For Vector applications, use the Green springs for 0-4000 feet, Yellow for 4000-8000 feet, Red for 8000-12000 feet regardless of inlet (air box or filter application).