This jet kit is specifically for a 250/300 2-stroke with a Keihin PWK 38mm AG Short Body Carburetor. This is a jet kit only; it does NOT include a carburetor. It is not designed to tune bikes with the stock carburetor on those 2 stroke models. This kit includes main jets, a pilot jet, custom multi-taper needles and needle clip designed to improve throttle response throughout the range. **Note: For these 2-stroke models with stock carburetor see specific brand jet kits.