**Verify the part fits before purchasing**Specs:Description: Mikuni HSR Jet Kit Closed Course Racing OnlyCarburetor repair kitsKits include all of the necessary components to repair a carburetor. ATV or motorcycle models with multiple carburetors include components to repair all carburetorsKit includes necessary all O-rings, gaskets, jets, needle, mixture screw, float bowl screws, float valve needle and seat. (Needle jet and other pressed in jets are not included in kit.) OEM jet sizes and slide needles are included in the kit. FCR MX style carb kits include extended fuel mixture screw.Harley kits contain jetting selection, extended fuel mixture screw, intake gaskets, and manifold gaskets.KTM and Husqvarna Kits do not include jets or slide needle standard jetting sizes are not provided by the Factory.NBR rubber material is used on all O-rings and rubber gaskets NBR has excellent resistance to the ethanol used in today’s fuels.Applications that use paper float bowl gaskets are upgraded to High Performance Interface Gasket material.Components included in the kits are based off of US models and discretion must be used when attempting to install the kit on a non US model.Off road use only. Compatible With/Replacement For:Harley HSR 42 0