Genuine Keihin jets provide the best replacement or calibration solution for your Keihin carburetors.  Do not use an imitation, nothing substitutes for OEM quality and Keihin jetting is guaranteed to be the exact size indicated because of high manufacturing tolerances.  This Keihin fuel screw kit replaces the worn out fuel screw set on your FCR-MX carburetor.  Includes the screw, spring, washer, and o-ring.

Additionally this screw kit can also be used to lengthen the fuel screw on the original FCR carburetors, it is 50mm long.  The fuel screw is typically hard to get to and the10mm of extra length makes it a little easier to adjust on these carburetors.