The FMS02 fits the original Keihin FCR carbs. (Originally, this was a road race carb adopted for motocross usage.) This part fits the YZ/WR 400Fs, the 02 and older KTM 520 and 400 'RFS' bikes, and the DRZ Suzukis. Please note that some of the DR-Zs - streetlegal - do not have the Keihin pumper carb - at least what we've seen in California (for our stringent - read: ridiculous - emissions laws).

This Zip-Ty Fuel Screw does not require any carb modifications, like filing or grinding, as other makers' screws do.

If the Fuel Mixture Screw collar is above the main jet access bolt, it takes an FMS01. If the collar is level with the main jet access bolt, then your carb takes an FMS02.