Hi There, I have a 2000 XR650R that I purchased used. It is uncorked and has a B53F needle in it, which I suspect is giving it a funny throttle response. I tried to order a B53E needle at my local dealer and the parts person said he couldn't do anything with that number. I said it was from an HRC kit but that didn't help him. He spent about 10 minutes going through Mikuni and Keihin catalogs to look for the needle but couldn't find it. Does anyone here have the Honda part # for this needle? thanks, Mike.