I’ve heard a lot of good things about the R&D flex fuel screw so I decided to give it a try. After doing the research on my own because of the SEVERE lack of information on the manufacturers website, I found that its suppose to work on all Keihin flat cr carbs. Now this is where things get fuzzy.... the threads cut on, not one but TWO, screws so far have been completely different than the ones on my stock AND "T" handle needle. The screw simply will not thread into my carb. I honestly thought a few websites made a mistake by stating that it fits ALL FCR carbs, but even the track maint guy at the local shop is shocked that 2 have not fit so far! Just a couple incorrectly cut threads? I would like to think NOT, but the QC at R1 Dean has to be TERRIBLE considering the simple SPELLING mistake right on their packaging!!! (I mean how the hell do you miss that!!!!) 2008 YZ450F, Keihin Flat CR carb, 2 screws haven’t fit. The threads are not cut as fine as the stock screws. Has anyone managed to install this on a Yami in the same model years as mine??