Do you mean to tell me that there are 3 different diaphrams for the accelerator pump? I own a 2002 YZ426F, I installed the P-38 Lighting cover from Factory R&D, it seemed to help allot at first, but I feel like the sputter is coming back when I snap the throttle real quick! I would love to eliminate this sputter, I'm running a 165 main and a 45 pilot with a stock needle at stock position, pilot turned out 3/8, any tips? Buy the way, I just installed a Protaper Twister throttle tube with the needle bearing in it, what an amazing mod! I have so much throttle control now, worth the $80.00 big time!