I installed this updated kit on my 05 450x. I had the off idle bog/hesitation with the bike which was annoying and made the bike difficult to ride. I installed this kit along with a JD jet kit and leak jet kit and Merge racing ap spring and CRF Only fuel screw. The bog is gone, replaced with instant and smooth throttle response. Makes the bike more fun and easier to ride, especially in the low speed stuf
Bought a 2004 crf250x that wouldn't idle and ran horrible, put this kit in it along with a jd jet kit and jd fuel air screw, bike runs great now!!
CRF`s Only Response: We have updated the description to include this information. As Brian mentioned the updated accelerator pump cover is optional. The main benefit is the updated diaphragm and as reviewed it works very well. -------------------------------------- If you plan on putting this on a 07 or earlier , you need to remove the check valve from the float bowl as this new cover has one built in it. I kept the old pump cover but used the 08 diaphragm and it worked great .Would have been nice to have that info before installed.I put a QS2 with the 08 diaphram and a 40 leak jet and man this bike rips when you snap the throttle.