I felt like this was important enough to everyone here to start new thread on this... After having trouble getting my pilot jet adjusted (not much response to turning it, hanging idle with any jet I tried, etc.) Woody wanted me to try taking the spring out of the deceleration valve on the left side of the carb. I also read a thread over on the 250 board that a guy named Larry had posted about this too (155 main jet or something.) Over there I was told the blocking off the small hole, where the little 1/8" o-ring is, would do the trick. So I first cut a small round piece of rubber about the thickness of the o-ring and just blocked off the hole and got rid of the o-ring, but still giving an airtight seal. That helped but not much. I then went back and pulled the spring (as Woody had wanted me to do) AND left the rubber plug, put the diaphram back in without the spring. WOW!! The sweet sound of popping on decel was back and so was the adjustability of the pilot screw, plus it slams back to idle quickly after a rev, no hanging at all (well some, until I tweeked it richer ) This valve is only on the WR carb and is there obviously to eliminate popping on decel (or to make jetting a f-ing nightmare.) James said he did not have a problem with idle & adjustments on his, so perhaps this is bike to bike. The fact remains that this is NOT on the YZ carb. And it's such an easy mod it's worth a try. I am going to take the diaphram completely out and make another rubber plug and just cut it all off completely. There is another small hole next to the diaphram that is still open as it is, not sure where this goes, but it's worth some more experiments. Woody...YOU ROCK! (Jetting) life is good!