I put a 38pj in my 2000 WR400, along with a 155 main and the EKP on #3 and the bike would barely run. Is there a huge difference in the carbs from the 00 400 to the 01 426, which is what most ride that have done this jetting? I thought the carbs were identical and the motor is just slightly bored larger. I wouldn't think this would make such a difference. It's running decent now with the 155 main and the #3 EKP and the stock 42pj back in and 3 1/2 turns out. I haven't been able to order the 65 paj or the 160 maj yet. Should things change with these two jets to the 38pj? Also, you guys suggest replacing the paj with a pas that is adjustable. The Sudco rep told me to look into the Zip-Ty one because it's nicer than their's (gotta love those guys, sending you in the right direction at their expense). I think he misunderstood me, as this is the air screw on the bottom of the carb, not the jet inside the manifold. Where can I get this adjustable pilot air screw to replace the paj. Does anyone have PN's for the paj and maj, so I can order them? Any input would be appreciated, as I apparently need help beyond the 01 426 setup for my 00 400 setup.