Originally posted by ricky1: I ordered the adjustible PAJ. I don't understand why you use a smaller PAJ when you go to smaller pilot jets? I don’t either, but it does work better. Apparently the main – main air jet and pilot – pilot air jet sort of go together, go larger on one and you may need to go larger on the other. IF that is the case then I’m at a loss as to why the WR comes with a 75 and the YZ a 100 since they both have a 42 pilot, but the WR is obviously getting less air in stock form through the carb. BTW you may also try running without your main air jet altogether. 200 is the largest size avail., and all the thumpers come with that size (DRZ, WR, YZ etc.). On a tip from a road race tuner somebody on the WR side tried going without it and it worked well for them and others. Removing it effectively results in a passage that is in the .210 to .220 range. My bike seems to hit the rev limiter slightly better without it. The MAJ is right next to the PAJ.