rz003 replied to MN_Kevin's topic in TTRJust wanted to say thanks for this very informative post. I recently purchased a '04 TTR125 for my sons and have since added the powroll thrust chamber, re-jetted (17.5 pilot, 110 main), modded the air box (removed snorkel, screen, and drilled 3 1-1/4" holes)and am waiting for a high flow after market filter (bbr). I can't believe the difference these inexpensive and simple mods make. It took a little tinkering with the "air screw" to finally get the cycle to really pop. Throttle response is great now. Can't wait to see what the air filter does. This is a great site..thanks again to all contributers.