now go easy on me- this is my 1st off road machine- I have had it a year and this has been a major learning experience- here is the issue I have done all of the free mods on my 04WR450- I bought it new off the floor last year- I have not replaced the pipe-I only took out the baffle-Yep she is loud- but I only ride on private property. My riding partner bought an 06 WR450, did the mods, put a GYT-R pipe and jetted My 04 runs great!! It starts every time, hot or cold, does not stumble, does not backfire, and when we switch bikes, the only difference I feel is the way the power is delivered, his does seem to come a little quicker. When I look at my plug, it does not look burnt or fouled. I say I should leave well enough alone- I have some folks I ride with say jet. Who is right here? Quite frankly I am a chicken when it comes to the jetting game- If I F-it up out comes the carb again,and again. I do plan on getting the mixture screw and putting that in- I have been told that is more important than jetting- is that correct also?