I have a 04kx250. Live in Alaska, third ride on bike yesterday. Ride at sea level, use 50/50 race gas/super unleaded, Amsoil Synthetic 40:1, stock jetting. Been fouling plugs, but a new plug would get a ride out of it. Yesterday the wierdest thing was happening. It was about 50F (warmest ride yet) The bike would start fine , idle fine , and put around fine (up to almost 1/2 throttle) When I went out on the road to clean it out, as I would give it full throttle, it would bog out and foul. I could blip the throttle (about 1/4 throttle) and get it to clean out, and ride some more, but any attempt to go WOT had the same result "bbbbbbbbrrrrrrrrrrrrrrrrrrrrr" I moved the clip one (cause I didn't have a different main jets) and then I could get just a little further into the throttle before it bogged out. I could ride around (and did for an hour). It sounds like to me that the main jet is too rich and I need a smaller main. Stock is a 165, I have a 162 from last years bike. I ran stock jetting on my 03 and never had a problem. I was concerned that the electronic powerjet could be out of time. Does it sound like main jet or power jet problems?? I also have a different needle, it came with the Pro Circuit pipe on my 03. Contemplating putting the Pro Circuit jetting pack in. Thoughts, suggestions?