I dont know if you saw my post in the LT 80 thread. I test rode a 2005 KFX80 with a FMF and that thing was way too peppy!! just about pulling wheelies when it hit on power band. Cant imagine how fast itd been with a rider that weighs 200 pound less. plus when i tried putting around it kept fouling out the plug.
I think I maybe found a 50... he will get an 80 in a year or two