Hey Bogspores, I'm hoping you are still active on here. I have encountered seemingly the same issues with my 06 KFX 400 and can't figure out what to fix. The bike almost always sputters and loses power instantaneously only when in 3rd gear and riding up an incline, or terrain that adds a "load".... Running out of options, and hoping to fix the bike as opposed to walking away from it... Thanks

 

Just bought same qaud guy said it set for 3 years not ran or driven so got it home played around with it replaced carb ,plug , then took it to local track and off the get hit the throttle and it begins bogging out and revs out in first super quick went to second power drags all the way 3rd and its not stock I have a athena big bore in it but carb is stock jetting is next to see if that fixes the issue and change the oil since I don't know when is was last done and just a side note does anyone know where to get a aftermarket ignition box for the key toreplace the broken plastic ones to aluminum I seen a kid on utube show that he bought one to replace same issue