I checked the spark plug....it's tan, and the center electrode is crisp, with clean edges all around.....

 

O.k.....I took it out again today......I think I've got it figured out.......

My engine simply has a "boggy" spot between what "feels" like 4000 to 5000 RPM.....If I goose the throttle at the first sign of this "bog" it'll rev right past it, and run like a raped ape!.....

It's consistant in every gear at about the same RPM......I'm learning to "romp" the throttle whenever it happens......

I also found the high speed limiter today, so I know what it feels like.......

Bottom Line: My engine just likes to putter and stutter when transitioning from low to high RPM

Does anyone else with a KFX400 have this problem?.....

(I also felt froggy today, and attempted some wheelies.......first good one....it dumped me right on my a$$.....scraped the grab bar up real good.....I'm an idiot!)