CBR 600 splutters at 6500 rpm

[Judd]

Hi, have had my 98 cbr600F for some time now with no probs. i know something happens at 7000 rpm that boosts the power, but not sure what it is mechanically.
Anyway, the past week when i reach just under 7k i can feel a slight splutter (but cant hear anything). As soon as the revs hit 7k all is ok.
Any ideas ?

[Heckthusula]

That sounds like a flat-spot. They're a bugger to fix as it could be any number of things, but a good place to start - if you have the cash of course! - is re-shimming, new airfilter and carb-balancing.

Incidentally, there's no actual mechanism for "Boosting" the power, it's simply that the engine reaches a point where it's creating it's maximum power, the "Sweet spot" if you will. Torque x Speed = Power, until friction takes over.

[the grim reaper]

I'd get your valve clearances done, 99% chance that it's that causing a bigger than normal flat spot that then makes the bike feel more powerful at 7k.

Cheers

Grim
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[Judd]

thanks guys, will try all of above