Have noticed a very short power loss then suging when i approach 9000 rpm's. Only mod on bike is Yoshimura slip-ons with baffles. Changed plugs using ngk iradium plugs bought at Honda dealer, which did not change surging. The old plugs were clean and a light brown color. It has lost some top end speed as well. Using a accurate sigma bicycle computer i was able to run bike to 138.6 mph on a long straight stretch of road last spring with stock silencers. Tried same road today with no wind and mild temps and bike struggled to hit 130 mph. There is no power loss at any other rpm's It is a 1999 with 5500 miles on it. My assumption is motor running lean on high end. Thank you.

 

you drive fast in nebraska! at least you have lotsa wide open road.

To clarify - you noticed the problems with the slipons, not with stock cans?
Not many miles - has it sat long periods of times (carbs and jets dirty?)
Be sure all the maintenance stuff is done first, including valve adjustment is correct.

Sounds like it could be lean at full throttle with load (falling flat on face like that) - check that is has a stock, not aftermarket filter on it. If aftermarket try going back to stock and seeing if corrects it. Otherwise try going up one size (or cleaning the mains first if this is a new problem not related to the can changes) the main jets.

 

Thanks Bill, When in nuetral or clutch pulled in motor rev's freely to redline without a hitch. Could there be a clutch problem?

 

doesn't sound like it. that would usually be rise in RPM not stuttering. I'd think a lean situation.