Topic: 400f loss of power at 9k

[themotoworks]

just went through my 400f carbs because i was suspicious of the boots not being very well lined up near the clamps, so I took everything off and reconnected the boots perfectly then plopped the carb unit back on the bike and tightened everything up.  this made the idle perfect, spot on exactly and didn't change after the engine got hot.  now here's the rub, i now notice that that perfect honda4 engine tone, that beautiful ringing of an exhaust note, is perfect until about 9k, then it kinda "flattens" and i guess becomes more staccato, and the power seems to drop off there too, on the highway it really doesn't want to go over 75 now, when before i had hit 100 on it... I'm thinking maybe the carb was tuned with the boots leaking?  not sure, need some expert advice

[WFO]

Check all your vacuum lines.

[Frankencake]

You might be the victim of valve float.  Check that your valve clearances are within spec.  This kind of high rev power loss could be caused by over tight or sloppy valves.

[themotoworks]

vacuum lines are unobstructed... could be the valves, seemed to start happening after i worked on the carbs though, didn't notice the problem before