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High RPM cut out after 8500RPM

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  • High RPM cut out after 8500RPM

    I have an interesting problem. At WOT, about 7500RPM or higher I suddenly loose power or the bike bucks, almost feels like I loose a cylinder. If I slowly rev to redline in first gear I get the same result as on highway. Speed is irrelevant, gear is irrelevant. The bike has always been great and pulled hard. Instead of hitting a rev limiter at 9,XXXRPM and getting the typical rev limit sound the bike just suddenly bogs down. When I let off the throttle a little bit power comes right back. Other than that, the bike runs like a bat shit out of hell! Fires right up, will idle smoothly at very low RPM and if you snap the throttle revs quickly and drops right back down.

    On my other hawk I get the typical rev limiter sound. Now, the hawk that I am trying to troubleshoot I am assuming might have cams as it is quicker than the other and snappy. I am wondering if the cams act odd with the rev limiter and everything is maybe fine? Maybe the rev limiter just sounds that much different on this bike?

    Here is a video of the bike reving at idle:
    You can hear the lack of typical redline sound...

    Things off the top of my head I have already done:
    -New plugs, gaped to manual spec.
    -Carbs cleaned, slide boots replaced, carb boots replaced, new air filters, float level correct, carbs synced
    -Coil resistance(s) checked
    -Fuel pump flow rate checked per manual specification
    -New OEM ignition computer installed
    -I have ran to high RPM and hit the kill switch immediately when it bogged and removed the carbs and drained the float bowls to insure they both had proper amounts of fuel and they did.

    Does anyone have any thoughts as to what would cause this? I would assume if valves were out of adjustment idle would not be perfect and I would not have a perfectly snappy throttle. I am running out of ideas....

    PS. In CHARLESTON SC if anyone wants to come check it out lol.
    Attached Files
    Last edited by norbit2; 09-15-2022, 06:37 PM.