Not too sure about the excess fueling. Especially after coming in off the track with a nice coloured plug chop?? Maybe check the float levels?

That 7-8.5k rev range is where the power valves and air correction solenoids really kick in.
I would be tempted to check these out to make sure they are working properly?

Sorry, I can't be of much help on this one.
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...