clutching issues 99 powder special

ok here it goes. i have a 99 powder special 600 EFI with D&D pipe and chip and also the PAC. i got the pipe and chip with the clutchkit a couple years ago and installed them but didnt ride at all last year.
went out today and got the fuel adjusted via PAC. runs good, has awesome power (for a 600 PS) plugs are perfect light chocolate brown.
problem is, RPM max out at 8thousand on the spot,and only pulling 70-75 mph thats on flat hardpack with about 2 inches powder covering.
i took a jiffy marker and marked the primary sheave and low and behold, the top 3/4 inch of the sheave is untouched. belt has a few miles on it so basically new.
primary spring is orange/white. weights are marked 10-54
secondary is grey in center hole, with helix 57-50
gearing is stock with reverse
can anyone give me some tuning ideas?

so i ran it today with track off ground.... still rpm maxed at 8000, but speed was up and belt pulled right to the top of primary.

i feel this sled could perform better, but i am all new to clutching.

Thanks guys, but i have since lost the sled due to bankrupty. Just hope the new owner, whomever he is, dont burn her up on the first ride. With the PAC and Chip/pipe i sure kept an eye on the egt gauges.
If anyone comes accross that sled, i may be interested in purchasing it back. Can't mistake it has purple LEDs inside headlight and in front suspension... total of around 500 pieces. I do miss that ole girl.