clutching issues 99 powder special

[jeapadrenaline]

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.

 

[RCR3]

What altitude are you at when running these tests?
70-75MPH is real fast for a powder special 600!
What is the speed up hill in 6-12 of powder?

 

[diggerdown]

It's a 90 hp 600, how much were expecting out of it? Sounds to me like it is running very well.

 

[firecat99]

Try going back to the yellow/white stock spring, or heavier weights. These motors like to be spun around 83-8400rpm with a single pipe and around 86-8800 with pipes (those really wake up the motor).

What is your RPM engagement?

I was having this problem a few seasons ago when i went to my 720 big bore and my final results were not even close to what D&D recommended nore did it work like it should have.
But i ended up using F5 50.5 gram weights with yellow/white primary. Secondary was a red spring in the middle with a 49degree that came stock. I could not get the 57-50 to work right on these motors for some reason.

But in 600 form mind you mine was carbed I had no problem spinging 8400rpm and do 90+mph with a 1.25" paddle. When i turned it into a 136x2" i geared down from 19-39 to 19-44 as was spinning what your spinning but was pulling rpm right so power band was broader.

 

[jeapadrenaline]

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.

 

[RCR3]

Sorry to hear that ,tough times! You will get back up there if you haven't already!
GOOD LUCK!