Sled is a 1988 panther 500cc fan cooled twin, single carb (about 49 hp-??). Manual says engagement RPM is 3600-4000. Peak RPM is 6800-7000. Original clutch was a HEX clutch. The HEX clutch ramp is: p/n 0146-414., and the spring is GREEN p/n 0146-068. The weight in the HEX is p/n 0146-278. Belt width: 1 3/8".
My question: I switched to a Polaris P85 primary clutch (dated 1998) and I need advice on the spring & weights to use in it. Weights are 10-64 in this P85 right now, and it does have an ORANGE spring and I was told that the engagement RPM is very high,,,,,,,,so I will almost surely have to re-calibrate.
I am not set up to grind weights or anything fancy,,,so a bolt on set-up would be nice. I assume Polaris parts would be the best ???
I'll be using the sled for trail riding (sometimes aggressive, relatively speaking), and I am at sea level, and I weigh about 230 lbs.

Thanks for any help.

Just go to polaris web site and use thier parts manual to look up parts for their 550 fan.

Several days ago I did check to see what weight/spring combo Polaris used in stock machines such as the Indy Trail 488cc fan 1989-1999, in addition to the sport 550 fan model. I focused on the Indy Trail because it is the closest to my 500 fan cooled engine AND it uses a P85 clutch. HOWEVER, the Indy Trail has different gearing in the chaincase than I do AND they use a 9 tooth track sprocket where mine is 8 tooth,,,,,so I don't know if the INDY TRAIL's overall gear ratio is the same as mine and therefore if the weight/spring combo would work on mine. For the record the 1999 TRAIL used 10-AL weights (53 grams) and a Red/White spring. I chose the 1999 Indy Trail as an example because the date on my p85 clutch is 1998 and is probably the same as the 99 Indy Trail clutch. (the indy trail is dual carb, mine is single, so the indy trail is probably 5-10 more hp than mine also).

one tooth or a couple hp shouldn't make a differance, ,,I've ridden a "99 indy trail,, it's a mild clutch set up.