P/S
I am one of the other 3 that still ride the old powder special. I am glad there are other that still ride the old stuff, the younger generation needs to be aware of where their mountain sled heritage comes from. Mine is a 97 PS 580. Most of my riding occures at 5500 - 7000 feet. I have it set up with 19/40 gears, secondary clutch has been switched to a AC roller with 49 degree helix and yellow spring in position 2 hole. comet 108exp primary clutch with yellow/green spring and comet A-22 notched cam arms at 47 grams. It engages at approx 4800 rpms and shifts out at 8200 - 8300 rpms. I have also used A-1 cam arms ground to 48 grams. The A-1 offers better trail manners a stonger mid-range and an engagement at under 4000 rpms. The A-22 cam arms are much better at low end and work better in the powder. You may have to experement with helix angles and spring positions to dial in the proper shift rpm on your sled. The only engine modifications I have done are UFO's in the carb's, and wisco pistons. I have been using Blue Marble oil and found improved performance after a season of use. I still am using the AC altitude compensator and am jetted at 380 main, 25 pilot, and needle at position 2 (from the top). I will occationally jet down to 370 on warm (over 40 degree) days. I have switched the track to a 141 long 1.75 lug. I build a drop bracket on the rear suspension mount dropping the mounting hole 1.5 inches and moving it back 2.5 inches, the front mounting holes were moved back 2.5 inches. This allowed me to mount the longer track without using rail extensions and changed the track attack angle similar to rolling a chaincase. I found that the 2 inch lug track would have hit the front heat exchanger and would have required smaller drivers. The changes drastically changed the way the sled handles in the powder. I can boondock with the big boys all day long. I hope this was not too long and detailed but I have spent considerable time experimenting with this sled to get it where I wanted it. I can not afford to go out and buy a new or newer one. I have had this sled for 5 years and probably will be riding it another 5.