My friend bought this clutch new in 2001 and had it modified by erlandson machine in Montana. He used it a year before he switched sleds. It's been in the garage ever since. The clutch mods include adjustable angle helixes and externally adjustable sheave width so you can just turn the knob a little when you're belt is getting thin instead of putting on the spare belt. Works great. $200 includes shipping. 406-581-7089