You can find more parts for your unit using our Year-Make-Model. Or use our email contact form as we may have this part in the yard on another unit.OEM Part #(s) 420480246 or 417222257 A USED primary inner fixed sheave from a 1991 Skidoo Snowmobile FORMULA MACH 1 - check our fitments for more units this item will fit. We also sell new aftermarket parts - send us a parts request for a quote.Fitment Snowmobile 1991 Ski Doo FORMULA MACH I 1991 Ski Doo FORMULA MACH I X 1991 Ski Doo FORMULA MACH XTC 1992 Ski Doo FORMULA MACH I 1992 Ski Doo FORMULA MX 1992 Ski Doo FORMULA PLUS 1992 Ski Doo FORMULA PLUS E 1992 Ski Doo FORMULA PLUS X 1992 Ski Doo FORMULA PLUS XTC 1992 Ski Doo FORMULA XTC 1992 Ski Doo FORMULA XTC E 1992 Ski Doo FORMULA XTC II 1992 Ski Doo FORMULA XTC R 1993 Ski Doo FORMULA MX 1993 Ski Doo FORMULA MX 2 1993 Ski Doo FORMULA PLUS 1993 Ski Doo FORMULA PLUS 2 1993 Ski Doo FORMULA PLUS E 1993 Ski Doo FORMULA PLUS EFI 1993 Ski Doo FORMULA PLUS X 1993 Ski Doo FORMULA PLUS XTC 1993 Ski Doo FORMULA XTC R 1993 Ski Doo GRAND TOURING 1993 Ski Doo SAFARI DELUXE 1993 Ski Doo SAFARI L 1993 Ski Doo SAFARI RALLY 1993 Ski Doo SKANDIC 503R 1993 Ski Doo SKANDIC 503R SLT 1993 Ski Doo SKANDIC II 377 1993 Ski Doo SKANDIC II 377 R