I have a PDF I got off eBay last year of the Clymer shop manual that covers the 1990-1995 Ski-Doo Formula MX. Formula Plus, Formula Mach and Grand Touring models. I also have a PDF of the operators manual for the 1990 Formula, Mach 1, MX/MX LT, Plus/Plus LT, If anyone needs a copy of each one, or both, let me know and I'll help ya out.
1990 Ski Doo Formula Plus
Some people are like Slinkies - not really good for anything, but you still can't help but smile when you see one tumble down the stairs!