If it isn't on the tank, I wouldn't know where to even find it! The old oils used to be anywhere from 32-1, 40-1 or 50-1! I would use a good oil at 40-1 to start with and if the plugs don't show oil deposits go up to 32! If they foul easy then down to 50!
I had a 79 whip my buddy a sting we both ran 40 to 1 mine burnt 8 pistons+ spit out seals my buddys sting ran for years+years trouble free, just read the plugs on the first tank of fuel to be sure,clean the carbs on that sled if it has set at all!!!
1992 Ski Doo Mach 1 (SC-10/2 suspended) March '07 SF.com Sled of the Month! (Lost in fire 4-7-13)
1992 Ski Doo Mach 1 original 2006 Ski Doo MXZ 500SS
1999 Ski Doo MXZ600 Webmaster Evergreen Valley Snowmobile Club SledNH.com Moderator