1989, 1990 and 1991 Mach 1 Serial Number Confusion

I bought my first snowmobile, a 1990 Mach 1, seven years ago off the local Craig’s List. I bought it because it was late March and therefore cheap. As a new rider of a rather tricky sled, it got banged up more than once and I decided last winter to rebuild it over the coming summer. While looking for parts, I found out some people consider this to be a desirable sled. I found an 89 parts sled with a good hood and bought that one only to find out the front suspension was different. I started watching things on-line and found a running 1990 Mach 1 xtc with a 91 formula hood on it that included a parts ski. So, I bought it. After an in-depth check, the one I just bought is in better shape than the one I already have. However, if other boards are correct, all tunnels have the first four tunnels’ numbers listing them as being 1989s. Titles of the skis indicate they are what I stated above. (89, two 90’s and a 91). So, three questions: 1. What years of skis do I actually have? 2. Which two would be the best to rebuild? 3. Would I be better off just selling the five skis and just finding a much newer runner? As additional background, I rebuild Seadoo jet skis and old boats for fun. I do not know anything about sleds beyond the motor so I am out of my depth. I respect all that you do so advice is welcome.



JLT1