I'm aware an Indy is a snowmobile.
I figure a few must know something about them.
Is a older Indy 500 a good sled?
Is it the same as a Sprtsman 500 engine?
Why do snowmobiles go so much faster?
Thanks!

 

Completely different motors , twin cylinders , 2 cycle on the snowmobiles , single cylinder , 4 cycle on atv's , the snowmobiles are 488cc as I recall . I had five of them through the years , very good mechanically .
The suspension on a 1989 is primitive by even late 90's standards , I would look for a sled no older than 1997 , they had a far superior suspension than the one you're looking at .

 

your comparing apples to oranges when it comes to sleds vs atvs for sure as they are totally different engines and set ups. if you where to have the same power to weight ratio then the atv would be extremely fast lol. around 89 or 90' the 500 fugi had issues w/ crank bearing from a flaw in the oil passage design so the newer ones are a little better. the one thing I will say is the 500 (488 cc liquid) was one of Polaris best and dependable sleds as the 500 sportsman engines are in the atv world.

 

an indy 500 is an awesome machine if its in good shape. i had the indy trail deluxe of the same year (approx), which had the same engine but was fan cooled. i could get 80-90 mph on a cold day and a good surface, but i was always envious of the indy 5s. they had the low sporty windshield (looked sweet, but was COLD), and were faster