That's a pretty fair price. As far as miles, it depends on how he used it. If he was running mountains with it at full throttle all the time, then 3700 miles is gonna be quite a bit. Maintenance is a big factor too. For most trail sleds 3700 miles is not all that many. Top ends are usually rebuilt every 5-6k and a sleds full life is usually up to 10-12k miles.

My biggest suggestion is- BRING A COMPRESSION TESTER. Buy one, borrow one, rent one, whatever you need to do to get one. That will give you the best idea of what you're getting. Everything else is fairly easily replaceable, but a motor in need of immediate service will get spendy quickly. PSI can vary between each motor, but anything under 115 psi will need service sooner than later. Some motors run great on 120 psi for a long time. Other motors are designed to run 135-150 psi. I would say if you can get 120 psi or better in both cylinders you should be fine for a while.

 

The big problem with the SkiDoo 700 as well as the 800 is the grease packed main bearings on the crank. Many, many failures after 3000 miles. You can maintain the sled all you want but unless you open the engine up and re-pack the pto and mag bearings with Isoflex grease at 3000 miles you may be headed for trouble. And another thing, at 3000 miles the skirts on the pistons are collapsed considerably, they may be at the wear limit. The compression may be all well and good at 125psi but piston clearance is an important factor to consider. You can maintain perfect compression right up until the skirt breaks off the piston and punches a hole through the crankcase.
Jerry

 

Irondog is right. Tearing it down before something goes bad will save you tons of $$ in the long run. I would tear it down next summer and put in new crank bearings and new pistons. This way you prevent the most expensive problems and leave knowing your engine will be good for a long time. New cranks and bore work is expensive to say the least. If that bearing fails you're talking about a new crank running at least $700 for the crank itself.

I'd say you're due for a rebuild either this season at 5k miles or next summer regardless. Without any bore or crank work (just pistons, rings, and crank bearings) a motor rebuild should be about $400.

All in all, I wouldn't worry about it during your purchase and go ahead and get it if you like it.

 

double post