im looking at an 01 rmk 800 with a can and 144"x 2" track with 3000 miles for 3500 and was wondering if they are a good sturdy sled or not

the 800 is a good pull and its a pretty good sled. pay 3000 at the most

it was bout 3000 before taxes and license, thanks

I forget if that's in a Gen 2 chassis or an Edge. The Edge RMK's were much nicer, though the Gen2's are still pretty decent.
Find out if the crank has been done on it. The crank's tend to go at the PTO end, not a huge deal if you catch it as soon as it goes, and when if you get the crank redone there's a heavy duty crank with a double wide bearing on the pto end that will fix the problem once and for all.

The 800 motor is really sweet other then that. Pulls like a tractor, good power through out, easy to clutch, and not bad on fuel. Well, not great on fuel either, but acceptable.

The 144 is a very good length, probably the best all round length for an off-trail machine.

thanks any idea on the cost of the crank and time to do it?

how about hte 05 rmk 800 with a 144 track for 7000 no miles 1 year waranty or the 05 700 xc 159 track no miles and 1 year waranty for 6500