I've had relatively good luck with my first year model 2002 Sportsman 700 and am very happy with it.

I have replaced the carb boot/adaptor (before it cracked thru). Check that, the rubber gets weathered/dry rotted bad on some and may crack through.
And the hall speedo sensors sometimes go out ($50 part, p/n 4010298), its at the right front wheel rotor and has a wire going up to the pod.

Also the water pump cover should be a metal replacement of the leaky original plastic cover.
This was a Tech Service Bulletin for early models in '02 and some '03's.

The crank breather should be omitted for colder climates, this was also a Tech Service Bulletin (TSB).
The TSB is #S-03-05 and the part # is 2202744

Also some machines, mostly '03's have cold weather start jetting updates, both of the TSB's and the jetting should have been taken care of under warranty.

Jim