Looks to be a 2000 Enduro Sport (does it say 'Sport' under the FSR on the seat mast? I can't read it, even with a little Photoshop resampling). The bad news: it's missing some parts . The good news: the same rear triangle was used on the Comp, Expert, Pro and more than a few FSRs on either side of that model year - - as was the swing link. Plus there were aftermarket swing links (MRP, BETD) that could stretch it out to 6-6½" travel. And the shock was a fairly-common 6½" eye-to-eye/1½ stroke.

If you have a line on any/all of those parts, yeah it's a nice little frame. If you don;t, you could spend your life on eBay tracking it all down and should pass.