Most of what everyone said is true, except 91-92 QR250's had a different swingarm and rear shock linkage, they also have a gusseted frame in front which makes them much less likely to have the frame crack. One other thing the 87 had a larger reed cage, smaller bridged intake port, as oppossed to an unbridged intake on the 88-92, and the exhaust port is lower on the 87 which makes better low end, (less top end). to look at port mapping go to this web site http://www.geocities.com/kiwi_craig/LTengdata.htm.

My 92 has been great, in the last year I have gone through every bearing on the machine, but I think that was due to neglect by prior owners. It will stomp virtually every 400-440EX out there, it handles great and its a ton of fun.