1981 Maico 250. Frame serial is 350xxxx. Engine serial is MT350xxxx. Very little known history. At some point - the top-end was being refreshed. Piston reads 90 (over standard). The top end was never buttoned up correctly (no head gasket) Plan to tear down and inspect. The frame has been re-enforced at the "Y" junction above rear shocks. (Nice job) This is a decent "core" bike - build into a race bike and/or restore. Bike is listed locally. See Pictures ... Ask Questions.