I have an 85 or 86 cr250 for sale. Back when they still had power. The motor has had brand new machine work done to it. New piston and bearings. The head has been milled, nickasil plating bored out and sleeved. Machine work from ridge reamer. The crank was sent out to crankworks in Arizona and rebuilt with new bearings and a new rod. Also new crank bearings in the case. I have a full gasket set to go with, the new piston as well as the repair manual. I have over a grand in the machine work and new parts alone. The bad, when i wass putting the motor back together, stripped 2 case bolts out and i just lost interest. Needs to be drilled with a helicoil repair or welded and re tapped. Any machine shop should be able to complete this for very cheap. I just havent had the time.