in its day, the 1987 CR250 was hailed as one of the best production MX bikes ever to grace the planet.
I loved mine, and will get another to restore and race one day- nice power, good suspension and good turning- mine even had gold rims!!! damn i loved that bike, but some scumbag stole it.
a couple of things, the clutch case seemed to corrode with the coolant- just check that. also, on the powervalves, just check they have the wierd looking circlip attached- sometimes they would come loose and the PV would wear the cylinder- you can check by popping the cover on the side of the cylinder.
be careful to line up the PV governer when doing a top end job.