The ’84 CR was the first of the “modern” era bikes, with water-cooling, linkage rear suspension, power valve-controlled and front disc brakes – all the underpinnings of a current 250cc two-stroke.
The early-to-mid 80s was the golden age of motocross. In six years left behind twin-shocks, drum-brakes and piston-port air-cooled two-strokes. The ’84 CR250R was the first of the “modern” era bikes, with water-cooling, linkage rear suspension, power valve-controlled exhaust port and front disc brakes – all the underpinnings of a current 250cc two-stroke. As such, it’s a popular choice for VMX enthusiasts as it can be competitive in both the pre-85 and pre-90s classes.
The CR250R’s motor makes startlingly good mid-top-end power that is a match for any 250cc two-stroke. The bottom-end is a little soft compared to today’s bikes, due mostly to the round-slide 38mm Keihen carby.
A swap to a Keihen 38mm PJ or PWK carb from a later model CR250R yields a boost in throttle response. The CR’s motor ran the steel bore inside the cylinder, and there are a range of pistons available for this bike.
The intake porting on the cylinder is quite large, which can contribute to cracked pistons on bikes that have too many hours on their top ends. I recommend freshening up the top-end every 20 hours or so just to be safe.
The big issue with these engines is the magnesium clutch cover and water pump housing. These get corroded and are virtually impossible to find new. Luckily, they can be repaired with epoxy filers and restored with a bit of work.
The handling and suspension on the 84 CR250R was its strong point. They steer very well, but can be a bit twitchy and are known for a bit of head shake at high-speed.
The fork soft and the shock is hard, so fitting the correct springs for the rider’s weight and maintaining the rear sag at 110-115mm is a must. The guys at Race Tech have developed some really good Gold Valve settings for the shock and their fork Emulator kit is a massive improvement.
Look out for
Keep the top-end fresh and power valve system free of carbon build-up and the power is impressive
The stock Nissin unit works great with a modern braided line fitted
Check the linkage when you first get the bike and grease it regularly. The link has a bunch of plain bushes in it and not too many bearings, so greasing is important
Be sure to check for water in the gearbox oil which is a sure sign the water pump housing needs fixing
Dial up the correct rear sag height of 110-115mm or the front end tends to get nervous
CR250R Price Guide
CR250R Market Equivalents