| Year | 1987 |
| Bore x Stroke | 54 x 54.5 mm |
| Capacity | 249 c / 15.2 cu-in |
| Clutch | Wet plate |
| Compression Ratio | 6.2 : 1 |
| Cooling System | Liquid cooled |
| Dimensions | Length 2035 mm / 80.1 in Width 705 mm / 27.7 in Height 1105 mm / 43.5 in |
| Dry Weight | 125 kg / 275.5 lbs |
| Engine | Two stroke, 90°V-twin cylinder, reed valve/exhaust valve |
| Exhaust | Expansion chamber, RC power valves |
| Final Drive | Chain |
| Frame | Aluminum tube type frame |
| Front Brakes | 2x discs 2 piston calipers |
| Front Suspension | Telescopic air valve semi-adjustable |
| Front Tyre | 100/80-17 52 H |
| Fuel Capacity | 16 Litres / 4.2 US gal |
| Gear Ratio | 1st: 2.846 / 2nd: 1.941 / 3rd: 1.500 / 4th: 1.272 / 5th: 1.136 / 6th: 1.045 |
| Ground Clearance | 135 mm / 5.3 in |
| Ignition | CDI |
| Induction | TA10A Carburetor Type |
| Lubrication | Injected 2-stroke oil |
| Max Power | 45 hp / 32.8 kW @ 9500 rpm |
| Max Torque | 35 Nm / 25.8 ft-lb @ 8500 rpm |
| Rake | 23° |
| Rear Brakes | Single disc 1 piston caliper |
| Rear Suspension | Rear: Pro-Link Single shock swingarm non-adjustable |
| Rear Tyre | 130/70-18 63 H |
| Related Links | Type I / Type II / Technical / nsr250.net |
| Road Test | Bike magazine Group test 1987 |
| Seat Height | 750 mm / 29.5 in |
| Starting | Kick |
| Trail | 87 mm / 3.4 in |
| Transmission | Constant Mesh 6-speed |
| Wet Weight | 141 kg / 310.8 lbs |
| Wheelbase | 1360 mm / 53.5 in |
