A brief history of the Honda NSR 250

The NSR250R is a two stroke V-twin street bike that was introduced by Honda as a street legal replica version of the NSR250 (also known as the RS250R), which was introduced in 1984 to race in the Grand Prix motorcycle World Championship.

The earlier generation of the street bikes quickly amassed a following within the Japanese racing community as it was the easiest of the two strokes in its class to de-restrict. Honda had capped the maximum output at 45 hp at 9500 RPM to meet Japanese road regulations.  Although this was still impressive for a bike of its displacement (even though it trailed behind the Suzuki RGV250 in terms of out of the box power) , the unlocked ECU presented the option to significantly increase (and in some cases double) the horsepower, which contributed to its cult following.

The first generation of the street legal NSR, the MC16,  was introduced in 1987. Staying true to the GP bike it was modelled after, there were some common features such as a lightweight frame and the adoption of a cassette transmission. The main benefits of this was relative ease in servicing or replacing the transmission as well as adjustments to the gear ratios. The MC16 also debuted the new electronically controlled RC Valve. Under this new design, valves were employed in both cylinders rather than just one, which increased its effectiveness and efficiency. The new technology sought to increase output throughout the entire range of the engine speed by changing the exhaust timing.

The next generation of the NSR, the MC18, was released in two phases in 1988 and 1989. The earlier model featured a computer controlled carburetion system, which was unheard of at the time for a street bike. The first SP model was also introduced in 1988, which featured upgrades, both aesthetic and functional. A dead give away that you were in the presence of an SP model was the new magnesium rims and Rothmans colors that were introduced for this model.  The later MC18 model was released with a more aerodynamic windshield as well as a new ignition map where functions such as ignition timing and the RC valves were controlled by a single unit which improved the overall efficiency.

The MC21 model was released in 1990 with a flashy new design that was modelled after the GP bike. I particular, it featured a Gull Arm swing arm and frame design that was modelled after the GP bike. The MC21 R model became the best selling bike in Japan. There were 2 other differences made during this generation; the SP model now utilized a dry clutch, and an SE model were available. The SE was very similar to the SP model, but more affordable because it did not have the magnesium wheels.

Finally, the last generation of the NSR was the MC28 and was produced from 1994 to 1996. This model featured a sophisticated new “smart card” technology that controlled the ignition characteristics . This was marketed as increased riding efficiency as one of several cards could be used to correspond to different track and street riding conditions. However, skeptics immediately recognized that this may have been Honda’s way of marketing a less powerful bike (to meet with ever more stringent Japanese regulations) that became more difficult and costly to de-restrict. The R model was discontinued in 1996, leaving only the SE and SP models available.