NSR-WORLD.COM
NSR-WORLD.COM
On the 1st of October 1986, the NSR250R MC16 was launched at the Tokyo Motor show.
Conceived as a "complete replica" of Freddie Spencer's 1985 championship winning RS250RW NV1A, the MC16 was arguably the greatest Sports Production "race replica" 250.
Although released in 1986, the MC16 is officially a 1987 model, but can often be referred to as ’86 in a lot of Japanese/HRC literature.
1987 NSR250R [MC16]
Click to enlarge…
Central to the concept of the NSR250R was the all new, Grand Prix derived 90° crankcase induction V-twin motor, with a 54×54.5mm “square” bore & stroke, that would remain largely unchanged for its 10-year priduction run, and ultimately go on to form the basis of the next generation of RS250R NF5 customer GP bike for 5 years.
The MC16’s 28mm Keihin TA10 flat slide carburettors now sat behind the motor in a compound assembly, and as with the RS250RW NV1A, fed directly into the crankcases. The compact, naturally balanced 90° V-twin motor was inclined at 20° in the frame to lower the centre of gravity.
Again, as with the NV1A, the transmission was a quick-change full cassette system, held in place by just 6 screws; virtually identical to that of the RS250R NF5 GP bike that would soon follow.
The final, and most notable point of the new model’s engine was the introduction of the RC Valve, as seen during the second half of the 1986 Grand Prix season on both the NSR500 NV0C and NSR250 NV1B. The system was actually developed by the NSR250R design team, and poached by HRC for use on the GP bikes!
From our Honda approved NSR-WORLD English Service Manual:
“A valve is installed in the exhaust port of the cylinder, which moves up and down according to the engine speed. By changing the height of the exhaust port, the exhaust timing is changed, and the output is improved from low to high RPM.
The entire system is controlled by a control unit. The engine speed is detected from the CDI of the front cylinder, and current is sent to the servo motor according to the engine speed and the resistance value of the servo motor.
The servo motor is operated by the current from the control unit and controls the RC valve via the control cable.”
RC Valve was utilised on the MC16 a full year before it found its way onto the 1988 RS250R NF5B consumer GP racer.
The MC16 chassis saw a number of improvements over the previous NS250R MC11.
Immediately apparent was the RS250RW “ULF” inspired “I-beam” frame and box section swingarm. The motor was mounted directly to the frame, further increasing stiffness of the chassic.
The front-end no longer used TRAC anti-dive, as seen on the NS250R, but now featured twin fully-floating 256mm discs as opposed to the NS250R’s solid fixed discs. The rear-end once again used the Pro-Link rising rate setup with non-adjustable Showa shock absorber, with a fixed 220mm rotor. The chassis was finished off with a set of 3-spoke “S” design wheels manufactured by Enkei.
A sleek aerodynamic fairing and seat cowl wrapped the chassis, painted in the same red & white of the ’87 Team HRC 500s of Keiji Kinoshita [All-Japan] and Freddie Spencer [WGP], and a rear hugger just like the one found on Freddie Spencer’s RS250RW was fitted to protect the rear shock from debris, adding to the overall “racer for the road” appearance. Six months after it’s release, a blue and white livery was introduced, based on the All-Japan 250s of Masaru Kobayashi and Masahiro Shimizu [Ajinomoto Honda Racing].
Weighing in at just 125kg “dry”, the NSR250R MC16 was the lightest 2-stroke super sports bike in the 250cc class.
SPEC: 1987
NSR250R [MC16]
Engine type: 90-degree V-type two-cylinder
Capacity: 249cc
Bore x Stroke: 54.0 x 54.5mm
Power: 45PS @9,500rpm
Torque: 3.6kg-m @8,500rpm
Weight: 125kg (Dry)
Price ¥559,000 (1987)
SPEC: 1987
NSR250R [MC16]
Engine type: 90-degree V-type two-cylinder
Capacity: 249cc
Bore x Stroke: 54.0 x 54.5mm
Power: 45PS @9,500rpm
Torque: 3.6kg-m @8,500rpm
Weight: 125kg (Dry)
Price ¥559,000 (1987)
SPEC: 1987
NSR250R [MC16]
Engine type: 90-degree V-type 2-cyl
Capacity: 249cc
Bore x Stroke: 54.0 x 54.5mm
Power: 45PS @9,500rpm
Torque: 3.6kg-m @8,500rpm
Weight: 125kg (Dry)
Price ¥559,000 (1987)
