Honda CBR400F (NC17) 1983

December 1983, The First Generation "Honda CBR400F" (NC17) Launched - A Naked Sports Bike with a DOHC 16-valve 4-cylinder Engine

Honda CBR400F 1983
1983 Honda CBR400F (NC17) photo. Square headlamp and without fairing.
Honda CBR400F is a naked sports bike equipped with a newly designed air-cooled 4-cycle DOHC 16-valve parallel 4-cylinder engine (399cc) that uses a rotation response type valve suspension mechanism (*REV). Released on December 20th, 1983.

The engine installed in this Honda CBR400F adopts an epoch-making REV mechanism that changes the number of operating valves to 4 valves in the high rpm range and 2 valves in the low and medium rpm range according to the engine speed. Furthermore, by adopting a resonance chamber that rectifies the inflow air to improve intake efficiency, and by adopting a 4 → 2 → 1 → 2 exhaust system that achieves both improved exhaust efficiency and quietness, 58PS/12 It has a high output of 300r pm and a strong torque characteristic of 3.6kg-m/11,000rpm, and realizes excellent fuel economy of 40km/L (60km/h constant-land driving test value).

The body design uses a newly designed double cradle frame, which is a newly designed square cutting pipe that pursues light weight and high rigidity by computer analysis, and a lightweight and high rigidity NS Comstar wheel. Equipped with a triple (two front and one rear) flat disc brakes that are even lighter and have a newly designed design. In addition, the dual piston caliper is adopted, the more compact TRAC (brake torque response type anti-dive mechanism) is adopted, the large diameter 35φ front fork with air is used, and the well-established Prolink that demonstrates excellent road surface followability. It has a full range of equipment suitable for high-performance sports bikes, such as the adoption of a rear suspension.

*Abbreviation for REV = Revolution Modulated Valve Control. 4 valves operate in the high rpm range, and 1 cylinder in the low/medium rpm range, one on the inlet side and one on the exhaust side, depending on the engine speed. A valve system in which the valves stop operating and become two valves. This is because the sensor detects the engine speed, and the hydraulic piston built in the rocker arm divided into two moves to separate and connect the rocker arm, and switch the 4 valves ← → 2 valves operation automatically. When the 4-valve is operated, high rotation and high output are produced, and when the 2-valve is operated, the air-fuel mixture is less blown out and the flow velocity is improved. It is an epoch-making system that realizes high swirl effect and excellent filling/combustion efficiency.

Other main features of Honda CBR400F

  • Equipped with an oil cooler to improve cooling efficiency.
  • Adopts a square headlight (60W/55W) with a fearless design.
  • Adopts front 16-inch wheels.
  • Uses a silencer with sachilite plating.
  • Uses a meter panel with a fuel meter that is easy to see and functionally designed.
  • Uses a racer-image fuel cock lever laid out on the side of the tank.

1983 Honda CBR400F Specifications

Overall length (m)2.035
Overall width (m)0.710
Overall height (m)1.075
Wheelbase (m)1.390
Minimum ground clearance (m)0.140
Seat height (m)0.780
Vehicle weight (kg)193
Dry weight (kg)176
Riding capacity (persons)2
Fuel economy (km/L)40 (60km/h constant-land driving test value)
Climbing ability (tan θ)0.46 (about 25 degrees)
Minimum turning radius (m)2.6
engine modelNC07E/Air-cooled 4-cycle DOHC 4-valve 4-cylinder
Total displacement (cm3)399
Inner diameter x stroke (mm)55.0 × 42.0
compression ratio9.6
Maximum output (PS/rpm)58/12,300
Maximum torque (kg-m/rpm)3.6/11,000
Carburetor modelVE53
Starting methodSelf
Ignition methodFull transistor
Lubrication methodPumping splash combination type
Lubricating oil capacity (L)3.0
Fuel tank capacity (L)18
clutch typeWet multi-plate coil spring
Transmission typeAlways meshing 6-stage return
Gear ratio1st speed2.769
2nd speed1.850
3rd speed1.478
4th speed1.240
5th speed1.074
6 speed0.965
Reduction ratio 1st/2nd2.565/3.142
Caster (degree)27° 00′
Trail (mm)98
Tire SizeFront100/90-16 54H
Rear110/90-18 61H
Brake typeFrontHydraulic disc
RearHydraulic disc
Suspension method(Before) Telescopic
(Rear) Swing arm (Prolink)
Combined use of cylindrical air springs for both front and rear
frame formatDouble cradle

Honda CBR400F Price

The national standard cashprice of Honda CBR400Fwhen it was in new condition in Japan is : 539,000 yen. (Excludes Hokkaido/Okinawa and some other remote islands).
The sales plan is : Scheduled for 30,000 units (domestic/annual).

Check also the successor Honda CBR400F Endurance with half fairing and two circle headlamps, released in 1984.


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