The Suzuki GSX-R400 has been developed as a new generation motorcycle to the GSX models. The Suzuki GSX-R400 was released in 1984, being based on Yoshimura’s TT-F3 racer GS1000R. The GSX-R400 was the first mass produced light weight racer with a liquid cooled four cylinder engine.
The Suzuki GSX-R400 (initially called GSX-R in Japan, internal model code GK71B) was released in March 1984. It was the first mass-produced light-weight racer replica with an aluminum cradle frame and a liquid-cooled inline-four DOHC engine with four valves per cylinder.
The, in those days, amazing machine was based on Yoshimura’s TT-F3 racer GS1000R. The competitors, Yamaha FZ400R and Honda CBR400R were 13—31 kg (29—68 lbs) heavier than the new and quick GSX-R.
Compared to other bikes of the time, the Suzuki GSX-R 400 1984 was very light and the 4-piston brakes at the front and the 2-piston rear brake was more than adequate for the 152 kg (334 lbs) light street racer. The bike was quick to handle, the engine with 4-1 exhaust system was powerful for its size and made the GSX-R the fastest bike in its class. With the maximum power output 59 hp and 152 kg (334 lbs( dry mass, the power/weight ratio (2,57 kg/hp) was even better than Suzuki’s incredible 2-stroke racer, RG250 Gamma. The GSX-R400 started a new era, it was the fastest and best-handling 400cc bike ever made.
The water-cooled inline-four four-stroke had double overhead camshafts and four valves per cylinder. The GSX400FW (presented the previous year) had the same principal engine specs but lower power output and the GSX-R400’s new engine with its 66 kg (145 lbs) was 10 kg (22 lbs) lighter. 12,000 maximum revs.
Suzuki GSX-R400 1984 Specifications
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Dimensions and dry mass
Type (frame code): GK71B
Overall length: 2,090 mm (82.3 in.)
Overall width: 710 mm (28.0 in.)
Overall height: 1,185 mm (46.7 in.)
Wheelbase: 1,425 mm (56.1 in.)
Ground Clearance: 135mm (5.3 in.)
Dry mass (weight): 157 kg (334 lbs)
Engine type: Liquid-cooled DOHC inline-4, 16 valves, TSCC
Bore x stroke: 53,0 mm x 45,2 mm (2.087 x 1.780 in.)
Piston displacement: 398 cc
Compression ratio: 11,3 :1
Maximum power: 59 ps/ 11,000 rpm
Maximum torque: 4,0 kg-m/ 9,000 rpm
Maximum speed: 175 kph
Starting system: Electric starter
Lubrication system: Wet sump
Carburetor: AISAN AS27VW x 2
Clutch type: Wet multi-plate
Transmission type: 6-speed constant mesh
Gearshift pattern: 1-down, 5-up
Primary reduction ratio: 2.212
1st gear ratio: 3.166
2nd gear ratio: 2.125
3rd gear ratio: 1.631
4th gear ratio: 1.333
5th gear ratio: 1.173
6th gear ratio: 1.083
Final drive: 3.066 chain
Frame type: Aluminum angular pipe double cradle
Caster: 27° 25′
Trail: 96 mm
Front suspension: Telescopic, coil spring, oil dampened with anti-dive
Rear suspension: Full floater suspension system, spring pre-load fully adjustable, oil dampened
Front brake: Dual hydraulic disc, four piston calipers
Rear brake: Single hydraulic disc, dual piston calipers
Front tire dimensions: 110/90-16 54h
Rear tire dimensions: 110/90-18 61h
Ignition type: fully transistorized
Ignition timing: 15º BTDC below at 1650 r/min and 35º BTDC above 3.500 r/min
Spark plug: ND U24FS-U or NGK C8HA
Battery: 12V 39.6 kC (11Ah)/10HR
Generator : Three-phase A.C. Generator
Headlight: 12V 35/35w x 2
Power/weight ratio: 2,57 kg/ps
Center stand: Yes
Fuel tank: 18 l.
Reserve: 3.5 l.
Engine oil: 2.6 l.
Front fork oil (each leg): 397 ml.
Cooling solution: 2,185 ml.
Suzuki GSX-R400 1984 Image Gallery