Yamaha xj400 (1981)

The Yamaha XJ 400D motorcycle was produced in 1981 and had a four-stroke, transverse four-cylinder engine with a capacity of 398 cc or 24.2 cu-in. It featured a compression ratio of 9.7:1 and was air-cooled, with 2x 34mm Mikuni carburetors and battery-powered inductive ignition. The electric starter produced a maximum power of 45 hp or 32.8 kW at 10000 rpm, and a maximum torque of 3.5 kgf-m or 25 Nm at 8000 rpm. The transmission had 6 speed gears, and the final drive was a chain design. The front suspension was made up of 35mm telescopic forks with a wheel travel of 142mm, and the rear suspension was a single shock design with adjustable spring preload and a wheel travel of 96mm. It had a single disc, 1-piston caliper front brake, and a drum-style rear brake. The front and rear tires were 3.00-19 and 110 90-18 respectively. The dry weight of the motorcycle was 176kg or 388lb and the fuel capacity was 15 liters or 3.9 US gallons. The top speed was recorded at 162.5 km/h or 101 mph, and it took the bike 14.0 seconds to travel a standing 1/4 mile at a speed of 90.5 mph.

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Technical specifications:

Make Model: Yamaha XJ 400D

Year: 1981

Engine: Four stroke, transverse four cylinder. DOHC

Capacity: 398 cc / 24.2 cu-in

Bore x Stroke: 51 48.8 mm

Cooling System: Air cooled

Compression Ratio: 9.7:1

Induction: 2x 34mm Mikuni carburetor

Ignition: Battery powered inductive

Starting: Electric

Max Power: 45 hp / 32.8 kW @ 10000 rpm

Max Torque: 3.5 kgf-m / 25 [email protected] 8000 rpm

Transmission: 6 Speed

Final Drive: Chain

Front Suspension: 35mm Telescopic forks

Front Wheel Travel: 142 mm / 5.6 in

Rear Suspension: Single shock, adjustable spring preload

Rear Wheel Travel: 96 mm / 3.8 in

Front Brakes: Single disc 1 piston caliper

Rear Brakes: Drum

Front Tyre: 3.00-19

Rear Tyre: 110 90-18

Dry Weight: 176 kg / 388 lbs

Fuel Capacity: 15 Litres / 3.9 US gal

Standing 1/4 Mile: 14.0 sec / 90.5 mph

Top Speed: 162.5 km/h / 101 mph