Yamaha xj400 (1980-81)

The Yamaha XJ 400 Seca motorcycle was produced in 1980-1981 with a four-stroke transverse four-cylinder DOHC engine. The capacity of the bike is 398cc or 24.2 cubic inches, with a bore x stroke of 51 x 48.8 mm. The engine is air-cooled with a compression ratio of 9.7:1 and has an induction of 2x 34mm Mikuni carburetor. The ignition system is battery-powered inductive and the bike has an electric starting mechanism. The maximum power of the bike is 45 hp or 32.8 kW at 10000 RPM and the maximum torque is 3.5 kgf-m or 25 lb-ft at 8000 RPM. The bike features a 6-speed transmission and a chain final drive.

The front suspension of the Yamaha XJ 400 Seca consists of 35mm telescopic forks with a front wheel travel of 142mm or 5.6 inches, and the rear suspension is a single shock with adjustable spring preload with a 96mm or 3.8-inch rear wheel travel. The front brakes are single-disc with a 1 piston caliper, while the rear brakes are drum. The front tire is 3.00-19, and the rear tire is 110 90-18. The dry weight of the bike is 176 kg or 388 lbs and the fuel capacity is 15 Litres or 3.9 US gallons.

The standing 1/4 mile time for the bike is 14.0 seconds at a speed of 90.5 mph, and its top speed is 162.5 km/h or 101 mph. Overall, the Yamaha XJ 400 Seca is a powerful motorcycle with impressive specifications for its time.


Technical specifications:

Make Model: Yamaha XJ 400 Seca

Year: 1980 – 81


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

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