Yamaha XJ650 (1981)

The Yamaha XJ 650 Seca released in 1981 has a four-stroke, transverse four-cylinder, DOHC, 2 valves per cylinder and a capacity of 653cc/39.8 cu-in. The Hitachi carburetor induction, transistorized ignition, and electric start give it a maximum power of 71 hp/51.8 kW @ 9400 rpm and maximum torque of 57 Nm/42 lb-ft @ 7500 rpm. It has a 5-speed transmission, wet multi-plate clutch with 7 steel 8 friction plates, and a shaft final drive with a gear ratio of 1st 2.187 (35/16), 2nd 1.500 (30/20), 3rd 1.153 (30/26), 4th 0.933 (28/30), 5th 0.812 (26/32). The frame is a tubular steel dual cradle frame and has a 36mm Kayaba fork, 142mm/5.5in front wheel travel, and dual Kayaba shocks in the rear with a 93mm/3.6in rear wheel travel. Its front brakes consist of 2x 268mm disc 1 piston calipers while its rear brakes are drums. It has a wheelbase of 1445mm/56.8in, a seat height of 780mm/30.7in, a ground clearance of 145mm/5.7in, and a dry weight of 206kg/465lbs. The fuel capacity is 19.5 liters/5.1 US gal and its average consumption is 48.6 mpg. Its standing 1/4 mile is 12.6 sec/171 km/h.

Technical specifications:

Make Model: Yamaha XJ 650 Seca

Year: 1981
Engine: Four stroke, transverse four cylinder, DOHC, 2 valves per cylinder,
Capacity: 653 cc / 39.8 cu-in
Bore x Stroke: 63 52.4 mm
Cooling System: Air-cooled
Compression Ratio: 9.2:1
Induction: 4x 32mm Hitachi carburetors
Ignition: Transistorized
Starting: Electric
Max Power: 71 hp / 51.8 kW @ 9400 rpm
Max Torque: 57 Nm / 42 lb-ft @ 7500 rpm
Clutch: Wet Multiplate; 7 Steel 8 Friction
Transmission: 5 Speed
Final Drive: Shaft
Gear Ratio: 1st 2.187 (35/16) 2nd 1.500 (30/20) 3rd 1.153 (30/26) 4th 0.933 (28/30) 5th 0.812 (26/32)
Frame: Tubular steel dual cradle frame
Front Suspension: 36mm Kayaba forks
Front Wheel Travel: 142 mm / 5.5 in
Rear Suspension: Duel Kayaba shocks
Rear Wheel Travel: 93 mm / 3.6 in
Front Brakes: 2x 268mm disc 1 piston calipers
Rear Brakes: Drum
Front Tyre: 3.25-19
Rear Tyre: 120/90-18
Wheelbase: 1445 mm / 56.8 in
Seat Height: 780 mm / 30.7 in
Ground Clearance: 145 mm / 5.7 in
Dry Weight: 206 kg / 465 lbs
Fuel Capacity: 19.5 Litres / 5.1 US gal
Consumption Average: 48.6 mpg
Standing 1/4 Mile: 12.6 sec. / 171 km/h