Object StatementMotorcycle, full size, sectioned, Yamaha XJ650 Seca Turbo, 5 speed, 653 cc engine, made by Yamaha Motor Corporation, Japan, 1982
Physical DescriptionMotorcycle, full size, sectioned, Yamaha XJ650 Seca Turbo, 5 speed, 653 cc engine, made by Yamaha Motor Corporation, Japan, 1982
The motor cycle features a 653 cc turbo-charged engine with a DOHC 4-stroke which developed 66.2 kW (88.7 hp) at 9000 rpm. It has air adjustable front forks, shaft drive, 5-speed transmission, electronic ignition and Yamaha Induction Control System (YICS). The turbo-charger is mounted unusually far from the exhaust ports, immediately behind and beneath the engine. The turbo blew air through the vented carburettors.
Fuel delivery was via an electric fuel pump and regulating valve. To enhance low speed operation a reed valve was used which drew air into the air filter instead of the turbo unit for when boost pressures were low. Once the boost was sufficiently high the valve closed and the engine could go into normal boost operation. An 'electronic ear' listened to detonation and where necessary retarded the timing until detonation ceased. A boost sensor advanced or retarded the timing depending on the level of boost in the intake manifold.
The motorcycle features an acrylic windscreen, twin mufflers, two pillion passenger grab rails, leg shields to protect against the wind and two small lockable storage units. (There was no under seat storage except for a standard issue took kit and a small security chain). The instruments are set in the fairing and include a boost gauge as well as a conventional tachometer and speedometer. There were also LCD warning lights to alert the rider of malfunctions including side-stand retraction, low fuel, oil, battery and brake fluid, as well as head and tail light failure. The fuel level gauge is a four section display.
The motorcycle is sectioned to reveal its internal construction. It is finished in silver and black with a red stripe.
Model: XJ650 Turbo Seca
Years manufactured: 1983-1985
Engine type: air-cooled, 4-stroke, transverse four-cylinder, turbo-charged, DOHC, 2 valves per cylinder
Displacement: 653 cc
Bore and stroke: 63.0 x 52.4 mm
Compression ratio: 8.2 : 1
Maximum Power: (DIN) 66.2 kW at 9,000 rpm
Maximum torque: (DIN) 81.7 Nm at 7,000 -7,500 rpm
Lubrication: Wet sump
Carburettors: Mikuni BS30 (four)
Ignition: Transistor controlled
Starter system: Electric
Fuel tank capacity: 19 litres
Oil capacity: 3.5 litres
Transmission: 5 speed
Final transmission: Shaft device
Front suspension: Interconnected air-assisted forks
Rear suspension: Twin suspension struts
Front brakes: disc rotors with single piston callipers
Rear brakes: Drum
Overall Length: 2170 mm
Overall width: 730 mm
Overall height: 1355 mm
Seat height: 775 mm
Ground clearance: 135 mm
Dry weight: 230 kg
Front tyre: 3.25 V-19
Rear tyre: 120/90 V-18
Marks"Yamaha / Seca / Turbo"