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B2524 Motorcycle, full size, sectioned, Yamaha XJ650 Seca Turbo, 5 speed, 653 cc engine, made by Yamaha Motor Corporation, Japan, 1982. Click to enlarge.

Sectioned Yamaha XJ650 Seca Turbo motorcycle

This Yamaha XJ650 Seca motorcycle is a special sectioned example of the first and only turbocharged road bike model made by Yamaha between 1982 and 1985. It was released in the same year as the supercharged Honda CX500 as both Japanese motorbike companies vied for increased sales. The Yamaha turbo engine was a basic XJ650 four-cylinder engine with strengthened pistons, bottom end, clutch and transmission.

In 1982 Peter Ballamy, from "Revs Motorcycle News", wrote after testing the motorcycle …


Object No.


Object Statement

Motorcycle, full size, sectioned, Yamaha XJ650 Seca Turbo, 5 speed, 653 cc engine, made by Yamaha Motor Corporation, Japan, 1982

Physical Description

Motorcycle, 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
Wheels: cast
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


"Yamaha / Seca / Turbo"



1400 mm


700 mm


2200 mm




Before it released the XJ650 Seca Turbo in 1982, Yamaha had gained previous experience building a five-litre, V8 twin-turbo race motor for Toyota in about 1977. Consequently, when Honda brought out their turbo-charge CX500 motorcycle early in 1982, Yamaha really had no choice but to quickly respond with a prototype, the XZ1100 Turbo, before production the XJ650 Turbo. Whereas Honda used a small engine with a high boost, Yamaha used a larger engine with only a mild boost (7 psi).

Unusually, Yamaha used carburettors in the XJ650's engine rather than fuel injection favoured by other Japanese manufacturers at the time. Yamaha claimed that the turbo unit was the world's smallest at the time. It was positioned away from the crankcase and below the swing arm pivot, which gave the motorcycle a lower centre of gravity. This position was also said to be part of its unconventional solution to the traditional problem of "turbo lag".

The Yamaha's top gear acceleration on a road test went from 5000 rpm (130 km/h) to 8000 rpm (190 km/h) while the ride position was semi-sporting. The tank and seat cowling were sculptured to provide a comfortable riding position as well as diverting wind around the rider's legs and knees. The fairings leading edge produced a stable pocket of air in front of the rider and the acrylic windscreen deflected wind over the rider's helmet.



This motorcycle was donated to the Museum by the Yamaha Division of McCulloch of Australia Pty Ltd of Seven Hills in Sydney in 1983.


Credit Line

Gift of McCulloch Of Aust Pty Ltd, 1983

Acquisition Date

11 July 1983

Cite this Object


Sectioned Yamaha XJ650 Seca Turbo motorcycle 2023, Museum of Applied Arts & Sciences, accessed 1 June 2023, <>


{{cite web |url= |title=Sectioned Yamaha XJ650 Seca Turbo motorcycle |author=Museum of Applied Arts & Sciences |access-date=1 June 2023 |publisher=Museum of Applied Arts & Sciences, Australia}}