Yamaha XS1100SF Special (1979)

The Yamaha XS1100SF Special is a four-stroke transverse four-cylinder motorcycle produced in 1979. It has a four-valve per cylinder and an air-cooled engine with a 1101cc capacity. The bike has a compression ratio of 9.2:1 and uses a 4x Mikuni BS 34SS Carburettor induction system.

The XS1100SF Special has a wet sump lubrication system, a TCI ignition, and uses a BP6ES (NGK) or N-8Y (Champion) spark plug. The motorcycle also features a GM 18Z-3A / 12v, 20 AH battery and an AC generator with a voltage regulator and rectifier.

The XS1100SF Special has a maximum power of 95 hp / 70.8 kW @ 8500 rpm and a max torque of 9.2 kgf-m / 66.5 lb-ft @ 6500 rpm. It uses a 5 speed transmission and a shaft final drive. The motorcycle also features telescopic fork front suspension and preload adjustable dual shocks swing arm rear suspension.

The XS1100SF Special has front and rear disc brakes with a wet weight of 258 kg / 568.7 lbs. It has a fuel capacity of 15 Litres / 3.9 US gal and consumes an average of 40.3 mpg. The motorcycle has a top speed of 126 mph / 202.8 km/h and can brake 100-0 in 39.7 m, completing a standing quarter-mile in 11.7 seconds at a speed of 114.2 mph / 183.8 km/h.

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Technical specifications:

Make Model: Yamaha XS 1100SF Special

Year: 1979

Engine: Four stroke transverse four cylinder, DOHC, 2 valves per cylinder.

Capacity: 1101 cc / 67.2 cu-in

Bore x Stroke: 71.5 x 68.6 mm

Cooling System: Air cooled

Compression Ratio: 9.2:1

Induction: 4x Mikuni BS 34SS Carburettor

Lubrication: Wet sump

Ignition: TCI additional vacuum adjusted! / electric kick starter – Witch is separated from the engine, for emergency mounting only

Spark Plug: BP6ES (NGK) or N-8Y (Champion)

Battery: GM 18Z-3A / 12v, 20 AH

Generator: A.C. Generator, voltage regulator, rectifier

Starting: Electric

Max Power: 95 hp / 70.8 kW @ 8500 rpm

Max Torque: 9.2 kgf-m / 66.5 lb-ft @ 6500 rpm

Clutch: Wet, multi-disc (8 drive plates, 7 driven plates)

Transmission: 5 Speed

Primary Reduction System: HY-VO chain & gear

Primary Reduction Ratio: 25/25 x 58/35 = 1.657

Final Drive: Shaft

Gear Ratio: 1st 38/17 (2.235) 2nd 39/24 (1.625) 3rd 36/28 (1.286) 4th 32/31 (1.032) 5th 30/34 (0.882)

Front Suspension: Telescopic fork.

Front Wheel Travel: 175 mm / 6.8 in

Rear Suspension: Dual shocks Swing arm, preload adjustable

Rear Wheel Travel: 80 mm / 3.1 in

Front Brakes: 2x 298mm discs

Rear Brakes: Single 298mm disc

Front Tyre: 3.50-19

Rear Tyre: 4.50-16

Rake: 29 o 30

Trail: 130 mm / 5.1 in

Wet Weight: 258 kg / 568.7 lbs

Fuel Capacity: 15 Litres / 3.9 US gal

Consumption Average: 40.3 mpg

Braking 100 – 0: 39.7 m

Standing 1/4 Mile: 11.7 sec / 114.2 mph 183.8 km/h

Top Speed: 126 mph / 202.8 km/h