Yamaha TX650 III (1977-79)

The Yamaha TX650 III motorcycle was produced from 1977 to 1979 and featured a four-stroke, parallel twin cylinder engine with a capacity of 653cc. The engine had a compression ratio of 8.4:1 and was cooled by air with lubrication from a wet sump. Induction was accomplished via two Mikuni carburetors, and ignition was provided by a battery and induction coil. The bike had a maximum power output of 39.5 kW/53 hp at 7200 rpm and a maximum torque of 54 Nm/5.5 kgf-m/39.8 lb-ft at 6800 rpm. The transmission featured five speeds, and the final drive was via chain. The front suspension was telescopic forks, and the rear suspension had dual shock absorbers. The front brakes consisted of twin hydraulic discs, while the rear brakes were drums. The bike had a maximum speed of 185 km/h or 115 mph. The dimensions of the bike were 2175 mm in length, 780 mm in width, and 1090 mm in height. The wheelbase was 1435 mm, the ground clearance was 150 mm, and the seat height was 810 mm. The bike had a dry weight of 191 kg and a wet weight of 217 kg. The fuel capacity was 15 litres, and the oil capacity was 2.5 litres. The average fuel consumption was 5.0 L/100 km or 47 US mpg.

Technical specifications:

Make Model: Yamaha TX 650-II

Year: 1977 – 79
Engine: Four stroke, parallel twin cylinder, SOHC, 2 valves per cylinder.
Capacity: 653 cc / 39.8 cu in
Bore x Stroke: 75 x 74 mm
Compression Ratio: 8.4:1
Cooling System: Air cooled
Lubrication: Wet sump
Induction: 2 x Mikuni carburetors
Ignition: Battery, induction coil
Starting: Electric and kick
Max Power: 39.5 kW / 53 hp @ 7200 rpm
Max Torque: 54 Nm / 5.5 kgf-m / 39.8 lb-ft @ 6800 rpm
Transmission: 5 Speed
Final Drive: Chain
Front Suspension: Telescopic forks
Rear Suspension: Dual shock absorbers
Front Brakes: Twin hydraulic discs, 267 mm
Rear Brakes: Drum
Front Tyre: 3.50H-19 4PR
Rear Tyre: 4.00H-18 4PR
Dimensions: Length: 2175 mm / 85.6″Width: 780 mm / 30.7″Height: 1090 mm / 42.9″
Wheelbase: 1435 mm / 56.5″
Ground Clearance: 150 mm / 5.5″
Seat Height: 810 mm / 31.9″
Dry Weight: 191 kg / 420 lbs
Wet Weight: 217 kg / 478 lbs
Fuel Capacity: 15 Litres / 4.0 US gal
Average Consumption: 5.0 L/100 km / 20 km/l / 47 US mpg
Oil Capacity: 2.5 Litres / 2.6 US qts
Top Speed: 185 km/h / 115 mph