Engine
Motor Type
Four-stroke two cylinder horizontally opposed “Boxer” engine, air cooled
Bore x Stroke
82 x 61.5 mm (3.22 x 2.42 in)
Displacement
649.6 cc
Max Power
45 hp (33 Kw) at 7,250 rpm. From 1981 50 hp 37 Kw at 7,250
Max Torque
Compression Ratio
9.2 : 1
Valves Per Cylinder
2
Valve Control
OHV, using push rod and rocker arm
Carburation System
2 constant depression carburettors, Bing 64/32/2030 – 64/32/2040 or 64/32/307 – 64/32/308
Engine Lubricating System
Wet sump
Power Transmission
Clutch
Dry single plate, with diaphragm spring
Number of Gears
5
Gear Selection
Dog type gearbox (ratchet foot lever)
Gearbox Ratios
4.4 / 2.86 / 2.07 / 1.67 / 1.50 : 1
Rear Wheel Ratio
1: 3.44
Bevel/Crownwheel
9 / 31 teeth
Electrical System
Ignition System
Battery ignition. From 1981 model: Contact free electronic ignition
Alternator
Bosch 280 W
Starter
Bosch 0.7 hp
Spark Plugs
Bosch W 5 D / Beru 14-5D / Champion N 6 Y
Chassis
Type of Frame
Double loop tubular frame with bolt on rear section
Front wheel suspension
Telescopic fork with hydraulic shock absorber
Rear wheel suspension
Long swinging arm with adjustable strut
Spring Travel Front/Rear
175 / 110 mm (6.88 / 4.33 in)
Wheel Rims, Front
1.85 B 18
Wheel Rims, Rear
2.50 B 18
Tyres, Front
3.25 S 18
Tyres, Rear
4.00 S 18
Brakes, Front
Single disc brake 260 mm / 10.23 in diameter. Twin disc on later models. ATE 2 piston caliper to 1979. 1979 on models Brembo 2 piston caliper
Brakes, Rear
Simplex drum brake 200 mm / 7.87 in diameter
Dimensions/Weights
Length x Width x Height
2110 x 688 x 1090 mm (83.07 x 27.08 x 42.91 in)
Wheel Base
1390 mm / 54.72 in to 1980. 1400 mm / 55.11 in
Fuel Tank Capacity
22 litres / 4.83 gal / 5.81 gal US
Unladen Weight with Full Tank
205 Kg / 451 lb
Max. Permissible Weight
398 Kg / 876 lb
Ground Clearance
130 mm / 5.11 in
Seat Height (Unladen) Up to 1980
770 mm (30.3 inches)
Seat Height (Unladen) 1981 On
810 mm (31.9 inches)
Fuel Consumption
4.6 litres 100 Km (at constant 90 Kph) / 61 mpg / 51 mpg US
Top Speed
175 Kph / 108 mph
Acceleration 0 – 100 Kph / 62 mph
5.9 seconds (1981 model on: 5.8 seconds)
