Start of Production

1978

Click to View Available Literature

End of Production

1985

Numbers Produced

28,158

Price

5,880 DM

Engine

 

Motor Type

Four-stroke two cylinder horizontally opposed "Boxer" engine, air cooled

Bore x Stroke

70 x 61.5 mm / 2.75 x 2.42 in

Displacement

473.4 cc

Max Power

35 hp (26 Kw) at 7,250 rpm or 27 hp (20 Kw) at 6,500 rpm

Max Torque

37.5 Nm at 5,500 rpm or 31.3 Nm at 5000 rpm

Compression Ratio

9.2 : 1 or 8.2 : 1

Valves Per Cylinder

2

Valve Control

OHV, using push rod and rocker arm

Carburation System

2 constant depression carburettors, Bing 64/28/303 -  64/28/304 or 64/26/303 - 64/326304

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: 3.89 or 1 : 4.25

Bevel/Crownwheel

9 / 35 teeth or 8 / 34 teeth



Electrical System

 

Ignition System

Battery ignition. From 1981model: Contact free electronic ignition

Alternator

Bosch 280 W

Starter

Bosch 0.7 Kw

Spark Plugs

Bosch W 5 D / Beru 14-5D / Champion N 6 Y or Bosch W 7 D / Beru 14-7D / Champion N 10 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

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. 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 1080 mm (83.07 x 27.08 x 42.51 in)

Wheel Base

1390 mm / 54.72 in to 1980.  1981 on1400 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

5.5 litres/ or 5.0 litres per 100 Km (at constant 90 Kph) /51 mpg / 42 mpg US or 56 mpg / 47 mpg US

Top Speed

160 Kph 100 mph or 145 Kph / 90 mph

Acceleration 0 - 100 Kph / 62 mph

7.4 seconds or 8.5 seconds



Information kindly supplied by P.Hawksley

www.bmbikes.co.uk