These are the known mechanical and performance specifications for your 1978 Honda C90 K3.
Basic Specs
Engine
Displacement89.00 ccm (5.43 cubic inches)
Type
DetailsSingle cylinder, four-stroke
Max RPM10000
Compression8.2:1
Bore/Stroke50.0 x 45.6 mm (2.0 x 1.8 inches)
Valves/Cylinder2
FuelingCarburettor. keihin seiki
Ignitioncontact breaker points
Exhaustsinle stainless steel pipe
Lubricationwet sump
CoolingAir
Drivetrain
Gearbox3-speed
Final DriveChain
Clutchmulti plate wet automatic
Driveline
Performance
Horespower7.50 HP (5.5 kW)
Torque0.67 Nm (0.1 kgf-m or 0.5 ft.lbs)
Top Speed80.0 km/h (49.7 mph)
Fuel Economy & Polution
Fuel Consumption2.50 litres/100 km (40.0 km/l or 94.09 mpg)
Fuel Capacity5.50 litres (1.45 gallons)
Emissions58.0 CO2 g/km. (CO2 - Carbon dioxide emission)
Chassis
Frame Typepressed steel monoque with engine part of loadbearing
Rake27.0°
Trail75 mm (3.0 inches)
Front Suspensionhydraulically dampened leading link forks
Front Travel75 mm (3.0 inches)
Rear Suspensionhydraulically dampened with compression spring
Rear Travel100 mm (3.9 inches)
Seat
Seat Height790 mm (31.1 inches) If adjustable, lowest setting.
Alt. Seat Height
Total Height995 mm (39.2 inches)
Total Length1,830 mm (72.0 inches)
Total Width640 mm (25.2 inches)
Ground Clearance130 mm (5.1 inches)
Wheelbase1,190 mm (46.9 inches)
Dry Weight85.0 kg (187.4 pounds)
Wet Weight91.6 kg (201.9 pounds)
Wheels & Brakes
Front Tire/Tyre
Rear Tire/Tyre
Front BrakesExpanding brake (drum brake). twin expanding shoe
Front Brake Diameter110 mm (4.3 inches)
Rear BrakesExpanding brake (drum brake). twin expanding shoe
Rear Brake Diameter110 mm (4.3 inches)
Wheels
Comments
DURING 1978 HONDA WAS ALREADY LEGENDARY FOR THEIR STEP THRU SCOOTER BIKES. THE PERFORMANCE THEY ACHIEVED THROUGH TECHNICAL ADVANCMENTS FROM THEIR SMALL OVERHEAD CAMSHAFT MOTORS WAS INCREDIBLE. SIMILIAR MODELS ARE STILL AVALIABLE TODAY