CT-90 and CT-110 Specifications
This is a partly-incomplete list of specifications for the typical CT-90 and typical CT-110. Many of these specs changed slightly across the production years, so if you're doing something that depends heavily on a particular year's specs, check the factory service manuals or check with a Honda dealer. Click here to skip down to CT-110 specs. If you can clarify, correct or add to any of these specs, please email us and we'll update the list. Let us know where you got your information.

CT90

Features:
89cc single-cylinder, SOHC hemi-head engine
4-speed synchro gearbox with automatic clutch and 1:2 ratio Posi-Torque subtransmission (later CT-90 after mid-1969)
Swing arm rear suspension, dual rear shocks
Telescoping-shock front forks (except early CT-90, with trailing-link front suspension)
Drum brakes front & rear

Specs:
71" long, 26" wide, 39" high
Wheelbase: 47" (1188mm)
Ground clearance: 5.4"
Weight: 179 pounds dry
Top speed: 56 mph (rated)
Gas mileage: 175 mpg (rated) at 25 mph
Hill climb: 18 degrees stock, 25 degrees Posi-Torque engaged (rated)

Engine:
Bore/stroke: 50x45.6mm
Displacement: 89.6cc
Compression: 8.2:1
Cylinder compression: 170 psi
Power: 7.0 @ 8500rpm
Torque: 5 lb/ft @6000 rpm
Weight: 55 lbs dry
Keihin carburetor with high-altitude compensator (many models)

Capacities:
Fuel: 1.6 gallons
Oil: 1.9 pints
Optional spare gas tank: approx 4 pts.
Spark plug: NGK D8-HS (rated) or D8-HA
Tires: 2.75-17 4-ply rated (originally Yokohama)

Gear ratios:
Primary driven gear reduction: 3.722:1
1st gear: 2.538:1
2nd gear: 1.611:1
3rd gear: 1.190:1
4th gear: 0.958:1
Posi-Torque subtransmission: 2:1 (approx.)

Note: prior to serial number 122550, final drive reduction was accomplished by a double-size concentric rear sprocket, and by adding in an extra segment of drive chain. After this (1969) the 2:1 step-down transmission was added.

CT-110

Features:
105cc single-cylinder, SOHC hemi-head engine
4-speed synchro gearbox with automatic clutch and 1:2 ratio Posi-Torque subtransmission (except 1980 model)
Swing arm rear suspension, dual rear shocks
Telescoping-shock front forks
Drum brakes front & rear
Electronic CDI ignition (1985-1986)

Specs:
xx" long, xx" wide, xx" high
Wheelbase: xx"
Ground clearance: xx"
Weight: 197 lb. dry
Top speed: 56 mph (rated)
Gas mileage: 175 mpg (rated) at 25 mph
Hill climb: 18 degrees stock, 25 degrees Posi-Torque engaged (rated)

Engine:

Bore/stroke: 53mmx49.5mm
Displacement: 105cc
Compression: 8.5:1
Cylinder compression: 140-165PSI
Power: 7.5hp @7500rpm
Torque:
Weight:
Keihin carburetor

Capacities:
Fuel: 1.6 gallons
Optional spare gas tank: approx 4 pts.
Oil: 2.0 pints
Spark plug: NGK D8-EA
Tires: 2.75-17 4-ply rated (originally Yokohama)
Battery: type 6N4-2A-8

Gear ratios:
Primary driven gear reduction: 3.722:1
1st gear: 2.538:1
2nd gear: 1.611:1
3rd gear: 1.190:1
4th gear: 0.958:1
Posi-Torque subtransmission: 2:1 (approx., except 1980 model)

Sprockets: 15T/45T, 3:1 stepdown

Note: for some reason, the 1980 models lacked the step-down 2:1 reduction subtransmission.

Last updated: 03/03/2002