About the Honda CM400A
Service parts for the torque-converter CM400 Hondamatic.
Honda’s CM400A pairs a 395 cc air-cooled parallel twin with the Hondamatic transmission. A torque converter takes the place of the conventional manual-clutch arrangement, while the rider selects one of two forward ranges. That difference is central to choosing drivetrain parts even when some engine and brake components share other CM400 fitments.
Carburetors, airbox, engine covers and brakes
Routine work on the A can involve carburetor service, an air-filter change, engine-cover sealing or brake friction replacement. Identify the affected system first. A drive problem needs Hondamatic-specific diagnosis, not a manual-clutch shopping list borrowed from a C, E or T.
Model and application differencesCM400A Hondamatic transmission and service-year checks
Torque-converter transmission
Two selectable forward ranges distinguish the A from the manual-clutch CM400 models. Diagnose drive faults using Hondamatic-specific information.
Carburetor year coverage
The kit confirms 1980–1981 A applications. Confirm a 1979 carburetor separately rather than assuming the adjacent years fit.
Front disc and rear drum
Match the repair position. The front master-cylinder kit has a narrower year application than the front pads and rear shoes.
Frame and component identificationHonda CM400A frame numbers and identification
- Record the complete CM400 suffix, frame number, engine number and model year.
- Confirm the transmission type and the brake equipment actually fitted.
- Read the carburetor body identification before choosing a kit.
- Compare replacement forks, wheels or engines with the original model specification.
Selected factory starting-frame references only; these are not complete VINs or full production ranges. Match the model designation and entire frame stamping. No ending serial numbers are inferred. Shared numeric beginnings do not identify the transmission.
| Model year | Model | Beginning frame reference |
|---|---|---|
| 1979 | CM400A | 2000001 |
| 1980 | CM400A | 2100001 |
Contact PartsNMore with clear frame/VIN, engine and component photos. Include the original market and any known engine or front-end changes.