Honda 90 Series S90, CL90, CD90, C90, CT90 Shop Manual, 1977–Onwards (P/N 6220003)

• Covers S90, CL90, CL90L, CD90, C90, and CT90 variants
• Official Honda Motor Co. publication (Ref: 6220003), printed in Japan, 1977
• 186 pages of technical specifications, engine assembly diagrams, and tuning data
• The definitive factory reference for mechanical architecture and maintenance specifications

Manual Contents

This 1977 shop manual provides the complete mechanical breakdown for the Honda 90 series. It covers the core components—from frame geometry to the engine and transmission systems—giving you the exact factory references needed for service work. Inside, you will find exploded diagrams, disassembly procedures, and wear limit inspections for the cylinder head, crankshaft, and gear assemblies. It also includes specific supplements for the CT90K2 through K8 and S90ZK1 models, detailing the Positorque transmission mechanism and various carburetor configurations used across the production run.

Technical Specifications & Data

The manual documents precise factory tolerances for all covered models. This includes standard valve clearances set at 0.05 mm and combustion chamber head volumes between 18–18.4 cc. Transmission data is segmented by model, outlining specifications like the 3.72 primary reduction ratio for most units. The electrical section details the 6V configuration with complete wiring schematics and ratings for the headlight, taillight, and turn signals. Cylinder head inspection charts list the hard wear limits for valve stems and springs to ensure components remain within factory spec. For a broader look at how factory workshop documentation is structured, this official Honda publication delivers the exact baseline data required for chassis, fuel, and engine reference.