🏷️ Basic Information Identification Make: Honda Model: ST50, CT70, CT70H Model Variant Codes: ST50, CT70, CT70H Generation Production Years Covered: 1969-1982 👋 Introduction Market Position Target Audience: Enthusiasts, DIY mechanics, and professional technicians working on vintage Honda ST50, CT70, and CT70H models. Key Features Professional Level Documentation: This manual is the same resource utilized by factory-trained technicians, ensuring accuracy and completeness. Diy Empowerment: Empowers owners to perform their own maintenance and repairs, saving money and enhancing vehicle longevity. Step By Step Instructions: Provides clear, sequential instructions for all repair and maintenance tasks. Competitive Analysis Value Proposition: Provides access to expert-level repair information, enabling owners to maintain and repair their classic Honda motorcycles effectively. 📋 Manual Details Coverage Areas Manual Type: Service and Repair Manual Language: English Format: PDF Download Model Coverage: Specifically covers Honda ST50, CT70, and CT70H models from 1969 to 1982. Page Count Page Count: 131 Content Density: High-density information packed into 131 pages, common for professional service manuals. File Format File Format: PDF Printable: Yes Compatibility: Windows/Mac Required Software: Adobe PDF Reader 📖 Manual Coverage Systems Covered Engine: Detailed coverage of engine disassembly, assembly, diagnosis, and repair. Fuel And Lubrication: Includes carburetor service, fuel tank, fuel lines, oil pump, and lubrication system. Electrical System: Covers ignition system, lighting, charging system, wiring diagrams, and component testing. Chassis: Includes frame, suspension (front and rear), steering, wheels, tires, and brakes. Suspension: Front telescopic forks and rear swingarm with dual shock absorbers, including adjustment and service. Steering: Handlebar, steering stem, bearings, and linkages. Procedures Included General Information: Provides an overview of the vehicle, safety precautions, and general maintenance principles. Periodic Maintenance: Detailed schedules and procedures for routine maintenance tasks. Tune Up: Step-by-step instructions for engine tune-up, including carburetor adjustment, ignition timing, and spark plug replacement. Servicing Information: Comprehensive repair and diagnostic procedures for all major vehicle systems. Troubleshooting: Detailed troubleshooting sections for common problems, guiding users through diagnostic steps. Specifications Data: Includes critical torque values, clearances, fluid capacities, and diagnostic specifications. Technical Depth Diagnostic Capabilities: Advanced troubleshooting guides and diagnostic procedures for identifying and resolving common and complex issues. Repair Scope: Covers everything from minor adjustments to complete engine rebuilds and major component overhauls. Wiring Diagrams: Includes comprehensive electrical wiring diagrams for accurate diagnosis and repair of the electrical system. ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, four-stroke, OHC single-cylinder (typical for these models). Displacement St50: 49cc (common for ST50 variations) Displacement Ct70: 72cc (common for CT70 variations) Engine Cooling: Forced air cooling. Performance Horsepower Range: Typically in the 4-7 hp range, depending on specific model and tuning. Torque Specs: Refer to manual for specific torque values for engine components. Fuel System Carburetor Type: Keihin carburetors (common models: PB16, PB18, etc., specific to engine size and year). Fuel Type: Unleaded gasoline. Fuel Delivery: Gravity feed from fuel tank to carburetor. Lubrication Oil Type: Honda Motorcycle Oil (e.g., 10W-30, 10W-40, refer to manual for exact specification). Oil Capacity: Refer to manual for specific oil capacity (typically around 0.7-0.9 liters). 🔧 Transmission Standard Transmission Type Ct70: 3-speed semi-automatic clutch (CT70). Transmission Type Ct70H: 4-speed manual clutch (CT70H). Transmission Type St50: Often equipped with an automatic centrifugal clutch or a 3-speed semi-automatic transmission, depending on the specific ST50 variant. Features Clutch Operation: Automatic centrifugal for some ST50 models, manual operation for CT70H, and semi-automatic for CT70. Gear Ratios: Detailed gear ratios for all models and transmissions provided within the manual. Final Drive: Chain drive. Fluid Type Transmission Fluid: Motorcycle engine oil is typically used in the transmission/crankcase of these models. Refer to manual for specific type and viscosity. 📐 Dimensions Exterior Wheelbase: Refer to manual for specific wheelbase dimensions for each model. Tire Size Front: Refer to manual for specific OE tire sizes (e.g., 2.50-10, 2.50-12, etc.). Tire Size Rear: Refer to manual for specific OE tire sizes (e.g., 2.50-10, 2.75-10, 3.00-10, etc.). Wheel Bolt Pattern: Not applicable; wheels are typically hub-mounted with brake drums. Weights Dry Weight: Typically in the range of 70-80 kg, depending on model and equipment. 🛡️ Safety Features Active Features Braking System Front: Drum brake. Braking System Rear: Drum brake. Passive Features Lighting System: Headlight, taillight, brake light, turn signals (depending on market regulations). 🔧 Maintenance Service Intervals Oil Change Interval: Typically every 1,000-2,000 km or 6-12 months, refer to manual for precise intervals. Spark Plug Replacement: Recommended at specified mileage intervals or as part of tune-up procedures. Valve Clearance Adjustment: Periodic adjustment is critical for engine performance and longevity; detailed procedures in the manual. Fluid Specifications Brake Fluid: Not applicable for drum brakes; refer to manual for any specific lubrication for brake components. Fork Oil Type: Refer to manual for recommended fork oil viscosity and type (e.g., SAE 10W). Known Issues Carburetor Clogging: Common issue with older carbureted vehicles due to fuel varnish; manual provides cleaning and...