This manual provides comprehensive workshop repair and service information for the ST50, ST70, CT70, and CT70H models, covering production years from 1969 through 1982. These iconic small displacement motorcycles are celebrated for their robust engineering, reliability, and versatility, bridging the gap between minibikes and full-sized motorcycles. The ST and CT series are noted for their user-friendly operation, with various transmission options including semi-automatic and manual clutches, making them accessible to a wide range of riders. Their enduring appeal lies in their simplicity, durability, and the foundational role they played in the legacy of quality small motorcycles. This workshop service repair manual is meticulously designed to empower owners and mechanics with the knowledge needed for thorough maintenance and repair. It covers a wide array of critical systems, including detailed engine overhaul procedures, fuel and transmission system servicing, electrical diagnostics, and frame and suspension maintenance. The manual offers systematic troubleshooting guides, precise technical specifications such as torque values and clearances, and clear explanations of routine maintenance tasks. With specific attention to model variations and year-specific addenda, this resource ensures users can effectively restore and maintain these classic motorcycles, covering everything from basic upkeep to complex component repair. 🏷️ Basic Information Identification Make: Honda Model: ST50 / ST70 / CT70 / CT70H Product Name: 1969-1982 Honda ST50-70 CT70-70H Service Repair Manual PDF Download Generation Covered Years: 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982 Codes Model Codes: ST50, ST70, CT70, CT70H 👋 Introduction Market Position Target Audience: Owners and mechanics seeking detailed information for maintaining and repairing vintage Honda ST/CT series motorcycles Competitive Analysis Value Proposition: Provides essential technical data and procedures to restore and maintain these iconic small motorcycles, saving on professional repair costs Key Features Uniqueness: Specific coverage for multiple model years and variants, including important addenda for later models Utility: Empowers users with the knowledge to perform a wide range of maintenance and repair tasks 📋 Manual Details Coverage Areas Manual Coverage Scope: Comprehensive workshop repair and service information Page Count Estimated Page Count: Significant; exact count not provided but implied to be extensive covering multiple model variants and years Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Overhaul: Complete engine disassembly, inspection, repair, and reassembly Fuel System Maintenance: Carburetor adjustment and cleaning, fuel tank and line service Transmission Service: Clutch, gearbox, and final drive unit maintenance and repair Electrical Diagnostics: Ignition system, lighting, charging system, and wiring harness troubleshooting Frame And Suspension: Frame inspection, steering, front forks, and rear suspension maintenance Braking System: Brake lever, cable, and drum brake servicing Wheel And Tire: Wheel bearing service, spoke tensioning, tire replacement Procedures Included Routine Maintenance: Oil changes, filter replacement, chain adjustment, lubrication points Troubleshooting Guides: Systematic diagnostic procedures for common problems Engine Rebuild: Piston, cylinder, crankshaft, and valve servicing procedures Electrical Component Testing: Coil, spark plug, battery, and lighting circuit testing Wiring Diagram Interpretation: Detailed schematics for troubleshooting and repair Addendum Updates: Specific repair and adjustment information for various model year addendums (K4, K6, K7, Z, A, B, C) Technical Depth Diagnostic Capabilities: Advanced diagnostic information, including troubleshooting charts and expected values Repair Complexity: Suitable for both intermediate DIY enthusiasts and professional mechanics Specifications Detail: Precise torque values, clearances, and adjustment specifications 📊 Manual Specifications File Format File Type: PDF Compatibility: All Versions of Windows & Mac Print Quality Readability: High-quality scans ensuring clear text and legible diagrams Binding Type Delivery Method: Digital Download (Not a physical book) Paper Type Digital Format Details: Searchable text and image quality suitable for on-screen viewing and selective printing ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, four-stroke, SOHC (Single Overhead Camshaft) Displacement St50: 49cc Displacement St70: 69cc Displacement Ct70: 72cc (later models may vary slightly, typically 71.7cc) Performance Bore X Stroke St50: 39.0 mm x 41.4 mm Bore X Stroke Ct70: 47.0 mm x 41.4 mm Compression Ratio: Approximately 8.4:1 to 9.5:1 depending on model and year Horsepower St50: Approx. 4.5 - 5.0 HP @ 9,000 RPM Horsepower Ct70: Approx. 6.0 - 7.0 HP @ 8,500 RPM Fuel System Carburetor Type: Keihin or similar Japanese carburetor, specific models vary by year and displacement (e.g., PB6 / PB7) Fuel Type: Unleaded gasoline (octane rating typically 86 or higher) Fluid Specifications Engine Oil Type: SAE 10W-30 API SE or SF classification recommended Engine Oil Capacity: Approximately 0.8 - 1.0 Liters (refer to specific model chapter for exact quantity) 🔧 Transmission Standard Ct70 Standard Transmission: 3-speed semi-automatic (automatic clutch with foot shifter) Ct70H Standard Transmission: 4-speed manual transmission with manual clutch (lever operated) St50/St70 Transmission: Typically 2-speed or 3-speed automatic/semi-automatic (specifics vary) Optional Transmission Options: CT70H offered a manual clutch and 4-speed transmission as a distinct model from the semi-automatic CT70. Features Clutch Type: Wet multi-plate type for...