🏷️ Basic Information Identification Make: Yamaha Model: QT50 Model Designation: QT 50 Model Code: QT50 Generation Production Start Year: 1979 Production End Year: 1992 Codes Chassis Code Prefix: 2T0 👋 Introduction Market Position Segment: Lightweight Moped / Scooter Target Audience: Enthusiasts, owners, and mechanics requiring in-depth maintenance and repair information for the Yamaha QT50. Competitive Analysis Competitors: Honda Spree, Suzuki FA50, Tomos Revival, various other 50cc two-stroke mopeds of the era. Key Features Vehicle Type: Step-through moped with automatic transmission. Manual Value Proposition: Provides essential, factory-level repair and maintenance data for preserving the longevity and performance of the Yamaha QT50. 📋 Manual Details Coverage Areas Covered Model Years: 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992 Page Count Estimated Pages: 300+ Manual Type Type: Workshop Service Manual / Repair Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine: Complete overhaul, tuning, diagnostics, carburetor, ignition system, cooling system, lubrication. Transmission: Automatic CVT (Torque Converter) system, belt replacement, clutch, gear oil. Chassis: Frame inspection, suspension (front fork, rear shock), steering system, wheel bearings. Brakes: Front drum brake, rear drum brake, brake cable adjustment and replacement, master cylinder (if applicable). Electrical: Wiring diagrams, lighting system, ignition coil, battery, charging system (stator, rectifier/regulator), switches, fuses. Fuel System: Fuel tank, fuel lines, fuel filter, carburetor (Mikuni VM series). Body And Frame: Body panels, seat, handlebars, fenders, fairings, decals, storage compartment. Procedures Included Maintenance: Routine checks, oil changes, spark plug replacement, air filter cleaning/replacement, chain adjustment (if applicable), brake adjustments, lubrication points. Repair: Engine rebuild, carburetor overhaul, transmission servicing, brake system repair, electrical component replacement, suspension overhaul. Troubleshooting: Diagnostic guides for common problems, symptom-based troubleshooting charts. Diagnostics: Engine performance issues, electrical system faults, starting problems. Technical Depth Depth: Comprehensive, covering everything from basic owner maintenance to full engine and transmission rebuilds, including detailed diagnostic procedures and specifications. 📊 Manual Specifications File Format Quality: High-resolution PDF, searchable text, clear diagrams and images. Print Quality Usability: Optimized for digital viewing and printing. Pages can be printed individually or as a complete manual. Binding Type Digital Format: N/A (Digital Download) Paper Type Digital Format: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Type: Two-stroke, single-cylinder, air-cooled Displacement: 49.2 cc Bore: 39.0 mm Stroke: 41.0 mm Compression Ratio: 7.2:1 Carburetor Model: Mikuni VM15SA Carburetor Specifications: Main Jet: #82.5, Pilot Jet: #17.5, Needle Jet: 6F52-3, Throttle Valve: #2.0, Air Screw: 1.5 Turns Out Performance Horsepower: Approx. 4.0 HP @ 6500 RPM (Varies slightly by year and market) Torque: Approx. 3.3 lb-ft @ 6000 RPM (Varies slightly by year and market) Fuel System Fuel Type: Unleaded gasoline Fuel Mixture: Pre-mix: 50:1 ratio (Gasoline to 2-stroke oil) Oil Type: Yamaha 2-stroke oil or equivalent API-TC rated oil 🔧 Transmission Standard Type: Automatic Continuously Variable Transmission (CVT) Drive Belt Part Number: 3X3-17641-00-00 Features Engagement Type: Centrifugal clutch with automatic variator. Gear Reduction: Reduction gear system for final drive. 📐 Dimensions Exterior Overall Length: Approx. 1650 mm (65 in) Overall Width: Approx. 660 mm (26 in) Overall Height: Approx. 980 mm (38.6 in) Wheelbase: Approx. 1140 mm (44.9 in) Ground Clearance: Approx. 100 mm (3.9 in) Weights Dry Weight: Approx. 65 kg (143 lbs) Wet Weight: Approx. 70 kg (154 lbs) (with fluids) Max Load Capacity: Approx. 90 kg (198 lbs) (rider and cargo) 🛡️ Safety Features Active Features Braking System: Front and rear drum brakes, operated by handlebar levers. Lighting: Headlight, taillight, brake light, turn signals (front and rear), instrument panel illumination. Passive Features Frame Construction: Steel frame providing a stable platform. Tires: Tubed tires, typically sized 2.50-10 or similar for both front and rear. 💡 Technology Features Infotainment Instrument Cluster: Analog speedometer, odometer, indicator lights for turn signals, high beam, and neutral (if applicable). Driver Assistance N A: No electronic driver assistance features. Connectivity N A: No connectivity features. 🔧 Maintenance Service Intervals Oil Change Frequency: 2-stroke oil reservoir refill as needed, based on oil level indicator. Spark Plug Replacement: Every 3,000 km (1,860 miles) or annually, check gap every 1,500 km (930 miles). Air Filter Cleaning: Every 1,000 km (620 miles) or annually. Replace as needed. Transmission Oil Change: Inspect and change every 6,000 km (3,700 miles) or every 2 years. Use Yamaha Gear Oil GL-4 80W-90. Cvt Belt Inspection: Inspect every 3,000 km (1,860 miles). Replace every 6,000 km (3,700 miles) or if signs of wear are present. Fluid Specifications Engine Oil: Yamaha 2-stroke engine oil (50:1 ratio premix) Gear Oil: Yamaha Gear Oil GL-4 80W-90 Known Issues Carburetor Clogging: Common with older two-stroke engines due to fuel varnish or debris. Requires regular cleaning. Cvt Belt Wear: Belts can stretch or fray over time, affecting acceleration and top speed. Regular inspection and replacement are crucial. Electrical Connections: Corrosion on connectors can lead to intermittent electrical faults. Cleaning and dielectric grease...