Segment:
Lightweight scooter / moped segment
Target Audience:
Enthusiasts and owners seeking to maintain or restore their classic Yamaha QT50 moped.
Competitors:
Honda Spree, MB5, Aero 50; Tomos A3; Sachs MadAss; various other 50cc scooters and mopeds of the era.
Vehicle Appeal:
Simplicity, fuel efficiency, maneuverability, classic styling, and affordability.
Value Proposition:
Provides comprehensive technical data essential for preserving the functionality and longevity of a vintage Yamaha QT50.
Primary Coverage:
Full Service Repair and Maintenance
Secondary Coverage:
Rebuild, Refurbish, Restoration
Estimated Pages:
Detailed content suggests hundreds of pages, specific count not provided.
Type:
Service Manual / Repair Manual
Language:
English (presumed, based on typical market availability)
Format:
Digital (likely PDF, given product description context)
Engine:
Complete engine overhaul, tuning, troubleshooting, component analysis (carburetor, ignition, cooling, exhaust, etc.)
Transmission:
Clutch, gearbox, drive chain maintenance and repair (assuming CVT or similar for this model)
Brakes:
Front and rear brake system inspection, service, and repair (drum or disc, depending on specification)
Electrical:
Wiring diagrams, lighting, ignition system, battery, charging system, starter, troubleshooting electrical faults
Chassis:
Frame inspection, suspension components (forks, shocks), steering system, wheel bearings
Bodywork:
Fairing removal and installation, seat, fenders, fuel tank service
Maintenance:
Regular servicing, lubrication points, filter changes, spark plug replacement, valve adjustments (if applicable)
Repair:
Detailed step-by-step instructions for component replacement and repair
Troubleshooting:
Diagnostic charts and procedures for common and uncommon issues
Rebuild Refurbish:
Comprehensive instructions for complete teardown, cleaning, and reassembly of major components
Depth:
Comprehensive, covering everything from basic adjustments to complete engine and transmission rebuilds.
Diagnostics:
Includes diagnostic procedures, fault code interpretation (if applicable), and electrical system troubleshooting.
Specifications:
Detailed torque values, clearances, fluid capacities, and electrical resistance/voltage specifications.
File Type:
PDF (likely, digital format)
Searchability:
Likely searchable text for efficient information retrieval.
Printability:
Designed for clear printing of diagrams, charts, and text.
Binding:
N/A (Digital Format)
Paper Quality:
N/A (Digital Format)
Engine Type:
2-stroke, air-cooled, single-cylinder
Displacement:
49cc (2.99 cu in)
Bore X Stroke:
39.0 mm x 41.0 mm (1.54 in x 1.61 in)
Compression Ratio:
7.0:1 (typical for this era and type)
Horsepower:
Approx. 3.7 HP at 6,500 RPM (specifications may vary)
Torque:
Not readily available in product description, but estimated to be low-end focused for city use.
Carburetor:
Mikuni VM Series (likely VM16SH or similar, specific model in manual)
Fuel Type:
Unleaded gasoline, 87 octane (minimum), mixed with 2-stroke oil.
Fuel Oil Mix Ratio:
50:1 (typical for Yamaha 2-stroke engines of this era, manual will confirm exact ratio).
Ignition System:
CDI (Capacitor Discharge Ignition)
Cooling Method:
Forced Air Cooling
Transmission Type:
Automatic Continuously Variable Transmission (CVT)
Drive System:
Belt drive to rear wheel
Clutch Type:
Centrifugal automatic clutch
Gear Ratios:
Continuously variable via CVT mechanism; specific ratio ranges will be detailed in the manual.
Gear Oil Type:
Yamaha Gear Oil (or equivalent SAE 80W/90 hypoid gear oil). Manual will specify exact grade and quantity.
Overall Length:
Not specified in product information. Manual will contain this detail.
Overall Width:
Not specified in product information. Manual will contain this detail.
Overall Height:
Not specified in product information. Manual will contain this detail.
Dry Weight:
Approx. 72 kg (159 lbs). Manual will confirm exact figure.
Curb Weight:
Not specified in product information. Manual will contain this detail.
Storage Compartment:
Under-seat storage compartment (typical for scooters).
Crash Test Ratings:
N/A (Moped category typically does not undergo formal crash testing in the same manner as automobiles).
Lighting:
Headlight, taillight, brake light, turn signals (front and rear), license plate light.
Frame Structure:
Steel frame construction designed for stability and rider support.
Front Brake Type:
Drum brake (typical for this model year and class). Manual will confirm.
Rear Brake Type:
Drum brake (typical for this model year and class). Manual will confirm.
Oil Change Interval:
Transmission oil: Every 3,000 km (1,800 miles) or annually. Manual will provide precise intervals and oil type.
Spark Plug Replacement:
Recommended every 3,000-5,000 km (1,800-3,000 miles) or as per manual inspection. Manual will specify plug type and gap.
Air Filter Cleaning:
Regular inspection and cleaning/replacement as needed, typically every 1,500-3,000 km (900-1,800 miles). Manual will detail the procedure.
Transmission Fluid Type:
Yamaha Gear Oil or SAE 80W/90 hypoid gear oil. Manual will specify exact grade and capacity.
Coolant Type:
Air-cooled, no coolant required.
Brake Fluid Type:
If hydraulic disc brakes were ever introduced on variants, DOT 3 or 4 fluid would be typical. For drum brakes, no fluid is typically involved in the braking mechanism itself, only lubrication for cables.
Common Wear Items:
Carburetor gumming due to stale fuel, drive belt wear, aging electrical components, ignition coil failure, exhaust leaks.
Carburetor Cleaning:
Frequent issue on stored 2-stroke engines; requires thorough cleaning and potentially rebuilding.
Fuel Delivery:
Clogged fuel petcock or fuel lines can impede fuel flow.
Yamaha Motorcycles:
Yamaha has a long-standing reputation for producing reliable and performance-oriented motorcycles and scooters since its inception.
Qt50 Lineage:
The QT50 was part of Yamaha's entry-level scooter lineup, designed for urban mobility and ease of use, building upon previous scooter designs.
Production Years:
The QT50 was produced for several years, with the 1988 model being a specific iteration within its production run. (Exact start/end dates not in product info).
Manufacturing Location:
Likely manufactured in Japan or Southeast Asia by Yamaha Motor Corporation. Manual may provide specific country of origin.
Market Perception:
The QT50 is generally recognized as a simple, reliable, and fun-to-ride entry-level scooter, particularly popular among younger riders and commuters.
Reliability:
Yamaha's reputation suggests good inherent reliability when properly maintained, which this manual facilitates.
