🏷️ Basic Information

Make:

Yamaha

Model:

QT50 QT 50

Year:

1988

Chassis Code:

Not specified in product information

Engine Code:

Not specified in product information

👋 Introduction

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.

📋 Manual Details

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)

📖 Manual Coverage

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.

📊 Manual 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 Specifications

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

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.

📐 Dimensions

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).

🛡️ Safety Features

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.

💡 Technology Features

Instrument Cluster:

Basic analog speedometer, odometer, and indicator lights (turn signals, high beam).

Safety Features:

Standard lighting and braking systems. No advanced electronic driver assistance systems.

Connectivity Options:

None.

🔧 Maintenance

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.

📚 Vehicle History

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.

🏆 Awards & Recognition

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.