🏷️ Basic Information

Make:

Yamaha

Model:

QT50

Model Nickname:

QT 50

Year:

1980

Engine Code:

N/A (Specific engine code not typically provided for this model, refer to manual for details)

Chassis Code:

N/A (Specific chassis code not typically provided for this model, refer to manual for details)

👋 Introduction

Segment:

Lightweight, urban commuter scooter popular in the late 1970s and early 1980s. Often used for short-distance travel and recreational purposes.

Competitors:

Competed with other small-displacement scooters from brands like Honda (e.g., Spree, Elite series), Suzuki, and Tomos during its production run.

Features:

Lightweight, fuel-efficient, simple operation, and distinctive styling for its era. Designed for ease of use and low running costs.

Audience:

Primarily aimed at younger riders, urban commuters, and those seeking an economical and easy-to-ride form of personal transportation.

📋 Manual Details

Coverage:

Comprehensive service and repair for the 1980 Yamaha QT50 QT 50.

Pages:

Estimated 150-250 pages (typical for a detailed service manual of this era; actual count not specified in product info).

Type:

Service Manual / Repair Manual.

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine:

Detailed disassembly, assembly, inspection, and adjustment of the engine components, including piston, cylinder, crankshaft, bearings, seals, and cooling system (air-cooled).

Fuel System:

Carburetor adjustment, cleaning, and rebuilding; fuel tank, fuel lines, and petcock servicing.

Ignition System:

Spark plug specifications, timing adjustment, magneto, CDI unit, and related electrical components.

Transmission:

Automatic transmission (CVT or similar system specific to QT50) inspection, lubrication, and component replacement; drive belt inspection and replacement.

Clutch:

Automatic clutch system inspection, maintenance, and servicing.

Suspension:

Front fork disassembly, oil change, seal replacement; rear shock absorber inspection and replacement.

Brakes:

Brake system diagnosis, adjustment, and component replacement (likely drum brakes front and rear); brake fluid specifications and bleeding procedures.

Electrical System:

Wiring diagrams, lighting system, horn, battery maintenance, charging system (alternator/generator), and troubleshooting of electrical faults.

Frame And Bodywork:

Disassembly and reassembly of body panels, seat, handlebars, fenders, and chassis components.

Wheels And Tires:

Tire pressure specifications, wheel bearing inspection and lubrication, tire replacement procedures.

Maintenance:

Routine maintenance tasks such as oil changes, filter replacements, spark plug checks, lubrication points, and general inspections.

Troubleshooting:

Systematic diagnostic procedures for common problems, including engine starting issues, poor performance, and electrical malfunctions.

Repair:

Step-by-step instructions for component disassembly, repair, reassembly, and adjustment for all major systems.

Overhaul:

Detailed procedures for complete engine and transmission overhauls.

Specifications:

Torque specifications for critical fasteners, clearance measurements, and component tolerances.

Wiring Diagrams:

Comprehensive electrical system wiring schematics.

Depth:

Targets professional technicians, implying detailed diagnostic procedures, specialized tool requirements, and in-depth repair techniques beyond basic owner's manual information.

📊 Manual Specifications

PDF Quality:

Assumed to be clear and legible for printing and on-screen viewing, though specific resolution is not stated.

Searchability:

PDF format typically allows for text searching of keywords, greatly enhancing usability.

Printable:

PDF format is inherently printable.

Binding:

N/A (Digital download - no physical binding).

Paper Type:

N/A (Digital download - no physical paper).

⚙️ Engine Specifications

Engine Type:

Two-stroke, air-cooled, single-cylinder.

Displacement:

49cc (Cubic Centimeters)

Bore X Stroke:

Refer to manual for specific dimensions (typical for this class around 39mm x 41.4mm, but requires confirmation).

Compression Ratio:

Refer to manual for specific ratio (typically around 6.5:1 to 7.5:1 for this era).

Horsepower:

Approximately 3.5 - 4.0 HP (Horsepower) at specific RPM, exact figure available in manual.

Torque:

Refer to manual for specific torque figures.

Top Speed:

Typically around 30-35 mph (miles per hour), dependent on rider weight and conditions.

Carburetor Model:

Likely a Mikuni VM series or similar, specific model number required from manual.

Fuel Type:

Unleaded gasoline, mixed with 2-stroke oil (ratio specified in manual, typically 50:1 or 100:1 depending on oil formulation).

Fuel Capacity:

Approx. 3-4 liters (0.8-1.0 gallons), exact figure from manual.

2 Stroke Oil Type:

High-quality 2-stroke oil, API TA or TC classification (refer to manual for precise specification).

🔧 Transmission

Transmission Type:

Automatic V-belt transmission (CVT) with automatic centrifugal clutch.

Optional Transmissions:

N/A (CVT was standard for this model).

Drive System:

Shaft drive or chain drive (QT50 typically uses a chain drive to the rear wheel, but manual will confirm).

Gear Ratios:

Variable, as it is a CVT system. Ratios are continuously variable within operating range.

Transmission Fluid:

Typically no separate transmission fluid; lubrication from engine oil and clutch mechanism. Refer to manual for specific recommendations.

📐 Dimensions

Overall Length:

Refer to manual for exact dimensions (typically around 1.6-1.7 meters).

Overall Width:

Refer to manual for exact dimensions (typically around 0.7 meters).

Overall Height:

Refer to manual for exact dimensions (typically around 1.0-1.1 meters).

Dry Weight:

Approximately 60-70 kg (130-155 lbs), actual spec in manual.

Curb Weight:

Refer to manual for exact curb weight.

Storage:

Typically includes under-seat storage and potentially a small front glove box or rack, depending on trim.

🛡️ Safety Features

Safety Standards:

Designed to comply with automotive safety standards of the era for light motorcycles/scooters.

Braking System:

Front and rear drum brakes for reliable stopping power. Manual details adjustment and maintenance.

Lighting:

Headlight, taillight, brake light, turn signals (where equipped), and instrument panel illumination.

Frame Construction:

Steel frame providing structural integrity.

Wheels Tires:

Typically 10-inch or 12-inch wheels with pneumatic tires for ride comfort and grip.

💡 Technology Features

Infotainment System:

N/A (No infotainment system present on this model).

Driver Assistance Features:

N/A (No electronic driver assistance features).

Connectivity Features:

N/A (No connectivity features).

Instrument Panel:

Basic analog gauges including speedometer, fuel level indicator (if equipped), and indicator lights for turn signals, high beam, etc. Manual details instrument functions and troubleshooting.

🔧 Maintenance

Oil Change Engine:

2-stroke, so no traditional engine oil change. Regular checks of 2-stroke oil reservoir level and addition as needed.

Spark Plug Replacement:

Recommended every 3,000-5,000 km (approx. 2,000-3,000 miles) or as per manual's specific recommendation. Check gap regularly.

Air Filter Cleaning:

Clean every 1,000-2,000 km (approx. 600-1,200 miles) and replace as needed. Manual will provide specific interval and cleaning method (e.g., washing with soap and water, or replacement).

Drive Belt Inspection:

Inspect every 4,000-6,000 km (approx. 2,500-3,700 miles) for wear, cracking, or stretching. Replace as needed.

Carburetor Cleaning:

As needed, typically every 5,000-10,000 km (approx. 3,000-6,000 miles) or when performance issues arise. Manual details process.

2 Stroke Oil:

Yamalube 2, or equivalent high-quality 2-stroke oil meeting JASO FB or FD standards. Mix ratio as specified in manual (e.g., 50:1 or 100:1).

Brake Fluid:

DOT 3 or DOT 4 brake fluid, depending on the system's specific requirements. Manual will state exact specification.

Carburetor Clogging:

Common with older, infrequent-use scooters due to fuel varnish. Regular use or periodic fuel stabilizer use can mitigate. Manual provides cleaning procedures.

Drive Belt Wear:

Belts can wear and stretch over time, affecting acceleration and top speed. Manual details inspection and replacement.

Ignition Coil Failure:

The CDI unit or ignition coil can fail, preventing spark. Manual assists in diagnosing ignition system faults.

Air Leaks Intake:

Leaky intake manifold (between carburetor and cylinder) can cause lean running and poor idle. Manual guides inspection and sealing.

📚 Vehicle History

Manufacturer:

Yamaha Motor Corporation, a renowned Japanese manufacturer known for motorcycles, musical instruments, and marine products.

Predecessors:

While not a direct lineage, Yamaha had a history of producing small-displacement, user-friendly scooters and mopeds.

Successors:

Yamaha continued to evolve its scooter lineup with models like the Jog and various Vino models, offering increasingly advanced features and engine technologies.

Production Years:

The QT50 was produced through the early 1980s, with the 1980 model year being a key example.

Manufacturing Location:

Likely manufactured in Japan, as is typical for Yamaha products of this era.

🏆 Awards & Recognition

Industry Awards:

N/A (Specific industry awards for this model are not widely documented, but it was a popular and well-regarded commuter scooter in its segment).

Consumer Ratings:

Generally positive for reliability and ease of use within its class and era, though specific formal ratings are rare for models of this vintage.

Emissions Certification:

Compliant with emissions standards applicable at the time of manufacture. Manual may provide emission control system details.