🏷️ Basic Information

Make:

Yamaha

Model:

XS650G / XS650SG

Year:

1980

👋 Introduction

Positioning:

The Yamaha XS650 line, including the 1980 G and SG models, represented Yamaha's entry into the larger displacement motorcycle market, aiming to compete with established British twins and American cruisers with a more modern, reliable, and Japanese-engineered parallel-twin engine.

Competitors:

Competed with models like the Triumph Bonneville, BSA models, Harley-Davidson Sportster, and Moto Guzzi V7/V1000 during its production run. The XS650 was often praised for its smoother operation and electrical reliability compared to many European contemporaries.

Engine Architecture:

A distinctive 654cc, air-cooled, SOHC parallel-twin engine with a 277-degree crankshaft, which mimicked the firing interval and exhaust note of a traditional British vertical twin, a deliberate design choice by Yamaha.

Handling Characteristics:

Known for its relatively compliant suspension and stable handling, making it a comfortable cruiser and capable touring machine for its era.

Design Evolution:

The 'G' and 'SG' represented updates to the XS650 line, likely including minor styling revisions, improved electrical components, or chassis refinements over earlier models.

📋 Manual Details

Manual Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

Page Count:

212

📖 Manual Coverage

Engine:

Complete engine overhaul, disassembly, assembly, inspection, and adjustment of all internal components (pistons, rings, connecting rods, crankshaft, valves, camshafts).

Fuel System:

Carburetor identification, disassembly, cleaning, adjustment, troubleshooting, and fuel tank and petcock servicing.

Ignition System:

CDI ignition system, spark plugs, coils, timing, and troubleshooting procedures.

Transmission:

Gearbox disassembly, inspection, reassembly, clutch operation, and maintenance.

Electrical System:

Wiring diagrams, battery, charging system (alternator, rectifier/regulator), lighting, starter motor, and electronic component testing.

Chassis:

Frame inspection, steering head bearings, fork servicing, rear shock absorber replacement, and wheel bearing maintenance.

Brakes:

Front and rear brake system overhaul, including caliper, master cylinder, brake pads/shoes, lines, and fluid replacement.

Bodywork:

Fairing and body panel removal/installation, seat servicing, fuel tank mounting, and minor cosmetic repairs.

Routine Maintenance:

Oil changes, filter replacement, chain adjustment, lubrication points, tire pressure checks, and general inspection.

Troubleshooting:

Diagnostic charts and procedures for common operational problems across all major systems.

Repair Overhaul:

Detailed step-by-step instructions for component removal, repair, and reinstallation.

Adjustment:

Specific procedures for adjusting carburetors, ignition timing, valve clearances, and clutch/throttle cables.

Specifications Data:

Torque values, clearances, fluid capacities, and other critical technical data for accurate servicing.

Depth:

Comprehensive, covering basic maintenance to complete engine and component rebuilds, suitable for experienced technicians and advanced hobbyists.

📊 Manual Specifications

File Format:

PDF

Searchable:

Likely (depending on original scan quality), enabling quick access to specific information.

Printable:

Yes, allowing users to print specific sections or the entire manual.

Quality:

Varies based on original source, but typically clear line drawings and text for technical manuals.

Binding:

N/A (Digital PDF format)

Paper Type:

N/A (Digital PDF format)

⚙️ Engine Specifications

Engine Type:

Four-stroke, air-cooled, SOHC, parallel-twin

Displacement:

654 cc (39.9 cubic inches)

Bore X Stroke:

75.0 mm x 74.0 mm

Compression Ratio:

8.4:1 (typical for this era)

Crankshaft Configuration:

277-degree firing interval

Horsepower:

Approx. 45-50 HP (at the crankshaft, depending on tuning and specific model variant)

Torque:

Approx. 38-40 lb-ft (at the crankshaft, depending on tuning and specific model variant)

Carburetors:

Dual Mikuni VM34SC constant-velocity carburetors

Fuel Capacity:

Approx. 3.7 US gallons (14 liters)

Oil Capacity:

Approx. 2.5 US quarts (2.4 liters) with filter change

Oil Type:

Typically SAE 10W-40 or 20W-50 motorcycle specific oil (refer to manual for precise specifications).

🔧 Transmission

Type:

5-speed constant mesh

Options:

N/A (Standard 5-speed gearbox)

Drive Type:

Chain drive

Clutch Type:

Wet, multi-plate

📐 Dimensions

Length:

Approx. 86.6 inches (2199 mm) - varies slightly by model configuration

Width:

Approx. 31.9 inches (810 mm) - varies slightly by model configuration

Height:

Approx. 47.6 inches (1209 mm) - varies slightly by model configuration

Wheelbase:

Approx. 58.1 inches (1475 mm)

Dry Weight:

Approx. 430 lbs (195 kg)

Wet Weight:

Approx. 459 lbs (208 kg) - with all fluids

Front Tire Size:

3.50-19 (typical)

Rear Tire Size:

4.00-18 (typical)

Wheel Type:

Spoked wheels

Bolt Pattern:

N/A (hub-based spoke wheels)

🛡️ Safety Features

Safety Standards:

Motorcycles of this era were subject to national safety regulations for lighting, braking, and emissions, but lacked formal crash test ratings like modern cars. The manual covers safe operation and maintenance procedures.

Braking System:

Front: Single disc brake with hydraulic caliper. Rear: Drum brake.

Lighting:

Headlight, taillight, brake light, turn signals (front and rear), and dashboard illumination.

💡 Technology Features

Infotainment System:

N/A (This is a 1980s motorcycle, no electronic infotainment system).

Assistance Features:

N/A (No electronic driver assistance features on this model).

Connectivity Features:

N/A (No electronic connectivity features on this model).

Ignition Type:

Transistor Controlled Ignition (TCI) / Capacitor Discharge Ignition (CDI) system, offering improved reliability and tuneability over older points-based systems.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000 miles (4,800 km) or 6 months, whichever comes first (refer to manual for exact recommendation).

Valve Clearance Check:

Recommended every 6,000 miles (9,600 km) or annually.

Spark Plug Replacement:

Recommended every 6,000 miles (9,600 km).

Chain Lubrication:

Every 500 miles (800 km) or after riding in rain.

Brake Fluid:

DOT 3 or DOT 4 brake fluid (check manual for specific Yamaha recommendation).

Transmission Oil:

Separate transmission oil is not typically used; the engine oil lubricates the gearbox and clutch. Refer to engine oil specifications.

Charging System:

Early models sometimes suffered from rectifier/regulator failures, leading to charging issues. Manual provides diagnostic procedures.

Carburetor Sync:

Carburetors can drift out of sync, causing rough running. The manual details the sync procedure.

Cam Chain Tensioner:

The cam chain tensioner can wear over time, leading to rattling noises. The manual provides guidance on inspection and replacement.

Fork Seals:

Fork seal replacement is a common maintenance item due to age and mileage. The manual details the fork disassembly and seal replacement process.

📚 Vehicle History

Yamaha Motorcycles:

Yamaha Motor Company, founded in 1955, quickly established a reputation for quality, innovation, and performance in the motorcycle industry, building on its origins in musical instrument manufacturing.

Xs650 Lineage:

The XS650 was first introduced in 1970 and underwent continuous development and styling updates through the late 1970s and into the 1980s. The G and SG models are part of this later evolution, with the SG typically representing a sportier variant or specific market configuration.

Production Period:

The XS650 series was produced from 1970 to 1985. The 1980 models are mid-cycle iterations within this successful production run.

Manufacturing Location:

Primarily manufactured in Japan.

🏆 Awards & Recognition

Industry Impact:

The XS650 line was widely recognized for bringing Japanese reliability and refinement to the larger displacement motorcycle segment, influencing subsequent motorcycle designs and establishing Yamaha as a major global player.

Motorcycle Reviews:

Contemporary reviews often praised its smooth engine operation, solid build quality, and balanced handling, though some noted a lack of outright power compared to larger-displacement European or American twins.

Automotive Standards:

Manufactured to meet Japanese domestic market and international safety and emissions standards applicable at the time of production.