🏷️ Basic Information

Make:

Triumph

Model:

650 Twin Series & Trident Triple Series

Engine Code General:

Triumph 650cc OHV Parallel-Twin, Triumph 750cc OHV Parallel-Triple (for Trident models)

👋 Introduction

Market Position:

Essential resource for owners and restorers of classic British parallel-twin and triple-cylinder motorcycles, a significant segment of the vintage motorcycle market.

Competitive Analysis:

Directly targets owners of Triumph 650cc models and related bikes, offering a consolidated and comprehensive repair solution that may surpass fragmented factory documentation for older models.

Key Features:

Broad model coverage within a single manual, detailed technical procedures, troubleshooting guidance, and diagrams crucial for maintaining and repairing these iconic motorcycles.

📋 Manual Details

Models Covered Summary:

All older Triumph 650cc parallel-twin motorcycles, including variations and derivatives. Also covers Triumph 250cc, 500cc parallel-twin models, and the Triumph 750cc Trident triple-cylinder models.

Page Count:

76

Manual Type:

Service and Repair Manual

Language:

English

Format:

Digital Download (implied PDF or similar for instant download)

📖 Manual Coverage

Engine Systems:

Engine overhaul, tuning, carburetion (e.g., Amal Concentric, Monobloc), ignition systems (points, coil), lubrication, cooling (air-cooled), valve train, piston and cylinder assembly, crankshaft and connecting rods, gearbox integration.

Transmission Systems:

Gearbox dismantling and reassembly, clutch operation and adjustment, gear selection mechanisms, primary drive system (chain/gear), final drive (chain).

Chassis And Suspension:

Frame inspection and repair, front fork (telescopic) service, rear suspension (swingarm, shocks) maintenance, wheel bearing replacement, steering head bearing adjustment.

Braking Systems:

Drum brake service and adjustment (front and rear), hydraulic disc brake systems (where applicable, depending on model year/variant), brake cable routing and adjustment.

Electrical Systems:

Wiring diagrams, lighting circuits, charging system (alternator/dynamo), ignition coil and spark plug system, battery maintenance, horn, indicators.

Maintenance Procedures:

Routine servicing, oil changes, filter replacement, chain adjustment, brake adjustments, spark plug replacement, carburation cleaning and tuning, lubrication points.

Repair Procedures:

Engine rebuilds, gearbox repairs, suspension overhaul, electrical fault finding and repair, component replacement (e.g., pistons, valves, bearings), fuel system repair.

Troubleshooting Guides:

Diagnostic steps for common running issues, electrical faults, starting problems, braking performance issues, and handling characteristics.

Technical Depth:

Comprehensive; covers routine maintenance, adjustments, diagnostics, troubleshooting, and full engine and gearbox rebuilds. Suitable for both amateur mechanics and professional workshops.

📊 Manual Specifications

File Format:

PDF (likely, for instant digital download)

Print Quality:

Digital, with clear diagrams and text (based on preview availability).

Binding Type:

N/A (Digital)

Paper Type:

N/A (Digital)

⚙️ Engine Specifications

Engine Type 650:

Air-cooled, OHV, parallel-twin

Engine Displacement 650:

649 cc (39.6 cubic inches)

Bore X Stroke 650:

Approx. 71 mm x 82 mm (varies slightly by year/model)

Compression Ratio 650:

Typically 7.5:1 to 8.5:1 (varies by model and tuning)

Horsepower 650 Estimated:

Approx. 45-55 bhp (varies significantly by model, tuning, and year)

Torque 650 Estimated:

Approx. 40-45 lb-ft (varies significantly by model, tuning, and year)

Engine Type 750 Trident:

Air-cooled, OHV, parallel-triple

Engine Displacement 750 Trident:

740 cc (45.1 cubic inches)

Peak Rpm Estimated:

Around 6000-6500 RPM

Carburetor Types:

Amal Monobloc, Amal Concentric (most common), Dell'Orto (less common for stock).

Carburetor Size 650:

Typically 26-29mm twin carburetors (e.g., Amal 376/379 Concentric).

Fuel Type:

Leaded or unleaded gasoline with appropriate octane rating (manual will specify, often requiring additives for unleaded).

Ignition Type:

Contact breaker points, single coil or dual coil systems (depending on year/model).

Lubrication Type:

Wet sump (most 650 twins), some earlier models may have had pre-mix or separate oil systems for specific components.

🔧 Transmission

Transmission Type 650:

4-speed or 5-speed constant mesh, right-foot shift (pre-Unit construction). Later models might have left-foot shift.

Transmission Type 750 Trident:

5-speed constant mesh, left-foot shift.

Clutch Type:

Wet multi-plate clutch, operated by cable.

Primary Drive:

Chain drive (from engine crankshaft to gearbox input shaft).

Final Drive:

Chain drive (from gearbox output shaft to rear wheel sprocket).

Gearbox Oil Specification:

Typically SAE 20W/50 or SAE 30 monograde oil (specific recommendations in manual).

📐 Dimensions

Wheelbase Approx:

Approx. 56-58 inches (1420-1470 mm) for 650 twins, longer for Trident.

Dry Weight Approx 650:

Approx. 370-420 lbs (168-190 kg) for 650 twins, depending on model.

Fuel Capacity Approx 650:

Approx. 3.5-4.0 US gallons (13-15 liters).

🛡️ Safety Features

Safety Ratings:

N/A for this era of motorcycle; safety focus is on proper maintenance and rider skill.

Active Safety Features:

Effective braking systems (drum/disc), stable chassis geometry, proper tire inflation, lighting for visibility.

Passive Safety Features:

Frame integrity, rider protection through proper maintenance of all components.

💡 Technology Features

Infotainment Features:

N/A (Classic motorcycle era)

Driver Assistance Features:

N/A (Classic motorcycle era)

Connectivity Features:

N/A (Classic motorcycle era)

🔧 Maintenance

Oil Change Interval:

Typically every 2,000-3,000 miles (3,000-5,000 km) or annually, whichever comes first (manual will provide precise figures).

Chain Lubrication Interval:

Every 500-1000 miles (800-1600 km) and after washing or riding in rain.

Valve Adjustment Interval:

Every 5,000-6,000 miles (8,000-10,000 km) or as recommended by manual for optimal performance.

Engine Oil Grade:

SAE 20W/50 or SAE 30 (verify specific recommendation in manual, often a monograde oil is preferred for older engines).

Engine Oil Capacity:

Approx. 4 US pints (1.9 Liters) for 650 twins (verify in manual).

Fork Oil Specification:

SAE 10W or SAE 20W fork oil (specific type and quantity critical, as detailed in manual).

Known Issues General:

Oil leaks (especially from crankcase seals, rocker boxes), gearbox oil consumption, clutch drag, vibration at certain RPMs, ignition timing accuracy, carburation tuning sensitivity.

Known Issues Engine 650:

Valve guide wear, worn timing bushes, oil pump wear, main bearing wear (can lead to rod knock).

Known Issues Electrical:

Aging wiring looms, weak charging systems (especially dynamo-equipped models), Lucas 'Prince of Darkness' reputation for electrical reliability.

Common Upgrades Mentioned:

Electronic ignition conversions, upgraded charging systems, modern carburetor conversions, braided brake lines.

📚 Vehicle History

Brand Heritage:

Triumph Motorcycles Ltd. is one of the oldest motorcycle manufacturers, renowned for its British engineering, iconic parallel-twin engines, and contributions to motorcycle sport and culture.

Model Evolution 650:

The 650cc parallel-twin engine was a direct evolution from Triumph's pre-war parallel-twin designs and became a dominant force in the 1950s and 60s, powering models like the Bonneville, Tiger, and Trophy. It was known for its performance and distinctive sound.

Model Evolution Trident:

The Trident was Triumph's answer to the growing demand for multi-cylinder engines, featuring a 750cc three-cylinder layout that offered increased smoothness and power, establishing its own racing heritage and distinct identity.

Production Period 650:

The 650cc parallel-twin engine was primarily produced from the early 1950s through the mid-1970s, with various updates and designations.

Production Period Trident:

The Triumph Trident 750 was produced from the late 1960s through the 1970s.

🏆 Awards & Recognition

Recognitions:

Triumph 650 models (especially Bonneville) are recognized as iconic cultural symbols and highly sought-after classics. The Triumph racing heritage, including successes with models derived from these engines, is widely celebrated.