Target Audience:
Owners and restorers of Triumph 650 twin motorcycles (6T Thunderbird, TR6 Trophy, T120 Bonneville) from engine number DU13375 onwards, mechanics, and parts suppliers.
Value Proposition:
Provides essential visual and numerical references for identifying correct replacement parts, crucial for maintaining the originality and functionality of classic Triumph motorcycles.
Illustrated Parts:
Fully illustrated with exploded views for clear identification of components and their relationships.
Disassembly Assembly Aid:
Designed to assist in the dismantling and reassembly process by clearly showing how parts fit together.
Part Number Reference:
Includes specific part numbers for ordering, crucial for sourcing the correct replacements.
Primary Focus:
Parts Identification and Listing
Estimated Pages:
Varies by edition, typically 100-200 pages for a comprehensive parts manual.
Type:
Parts Manual / Parts Catalog
Format:
Printed (likely, based on description)
Engine:
Crankcases, cylinder head, cylinders, pistons, crankshaft, con-rods, valve gear, timing.
Fuel System:
Carburetors (e.g., Amal Monobloc), intake manifolds, fuel tanks, fuel lines, petcocks.
Transmission:
Gearbox components (mainshaft, layshaft, gears, selector mechanism), clutch assembly.
Chassis And Frame:
Frame members, headstock, swinging arm, suspension linkages.
Front Suspension:
Front forks (e.g., Girling, Marzocchi), stanchions, springs, damping mechanisms.
Rear Suspension:
Shock absorbers, mounting points.
Brakes:
Front and rear brake components (drums, shoes, levers, cables, linkages).
Electrical System:
Ignition system components (magneto, coils, points, plugs), lighting components (headlight, taillight, indicators), wiring harness diagrams (often in separate manuals, but key components may be listed).
Wheels And Tires:
Rims, spokes, hubs, bearings, tire sizes.
Bodywork And Fittings:
Fuel tank, seat, fenders, side panels, handlebars, controls, exhaust system components.
Assembly Guidance:
Exploded views aiding in part identification during assembly and disassembly.
Part Identification:
Comprehensive listing of individual parts with corresponding part numbers.
Reassembly Aid:
Visual reference for correct part sequencing and orientation.
Depth:
Parts identification and cataloging, facilitating procurement of correct replacement components.
File Format:
N/A (Assuming printed product)
Print Quality:
Assumed good quality for clear illustration of parts and diagrams.
Binding Type:
Likely comb-bound, stapled, or saddle-stitched for ease of use in a workshop environment.
Paper Type:
Durable paper stock suitable for workshop use, potentially coated for longevity.
Engine Type:
Air-cooled, parallel-twin (vertical twin)
Displacement:
649 cc (39.6 cu in)
Bore X Stroke:
71 mm x 82 mm (2.80 in x 3.23 in)
Compression Ratio:
Typically 7.3:1 to 8.5:1 depending on model and tuning
Valve Train:
Overhead valves (OHV), pushrod operated.
Horsepower Est:
40-50 bhp (approximate, varies by model and tuning)
Torque Est:
40-50 lb-ft (approximate, varies by model and tuning)
Carburetors:
Typically single or twin Amal Monobloc carburetors (e.g., 30mm or 32mm). Specific sizes vary by model and year.
Fuel Type:
Leaded or unleaded gasoline (depending on era of manufacture and engine modifications).
Ignition System:
Magneto ignition (common in earlier models) or coil ignition with breaker points.
Safety Ratings:
N/A (As this is a pre-modern safety certification era motorcycle)
Braking System:
Drum brakes (front and rear). Single leading shoe (SLS) or double leading shoe (DLS) depending on model and year.
Lighting:
Headlight, taillight, brake light, (optional) turn signals.
Oil Change Interval:
Typically every 2,000-3,000 miles (3,200-4,800 km) or annually, whichever comes first. Consult the manual for specific recommendations.
Valve Clearance Check:
Every 3,000-6,000 miles (4,800-9,600 km), depending on engine condition and usage. Crucial for performance and longevity.
Chain Adjustment:
Regularly, checking for slack and proper tension before rides. Typically 1/2 to 3/4 inch of play.
Engine Oil Type:
SAE 20W/50 motorcycle-specific oil is commonly recommended for these air-cooled engines. Always verify with specific workshop manual recommendations.
Engine Oil Capacity:
Approximately 4-5 pints (2-2.5 liters), including oil in the gearbox and primary chaincase.
Gearbox Oil Type:
EP (Extreme Pressure) 90-weight gear oil is typically used. Often shared with the engine oil sump on these models.
Fork Oil Type:
Specific fork oil viscosity (e.g., SAE 10W or 20W) depending on fork type and desired damping characteristics.
Oil Leaks:
Common in older British twins due to aging seals and gaskets. Regular inspection and replacement are necessary.
Carburetor Tuning:
Amal Monobloc carburetors can be finicky and require regular adjustment and cleaning for optimal performance.
Primary Chain Tensioner:
Wear on the primary chain tensioner can lead to noise and damage. Regular checks are advised.
Pushrod Tubes Seals:
Leaking seals around pushrod tubes are a common maintenance item.
Carburetor Jetting:
Jetting needs to be appropriate for the specific model, exhaust, and altitude for best running.
Brand Legacy:
Triumph Motorcycles has a rich history dating back to 1902, renowned for its parallel-twin engines and iconic models that defined British motorcycling.
650 Twin Era:
The 650 twin platform evolved from earlier Triumph models, gaining popularity in the 1950s and 1960s for its performance and style, becoming synonymous with café racers and desert sleds.
Engine Number Era:
The engine number DU13375 signifies a production run starting in 1961 or 1962 (specific dating requires cross-referencing with Triumph production records for that prefix). The 650 twin models were produced through the 1960s.
Manufacturing Location:
Meriden, Warwickshire, England.
Iconic Status:
The T120 Bonneville, TR6 Trophy, and 6T Thunderbird are considered iconic British motorcycles, celebrated for their styling, performance, and role in motorcycle culture.
Collectible Value:
Highly sought after by collectors and enthusiasts worldwide, contributing to their lasting cultural significance.
