Vintage Motorcycle Segment:
Classic British middleweight motorcycle, popular for its balance of performance, handling, and classic styling.
Contemporary Competitors:
BSA A50 Royal Star, Norton Commando 650/750 (later models), Royal Enfield Interceptor.
Engine Type:
Air-cooled, parallel-twin cylinder.
Frame Type:
Duplex cradle frame.
Suspension Type:
Telescopic front forks, twin rear shock absorbers.
Braking Type:
Drum brakes front and rear.
Target Audience:
Enthusiasts, owners, mechanics, and restoration specialists working on Triumph Speed Twin 5TA models.
Vehicle Make Coverage:
Triumph
Vehicle Model Coverage:
Speed Twin 5TA
Vehicle Year Coverage:
1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974
Type:
Workshop Service Repair Manual
Engine Mechanical:
Full disassembly, assembly, inspection, and repair of engine components (cylinder head, pistons, crankshaft, connecting rods, camshaft, valve train).
Carburetion:
Service, adjustment, and overhaul procedures for Amal carburetors commonly fitted to the 5TA.
Ignition System:
Information on magneto ignition, points, condenser, and coil testing and adjustment.
Transmission:
Removal, inspection, repair, and adjustment of the gearbox and clutch assembly.
Fuel System:
Tank removal, fuel line maintenance, and petcock operation.
Electrical System:
Wiring diagrams, generator/alternator testing, lighting, and horn circuits.
Frame And Suspension:
Front fork (Telescopic), rear shock absorbers, frame inspection, and steering head bearings.
Braking System:
Drum brake overhaul, adjustment, and linkage maintenance.
Wheels And Tires:
Spoke wheel maintenance, bearing checks, and tire pressure recommendations.
Bodywork And Fittings:
Fender, tank, seat, and control lever removal/installation and adjustments.
Routine Maintenance:
Oil changes, lubrication points, chain adjustment, brake adjustments, valve clearance checks, ignition timing.
Troubleshooting:
Diagnosis and rectification of common performance issues, starting problems, and operational faults.
Disassembly And Assembly:
Comprehensive step-by-step procedures for all major components.
Repair And Rebuild:
Detailed instructions for rebuilding engine, gearbox, forks, and brakes.
Adjustment:
Precise instructions for adjusting carburetors, ignition timing, clutch, brakes, and cables.
Installation:
Procedures for installing new or reconditioned components.
Depth:
Comprehensive, covering everything from basic owner maintenance to full engine and gearbox rebuilds. Includes detailed specifications and torque values.
Engine Displacement:
490 cc (30.0 cu in)
Bore X Stroke:
63 mm x 80 mm (2.48 in x 3.15 in)
Compression Ratio:
Approximately 7.3:1 (varies by tune)
Valve Train:
Overhead valves (OHV), pushrod operated.
Horsepower:
Approximately 27-30 bhp at 6,000 rpm (varies by tune and year)
Torque:
Not prominently specified in historical data, but significant low-to-mid-range torque.
Carburetor Type:
Typically single or twin Amal concentric carburetors (e.g., 376/375/389 models).
Fuel Type:
Leaded gasoline (historically), can run on unleaded with appropriate precautions or additives.
Ignition System:
Magneto ignition (Lucas or Motoplat)
Lubrication Type:
Wet sump, oil pump driven by crankshaft.
Oil Change Interval:
Typically every 2,000-3,000 miles or annually. Specific recommendation in manual.
Valve Clearance Check:
Recommended every 3,000-4,000 miles or annually. Specific figures in manual.
Chain Lubrication:
Frequent lubrication recommended, every 500 miles or as needed, especially in adverse conditions.
Engine Oil Type:
SAE 20W-50 or SAE 30 motorcycle specific oil. Manual will specify exact grade and API rating. Note: older manuals might reference specific brands or types like 'Castrol R'.
Gearbox Oil Type:
Specific gearbox oil or SAE 30/40 motor oil, depending on gearbox design and year. Refer to manual for precise specification.
Fork Oil Type:
Telescopic fork oil, typically SAE 10W or SAE 20W. Manual specifies quantity and type.
Oil Leaks:
Common due to aging seals, gaskets, and engine case construction. Requires regular inspection and maintenance.
Carburetor Tuning:
Can be finicky; requires precise adjustment of float levels, jetting, and throttle stop for smooth running.
Electrical Reliability:
Older wiring looms can degrade; magneto and charging systems may require attention.
Clutch Drag:
Can occur if clutch plates swell or if adjustment is incorrect.
Spark Plug Type:
Typically Champion N5C or equivalent, check manual for precise fitment.
Points Gap:
Approximately 0.014-0.016 inches (0.35-0.40 mm). Crucial for ignition timing.
Ignition Timing Advance:
Typically specified by piston position (e.g., 1/4 inch before Top Dead Center) or via timing marks on the magneto rotor. Manual details this precisely.
Brand Origins:
Triumph Motorcycles, a British manufacturer with a long and storied history in motorcycle production, particularly known for its parallel-twin engines.
Predecessor Model:
The Speed Twin lineage traces back to Edward Turner's iconic designs, evolving from earlier 350cc and 500cc twins.
Post 1974 Evolution:
While this manual covers up to 1974, Triumph's model line continued to evolve, eventually leading to the Bonneville and other iterations of the parallel-twin.
Manufacturing Era:
Produced during the latter years of BSA/Triumph Engineering, a period of transition for the British motorcycle industry.
Manufacturing Location:
Meriden, Warwickshire, England
