Target Audience:
Mechanics and DIY enthusiasts
Value Proposition:
Provides essential data, characteristics, instructions, and methodology for repair interventions, offering detailed procedures, explanations, and pictorial diagrams.
Delivery Method:
Instant Download
Completeness:
100% Complete and Intact
Specific Components:
Engine, Transmission, Clutch, Fuel System, Electrical System, Chassis, Suspension, Brakes, Bodywork, Lubrication
Type:
Workshop Service Repair Manual
Transmission Service:
Yes
Electrical Diagnostics:
Yes
Suspension And Forks:
Yes
Brake System Maintenance:
Yes
Troubleshooting Guide:
Yes
Disassembly And Assembly:
Yes
Adjustments And Settings:
Yes
Component Replacement:
Yes
Depth:
Comprehensive (from basic maintenance to complete engine rebuilds)
Level Of Detail:
Step-by-step instructions with detailed explanations and pictorial diagrams
Engine Type:
OHV Vertical Twin
Displacement:
249cc (approx.)
Bore X Stroke:
57mm x 48.8mm (typical for 3TA)
Horsepower Estimate:
Approx. 17-18 BHP (at 7000 RPM)
Torque Estimate:
Approx. 15-16 lb-ft (at 5000 RPM)
Carburetor Type:
Single Amal Monobloc (typically 22mm or 24mm)
Fuel Type:
Unleaded gasoline (with appropriate octane rating and potential lead substitute additive)
Ignition Type:
Coil and Distributor (or Magneto for some earlier models), Lucas or Wipac ignition systems common
Oil Change Interval:
Typically every 1,500-2,000 miles or annually (details within manual)
Valve Clearance Check:
Recommended at initial service and every 3,000-4,000 miles (details within manual)
Engine Oil Type:
SAE 20W/50 or SAE 30 (mineral oil recommended for period correct engines, specific grades provided in manual)
Transmission Oil Type:
Gear oil (specific viscosity and type detailed in manual)
Primary Chaincase Oil Type:
Engine oil (same as engine oil, specific capacity detailed in manual)
Common Wear Points:
Valve guides, piston rings, clutch plates, gearbox bearings, electrical connections.
Carburetor Issues:
Float bowl leaks, needle wear, jet clogging, leading to rough running or fuel leaks.
Electrical Faults:
Fraying wiring, faulty ignition coils, worn distributor points, headlight/taillight issues.
Spark Plug Type:
Champion L7Y or equivalent (specific gaps provided in manual)
Tire Pressure Front:
Approx. 24-26 PSI (laden/unladen variations provided in manual)
Tire Pressure Rear:
Approx. 28-30 PSI (laden/unladen variations provided in manual)
Primary Chain Tension:
Specific slack measurement and adjustment procedure detailed in manual.
Wheel Alignment:
Wheel spoke tensioning and trueing procedures are vital and covered.
Manufacturer Origin:
United Kingdom
Series Introduction:
The 3TA 'Twenty One' was a development of Triumph's earlier unit-construction parallel twins, positioned as a more practical and accessible model.
Production Period:
The 3TA variant was produced from the late 1950s into the mid-1960s, with this manual covering up to 1974, indicating ongoing support or specific export markets.