Target Audience:
AJS motorcycle owners, restorers, and classic motorcycle mechanics
Era Competitors:
Norton Commando, Triumph Bonneville, BSA Gold Star
Manual Value Proposition:
Essential resource for maintaining and restoring classic AJS models, providing factory-level technical guidance.
Covered Models:
AJS 16, 18, 20, 31, 31CS, 31CSR
Estimated Pages:
Approx. 150-200 (typical for this era's service manuals)
Type:
Service/Repair Manual
Format:
Printed (likely facsimile or original)
Engine Overhaul:
Complete engine disassembly, inspection, repair, and reassembly
Fuel System:
Carburetor tuning and overhaul (e.g., Amal Monobloc), fuel tank, fuel lines
Ignition System:
Magneto ignition, timing, spark plug specifications
Transmission:
Gearbox maintenance, lubrication, and repair; clutch operation
Suspension:
Front fork (Girling or similar) servicing, rear shock absorber maintenance
Brakes:
Drum brake adjustment and maintenance, brake shoe replacement
Electrical System:
Lighting circuits, wiring diagrams, battery maintenance
Chassis And Frame:
Frame inspection, headstock bearings, wheel bearing maintenance
Controls:
Handlebar controls, throttle and clutch cable adjustment
Bodywork:
Fender, tank, seat mounting and basic repair guidance
Preventative Maintenance:
Lubrication charts, routine checks, adjustment procedures
Troubleshooting:
Common problems and diagnostic steps for engine, ignition, and fuel issues
Repair Procedures:
Step-by-step instructions for major component overhauls and replacements
Tune Up Procedures:
Carburetor synchronization, ignition timing adjustments
Specifications And Tolerances:
Detailed technical data, measurements, and wear limits for critical components
Depth:
Comprehensive: Covers full rebuilds and in-depth diagnostics, suitable for skilled mechanics
Diagnostic Tools:
Basic mechanical tools, feeler gauges, torque wrench, timing light (optional for magneto).
Digital Format:
PDF (assumed for modern sales)
Scan Resolution:
High-resolution scans ensuring clarity of text and diagrams (if digital)
Binding:
Stapled or perfect bound (if printed facsimile)
Paper Quality:
Durable, high-quality paper suitable for workshop use (if printed facsimile)
Content Scope:
Comprehensive service and repair information, often including electrical diagrams and torque specifications.
Engine Type:
4-stroke, parallel twin (most models), single cylinder (some 16/18 variants)
Displacement:
Approx. 350cc (16/31 models), 500cc (18/20 models), 600cc (31CSR variants)
Horsepower Range:
20-35 hp (estimated, depending on model and state of tune)
Carburetor Type:
Amal Monobloc (common), possibly concentric carburetors on later models
Fuel Type:
Leaded gasoline (typical for the era), octane rating 90-95 RON recommended for modern use with additives
Oil System:
Wet sump (most models), integrated oil tank (some models)
Cooling Method:
Air-cooled
Ignition Timing:
Typically 5/16" or 3/8" before TDC (Top Dead Center) BTDC, specific to model and timing setting.
Safety Features Era:
Basic; focus on mechanical reliability. No electronic safety systems.
Braking System:
Single leading shoe (front), possibly dual leading shoe (rear on some models), drum brakes
Lighting:
Headlight, taillight, brake light (as standard for the era)
Oil Change:
Every 1,000-1,500 miles (or 3-4 months)
Valve Clearance Check:
Every 2,000-3,000 miles
Ignition Timing Check:
As needed, or every major service
Engine Oil:
SAE 20W-50 or 50 (for older engines), API SF or SG rated; consult manual for specific recommendations. Capacity: Approx. 3-4 pints.
Gearbox Oil:
EP 90 gear oil or equivalent (e.g., Castrol EPX 90)
Fork Oil:
SAE 10W or 20W fork oil (consult manual for exact type and quantity)
Brake Fluid:
Not applicable (mechanical cable actuation).
Prevalent Problems:
Oil leaks (gaskets, seals), worn valve guides, clutch slip, carburetor float issues, weak headlight output.
Ignition Problems:
Magneto wear, condenser failure, sparking at commutator.
Spark Plugs:
Champion L7Y or equivalent (verify with manual)
Air Filter:
Oil-wetted foam or wire mesh element (clean and re-oil regularly)
Manufacturer:
Associated Motor Cycles (AMC), parent company of AJS and Matchless
Historical Significance:
AJS was a renowned British motorcycle manufacturer with a strong racing heritage, particularly in the pre- and post-war eras.
1962 Context:
These models represent the later stages of AMC's twin-cylinder motorcycle development before the decline of British motorcycle manufacturing dominance.
Production Period:
The AJS 16, 18, and 20 models had long production runs, evolving through the 1950s and into the early 1960s. The 31 series was a more modern evolution.
