Model:
16M, 16MS, 16MC, 16MCS, 18, 18S, 18C, 18CS
Product Name:
AJS 16M 16MS 16MC 16MCS 18 18S 18C 18CS Service Maintenance Manual 1951
Era Context:
This manual covers a pivotal period for post-war British motorcycle manufacturing, where AJS was a respected marque known for robust and reliable machines.
Competitors:
Competed with other British manufacturers like BSA, Triumph, Norton, and Royal Enfield, offering dependable everyday transportation and sporting capabilities.
Vehicle Appeal:
These AJS models were renowned for their comfortable ride, accessible performance, and relative simplicity, making them popular for both commuting and touring.
Engine Systems:
Engine overhaul, cylinder head, piston, crankshaft, camshaft, valve gear, lubrication system, cooling system (air), fuel system (carburetor, fuel tank, lines), ignition system (magneto, spark plugs).
Transmission Systems:
Gearbox (pre-unit construction), clutch operation and adjustment, gear shifting mechanisms, lubrication.
Chassis Systems:
Frame, front forks (telescopic), rear suspension (swing arm, shock absorbers), steering system, wheel bearings, brake system (drum brakes front and rear), footrests, handlebars.
Electrical Systems:
Ignition system (magneto timing and maintenance), lighting (headlamp, taillight, brake light), wiring diagrams (basic for the era).
Bodywork And Fittings:
Fuel tank, seat, mudguards, chain guard, instruments (speedometer), exhaust system.
Maintenance Procedures:
Regular servicing, lubrication schedules, valve clearance adjustment, ignition timing, brake adjustment, chain adjustment, carburetor tuning.
Repair Procedures:
Engine rebuild, gearbox overhaul, fork seal replacement, brake shoe replacement, bearing replacement, electrical component testing.
Troubleshooting Guides:
Common running issues, starting problems, electrical faults, braking issues, gearbox noise.
Assembly And Disassembly:
Detailed instructions for dismantling and reassembling major components.
Diagnostic Capabilities:
Provides specifications for checks and adjustments, enabling basic diagnosis of performance issues.
Rebuild Instructions:
Comprehensive enough for full engine and gearbox rebuilds, including torque values and clearance specifications.
Specifications Detail:
Includes essential technical data such as bore x stroke, compression ratios, valve timing, and clearances.
Digital Format Quality:
If PDF, expect clear scans of original pages; text searchability may vary based on OCR quality.
Print Quality Description:
Original manual would have been printed with black ink on paper, likely with line drawings and diagrams.
Binding Description:
Original would have been bound for durability, likely stapled or sewn for workshop use.
Paper Type Description:
Typically newsprint or slightly heavier stock for period workshop manuals.
Engine Type:
4-stroke, single-cylinder (OHV)
Engine Displacement:
AJS 16 series: 347cc (approximately); AJS 18 series: 498cc (approximately)
Bore X Stroke:
AJS 16: 64mm x 69mm; AJS 18: 82.55mm x 93mm (typical values)
Compression Ratio:
Typically around 6.5:1 to 7.0:1
Horsepower Output:
AJS 16: approx. 18-20 bhp; AJS 18: approx. 25-28 bhp (at specified RPM)
Carburetor Type:
Typically a single Amal carburetor (e.g., Amal 276 or similar).
Fuel Type:
Leaded petrol (common for the era); modern equivalents with octane booster may be required.
Fuel Delivery:
Gravity feed from tank via fuel line.
Transmission Type:
4-speed, constant mesh, foot-shifted (right-foot operation for early models, left-foot for later 1951 models, check specific model variant).
Clutch Type:
Wet multi-plate clutch, cable operated.
Gearbox Construction:
Pre-unit construction (engine and gearbox are separate units).
Era Safety Standards:
Reflects 1950s safety standards; lacks modern safety features. Emphasis on rider skill and machine condition.
Braking System:
Drum brakes, front and rear. Single leading shoe typically.
Lighting:
Headlight, taillight, and stop light (if fitted).
Oil Change Interval:
Typically every 1,000-1,500 miles (1600-2400 km) or annually, depending on usage.
Valve Clearance Check:
Every 2,000-3,000 miles (3200-4800 km).
Ignition Timing Check:
As needed, or during major services.
Engine Oil Type:
SAE 50 or 20W/50 motorcycle-specific oil for warm conditions; SAE 20W/30 for colder conditions. Mineral oil is standard.
Gearbox Oil Type:
EP 80W/90 gear oil or SAE 50 motorcycle oil.
Fork Oil Type:
Telescopic fork oil, typically SAE 10W or 20W.
Common Wear Points:
Valve guides, piston rings, clutch plates, gearbox bushings, worn Amal carburetors, dynamo drive bushes.
Electrical Quirks:
Magneto ignition can be sensitive to moisture and requires proper timing. Wiring can be brittle with age.
Frame And Suspension Wear:
Worn fork bushes, shock absorber damping, and frame headstock bearings are common.
Carburetor Issues:
Amal carburetors can suffer from wear in the throttle slide and needle jet, leading to poor running.
Manufacturer:
Associated Motor Cycles (AMC) Group, incorporating brands like AJS and Matchless.
Model Lineage:
The Model 16 and 18 were successful middleweight and heavyweight singles, respectively, evolving from earlier AJS designs and sharing many components with Matchless models.
Production Period:
These specific variants were predominantly produced in the late 1940s and early 1950s.
Manufacturing Location:
Plumstead, London, England.
