Model Generations Covered:
WL, WLA, WLC, U, UL, UH, ULH, R, RL, VL series
Model Years Covered:
1940, 1941, 1942, 1943, 1944, 1945, 1946, 1947
Engine Codes:
Various Flathead V-twin configurations (e.g., 45 cubic inch 'W' series, 74 cubic inch 'U' series)
Target Audience:
Owners, mechanics, and restorers of 1940-1947 Harley-Davidson Flathead motorcycles, particularly military WLA/WLC models and civilian U/UL, R/RL variants.
Value Proposition:
Provides the definitive, official factory repair information, essential for accurate maintenance, troubleshooting, and restoration of these iconic vintage motorcycles.
Manual Essentiality:
Crucial for anyone performing repairs or restoration on these models, offering factory-correct procedures and specifications unavailable in generic guides.
Engine Systems:
Engine assembly, disassembly, inspection, repair, troubleshooting, carburetion (e.g., Linkert M-series), ignition systems (e.g., Magneto, battery ignition), lubrication systems, cooling systems (air-cooled).
Transmission Systems:
Gearbox disassembly, inspection, repair, clutch operation and adjustment, shifting mechanisms.
Chassis And Suspension:
Frame inspection, front fork (e.g., Springer, leading-link) service and repair, rear suspension (if applicable), wheel bearing maintenance, steering head adjustment.
Braking Systems:
Brake shoe adjustment, drum brake disassembly and service, brake linkage.
Electrical Systems:
Wiring diagrams, lighting systems, horn, generator/battery charging system, starter motor (if applicable).
Fuel Systems:
Fuel tank, fuel lines, fuel filters, carburetor servicing and tuning.
Exhaust Systems:
Muffler and pipe service, mounting.
Bodywork And Fittings:
Fender mounting and alignment, seat assembly, handlebar installation and adjustment, control cable routing and adjustment.
Maintenance Procedures:
Regular servicing, lubrication points, fluid changes, filter replacements, ignition timing adjustment, carburetor tuning, brake adjustments, tire pressure checks.
Diagnostic Procedures:
Troubleshooting guides for common starting issues, running problems, electrical faults, and mechanical noise.
Repair Procedures:
Detailed step-by-step instructions for component disassembly, inspection, repair, and reassembly of all major systems.
Overhaul Procedures:
Complete engine rebuild procedures, transmission overhaul, and fork rebuilding.
Special Tool Identification:
Identification of required special tools for specific repair operations.
Depth Of Coverage:
Comprehensive factory-level detail, suitable for experienced mechanics and dedicated restorers. Covers everything from basic adjustments to complete engine teardowns and rebuilds.
File Type:
PDF (Portable Document Format)
Searchability:
Likely OCR'd for text searchability, allowing quick access to specific topics.
Scan Resolution:
Expected to be high-quality scans of original factory documents, ensuring legibility of text and diagrams.
Binding For Download:
N/A (Digital download format)
Original Manual Paper:
Original manuals were typically printed on durable paper stock suitable for shop environments.
Engine Type:
Overhead Valve (OHV) 'Flathead' V-twin
Displacement 45 Cu In:
45.24 cubic inches (741.5 cc)
Displacement 74 Cu In:
73.74 cubic inches (1208.3 cc)
Bore Stroke 45 Cu In:
3.00 x 3.125 inches (76.2 x 79.4 mm)
Bore Stroke 74 Cu In:
3.3125 x 3.3125 inches (84.1 x 84.1 mm)
Horsepower Approx 45 Cu In:
Approximately 23-25 hp (varies by model and tuning)
Torque Approx 45 Cu In:
Torque figures not typically published in the same way as modern vehicles, but known for strong low-end torque.
Carburetor Type:
Linkert M-series (e.g., M51, M74, M75, M76 depending on model and year)
Fuel Type:
Gasoline (petrol), octane rating appropriate for the era, often higher octane for performance models.
Ignition Type:
Magneto ignition (common) or Battery & Coil ignition systems.
Oil System:
Total loss oiling system (oil is fed to the engine and exhausted).
Oil Change Interval:
Frequent oil changes recommended due to the total loss system; typically every 500-1000 miles or as specified by the manual.
Tune Up Frequency:
Regular tune-ups involving ignition timing, carburetor adjustment, and spark plug checks are crucial for optimal performance and reliability.
Engine Oil Type:
Viscosity grades such as SAE 50 or SAE 60 (non-detergent oils often recommended for vintage engines) depending on ambient temperature and manual recommendations. Actual specifications would be in the manual.
Transmission Oil Type:
Gear oil, typically SAE 90 or similar, as specified in the manual.
Primary Chaincase Oil:
Engine oil or specific primary lubricant as per manual.
Common Wear Items:
Worn piston rings, valve guides, main bearings, transmission gears, clutch plates, and aging electrical components.
Carburetor Tuning:
Linkert carburetors require regular adjustment and cleaning for smooth operation.
Ignition Timing:
Proper ignition timing is critical and needs periodic verification.
Oil Leaks:
Vintage motorcycles, especially Flatheads, are prone to minor oil leaks from seals and gaskets; careful gasket sealing is important.
Part Numbers:
The manual will contain many original part numbers, crucial for sourcing correct replacement parts. Example part numbers for common items like spark plugs, filters, or gaskets would be detailed within.
Harley Davidson History:
Harley-Davidson has a long-standing history dating back to 1903, renowned for its V-twin engines and iconic motorcycles.
Flathead Engine Development:
The 'Flathead' engine design, introduced in 1929, was a cornerstone for Harley-Davidson, offering reliability and torque for decades. The 45 cubic inch (WL series) and 74 cubic inch (U series) were dominant civilian and military models.
Wartime Production:
During WWII, Harley-Davidson produced large numbers of the WLA (Army) and WLC (Canadian/Allied forces) variants, making these models particularly significant in military history.
Post War Transition:
Post-war civilian models continued the Flathead lineage before the introduction of the Panhead engine.
