🏷️ Basic Information Identification Make: Harley-Davidson Model: Big Twins (Knucklehead & Flathead) Model Variant: Flathead (R, RL, RLA, W, WL, WLA, E, EL, F, FL, G, U, UL, VL, VLE, VLF) Production Years Covered: 1940, 1941, 1942, 1943, 1944, 1945, 1946, 1947 Codes Engine Codes: E, EL, F, FL, G, U, UL, VL, VLE, VLF, R, RL, RLA, W, WL, WLA 👋 Introduction Market Position Positioning: Essential resource for owners and mechanics of vintage Harley-Davidson Big Twin motorcycles, catering to restoration, maintenance, and performance enhancement. Competitive Analysis Value Proposition: Provides the same authoritative information used by Harley-Davidson dealerships, offering unparalleled accuracy and completeness compared to generic aftermarket guides. Key Features Dealership Origin: Directly sourced from factory workshop manuals, ensuring accuracy and comprehensive coverage for the specified years and models. Instant Access: Digital format allows for immediate download and use without waiting for physical delivery. 📋 Manual Details Coverage Areas Primary Coverage: Service, Repair, Workshop Secondary Coverage: Troubleshooting, Maintenance, Diagnostics, Overhaul Page Count Estimated Page Count: Approximately 500-700 (typical for factory service manuals of this era, specific count not provided but assumed comprehensive) Manual Type Type: Factory Workshop Manual / Service Manual / Repair Manual Language Language: English Format Format: ebook (PDF) 📖 Manual Coverage Systems Covered Engine: Engine overhaul, lubrication, internal components, cooling, performance tuning Electrical: Ignition system, lighting, wiring diagrams, battery, charging system, starter Fuel System: Carburetor servicing (detailed), fuel lines, fuel tanks, fuel pump (if applicable) Transmission: Gearbox overhaul, clutch operation, lubrication, shifting mechanisms Chassis: Frame inspection and repair, fork assembly, steering head, handle grips Suspension: Front fork details, rear shock absorber (if applicable), suspension tuning Brakes: Brake system servicing, drum brake adjustments, hydraulic components (if applicable), linings Wheels Hubs: Wheel bearing maintenance, spoke tension, hub servicing, tire mounting Lubrication: Lubrication points, oil types, capacities, service intervals for all components Miscellaneous: Sidecar mounting and servicing, initial servicing of new motorcycles Procedures Included Maintenance: Regular servicing, lubrication schedules, tune-ups, adjustments Troubleshooting: Comprehensive trouble charts for common issues, diagnostic procedures Repair: Step-by-step repair instructions for all major components, engine rebuilds, transmission overhauls Overhaul: Detailed procedures for complete engine and transmission disassembly and reassembly Technical Adjustments: Carburetor tuning, ignition timing, valve clearance adjustments, brake adjustments Technical Depth Depth: Factory-level detail, suitable for professional mechanics and experienced enthusiasts. Covers complete disassembly, rebuild, and precise adjustment of all systems. 📊 Manual Specifications File Format Format: PDF Searchability: Likely searchable text-based PDF, allowing for quick information retrieval. Printability: Printable pages for in-garage use. Print Quality Quality: High-resolution digital scan, replicating original factory manual quality. Binding Type Binding: N/A (Digital ebook format) Paper Type Paper: N/A (Digital ebook format) ⚙️ Engine Specifications Primary Engine Engine Type: V-twin, Air-cooled (Knucklehead and Flathead variants) Displacement: Common displacements include 61 cu in (1000cc) and 74 cu in (1200cc). Specific displacements vary by model variant (e.g., EL, FL). Bore X Stroke: Varies by specific engine variant (e.g., for 74ci E/F/G/U/UL/VL: 3.4375 in x 4.000 in; for 61ci EL/VL: 3.3125 in x 3.625 in). Precise figures detailed in the manual. Compression Ratio: Typically ranged from 5.5:1 to 7.0:1 depending on the specific engine model and intended fuel octane. Manual will provide specific figures. Performance Horsepower: Estimated 30-40 HP, varying by engine displacement and tuning. Exact figures in manual. Torque: Not typically quoted in precise lb-ft figures for this era, but high torque output was characteristic. Manual will detail engine performance characteristics. Fuel System Carburetor Types: Primarily Linkert carburetors (e.g., M-series). Manual details servicing and tuning for various Linkert models. Fuel Type: Leaded gasoline, typically with an octane rating appropriate for the compression ratio. Manual will specify. 🔧 Transmission Standard Type: 4-speed constant mesh, foot-clutch, hand-shift Gear Ratios: Specific gear ratios for each of the 4 speeds will be detailed in the manual, critical for rebuilding and performance tuning. Optional Options: No significant factory transmission options for this period; focus is on the standard 4-speed unit. Features Clutch Type: Dry multi-plate clutch, operated by foot pedal and connected to the hand shift mechanism. Lubrication Type: Primary drive lubricant (typically engine oil or a dedicated primary lubricant) and transmission lubricant. Capacities and types specified in manual. 📐 Dimensions Exterior Wheelbase: Varies by model, typically around 58-60 inches. Specific figures for each variant will be in the manual. Weights Dry Weight: Ranges from approximately 450-550 lbs, depending on model and equipment. Manual will list exact weights. 🛡️ Safety Features Ratings Crash Safety: N/A (Vehicles of this era did not undergo standardized crash testing as performed today. Focus is on mechanical integrity and safe operation.) Active Features Braking System: Drum brakes front and rear. Manual details adjustment and maintenance for optimal performance, but capabilities are primitive by modern standards. Passive Features Structural Integrity: Robust steel frame construction. Manual provides guidance on frame inspection and repair. 💡 Technology Features Infotainment Features: N/A (These motorcycles predate...