🏷️ Basic Information Identification Make: Harley-Davidson Model: EL "Knucklehead" Year: 1947 Codes Engine Family Code: F-Head (commonly referred to as Knucklehead) Model Designation: EL (for 61 cu in) 👋 Introduction Market Position Historical Context: The Knucklehead was Harley-Davidson's flagship overhead-valve (OHV) V-twin engine from 1936 to 1947, renowned for its distinctive rocker box covers resembling brass knuckles, hence the nickname. This era represents a significant period in American motorcycle history. Competitive Analysis Market Niche: High-performance cruiser/touring motorcycle of its time, competing with other American manufacturers like Indian. Key Features Design Philosophy: Robust, powerful V-twin engine with advanced features for the era, emphasizing durability and performance. Manual Advantage: Provides historically accurate, detailed technical information essential for preserving and restoring these iconic vintage machines. Manual User Benefit: Empowers owners and mechanics with the knowledge to maintain and repair their vintage Harley-Davidson correctly, preserving its originality and value. 📋 Manual Details Coverage Areas General Coverage: Full service, repair, maintenance, and refurbishment Specific Systems Coverage: Engine, transmission, clutch, electrical system, chassis, suspension, brakes, bodywork, fuel system, lubrication system, cooling system (air), ignition system Page Count Estimated Page Count: Varies by publisher, typically 200-400 pages for comprehensive manuals of this era Manual Type Type: Full Service Repair Manual Scope: Comprehensive repair manual, going beyond basic owner's manual tasks to cover in-depth mechanical and electrical work. Language Language: English Format Digital Format: PDF 📖 Manual Coverage Systems Covered Engine Mechanics: Detailed procedures for engine disassembly, assembly, tuning, component inspection, and rebuild. Transmission And Drivetrain: Covering the 4-speed constant mesh transmission, clutch operation, and final drive. Electrical System: Wiring diagrams, ignition system troubleshooting, lighting, charging system (generator), and battery maintenance. Chassis And Suspension: Details on fork maintenance, shock absorber servicing, wheel bearings, and frame inspection. Procedures Included Routine Maintenance: Oil changes, filter replacement, spark plug servicing, chain adjustment, brake adjustments. Diagnostic Procedures: Troubleshooting common running issues, ignition problems, and electrical faults. Rebuilding Procedures: Complete engine rebuild, transmission rebuild, carburetor overhaul, and suspension overhaul. Electrical Troubleshooting: Includes procedures for diagnosing and repairing faults in the ignition, lighting, and charging circuits, often utilizing detailed wiring diagrams. Bodywork And Trim: Instructions on fender removal/installation, tank mounting, and other cosmetic components. Technical Depth Depth: Comprehensive, suitable for professional technicians and experienced DIY mechanics. Covers detailed specifications and tolerances. Component Specifications: Provides critical torque values, clearance measurements, and tolerances for engine components, bearings, and fasteners. 📊 Manual Specifications File Format Format Details: PDF format, allowing for digital viewing and printing. Compatible with Adobe PDF Reader. Searchability: PDF format typically allows for text searching, aiding in quickly locating specific information. Print Quality Printability: Full printable specifications, allowing users to print individual pages or the entire document. Binding Type Binding For Digital: N/A (Digital Download) Paper Type Paper Type For Digital: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: 45-degree V-twin, OHV (Overhead Valve) Displacement: 61 cubic inches (1000 cc) Bore X Stroke: 3.3125 inches x 3.50 inches (84.1 mm x 88.9 mm) Compression Ratio: Typically 5.0:1 to 7.0:1 depending on variant and era specifications Performance Horsepower: Approximately 30-35 HP at 4,800 RPM (varies by specific tuning and variant) Torque: Not commonly quoted in HP, but known for strong low-end torque Fuel System Carburetor: Linkert M-Series carburetor (e.g., M74, M74B) Fuel Type: Leaded gasoline, typically 76 octane or higher Lubrication System Oil Capacity: Approximately 4 US quarts (3.8 liters) of mineral oil Oil Type Specification: SAE 50 or SAE 60 mineral oil (specific recommendations vary, consult manual) 🔧 Transmission Standard Type: 4-speed, constant mesh, foot-clutch, hand-shift Optional Optional Transmission: N/A for the 1947 model year EL Features Clutch Type: Dry, multi-plate Transmission Fluid: Harley-Davidson Transmission Oil or equivalent, often a heavy-duty gear oil 📐 Dimensions Exterior Wheelbase: Approximately 56.5 inches (1435 mm) Weights Dry Weight: Approximately 500-550 lbs (227-250 kg) depending on configuration 🛡️ Safety Features Ratings Safety Era Assessment: Safety standards of the era were significantly different from modern vehicles. Focus was on mechanical reliability and rider skill. Active Features Braking System: Drum brakes (front and rear) Passive Features Frame Construction: Steel tube frame, providing structural integrity. 💡 Technology Features Infotainment Infotainment Features: N/A - This era of motorcycle pre-dates modern infotainment systems. Focus is on mechanical function. Driver Assistance Driver Assistance Features: N/A - No electronic driver assistance features. Connectivity Connectivity Features: N/A - No electronic connectivity features. 🔧 Maintenance Service Intervals Oil Change Interval: Every 1,000-2,000 miles or annually, depending on usage and operating conditions. Tune Up Interval: Regularly required, typically involving ignition timing, carburetor adjustment, and valve lash checks. Fluid Specifications Primary Chain Case Oil: Harley-Davidson Primary Chain Lubricant or equivalent Jockey Shifter Oil: Often the same as transmission oil, or a lighter gear oil Known Issues Oil Leaks: Common due to age and seal material degradation. Requires meticulous gasket and seal replacement. Carburetor Tuning: Linkert carburetors can...