🏷️ Basic Information Identification Make: Harley-Davidson Model: Knucklehead Codes Engine Code Prefix: E, F, FL, U, UL Generation Generation Name: Knucklehead Production Period: 1936-1947 👋 Introduction Market Position Historical Significance: The Knucklehead represents a pivotal era in Harley-Davidson's V-twin development, known for its innovative overhead valve design and robust construction. Competitive Analysis Predecessor Models: Evolved from the previous Flathead (SV) designs, offering improved performance and reliability. Key Features Manual Value Proposition: Provides technicians and owners with the same authoritative information used by dealerships, enabling accurate diagnosis and repair. Technical Accuracy: Official Factory Service Manual (FSM) guarantees authenticity and precision of technical data. Time And Cost Savings: Empowers users to perform repairs themselves, saving on labor costs and reducing downtime. 📋 Manual Details Coverage Areas Applicable Years: 1940-1947 inclusive Engine Types Covered: OHV (Overhead Valve) and Side Valve (SV) Engine Displacements Covered: 61 cu. in. (1000 c.c.), 74 cu. in. (1200 c.c.), 80 cu. in. (1300 c.c.) Page Count Estimated Page Count: Approximately 250-400 pages (typical for FSMs of this era, exact count not provided) Manual Type Manual Type: Factory Service Manual (FSM) / Repair Manual Language Language: English Format Download Format: RAR (contains PDF files) File Type: PDF 📖 Manual Coverage Systems Covered Engine Systems: Engine Top End, Engine Lubrication System, Crankshaft, Transmission Fuel And Ignition: Fuel System, Ignition System Drivetrain: Clutch, Final Drive Chassis And Suspension: Wheels/Tires, Brakes, Suspension, Steering, Frame Electrical: Electrical System General Procedures: General Information, Engine Removal/Installation Procedures Included Maintenance: Routine maintenance, lubrication, adjustments Diagnostics: Troubleshooting, fault identification, diagnostic procedures Repair: Step-by-step repair instructions for all covered systems Rebuild: Detailed instructions for engine and component rebuilds Installation: Component and engine installation procedures Technical Depth Depth Of Coverage: Comprehensive (from basic adjustments to complete engine overhauls) Target Audience: Professional technicians and experienced DIY mechanics Diagnostic Capabilities: Advanced diagnostic procedures and troubleshooting charts 📊 Manual Specifications File Format File Compression: Requires WinRAR or compatible software for extraction Print Quality PDF Resolution: High-resolution scans of original factory documentation (assumed) Readability: Designed for clarity and ease of reading on screen and for printing Binding Type Original Binding: Not applicable (digital download) Paper Type Original Paper Type: Not applicable (digital download) Searchability Text Searchability: PDF format typically allows for text search (depends on OCR quality) ⚙️ Engine Specifications Primary Engine Engine Family: Knucklehead (OHV) and Flathead (SV) OHV Engine Displacement 1: 61 cubic inches (1000 c.c.) OHV Engine Displacement 2: 74 cubic inches (1200 c.c.) Sv Engine Displacement 1: 74 cubic inches (1200 c.c.) Sv Engine Displacement 2: 80 cubic inches (1300 c.c.) OHV Valve Train: Pushrod-actuated overhead valves Sv Valve Train: Side valve configuration Performance Horsepower Range: Approx. 30-40 HP (varies by specific model and year, exact figures not provided in product info) Torque Characteristics: Known for strong low-end torque, characteristic of V-twins of the era. Fuel System Carburetion: Primarily Linkert carburetors (specific models vary by year and engine) Fuel Type: Gasoline (specific octane recommendations in manual) 🔧 Transmission Standard Transmission Type: 3-speed constant mesh manual Clutch Type: Dry multi-plate clutch (hand operated) Features Gear Selection: Foot shift lever with heel-toe operation 📐 Dimensions Weights Dry Weight: Approx. 550-650 lbs (1940s models, varies by configuration) Payload Capacity: Not applicable (motorcycle) 🛡️ Safety Features Ratings Safety Standards Era: Reflects safety standards and designs of the 1940s. Active Features Braking System: Mechanical drum brakes (front and rear) Passive Features Frame Construction: Steel frame providing structural integrity. 💡 Technology Features Infotainment Infotainment Systems: None (pre-modern era technology) Driver Assistance Electronic Aids: None (mechanically operated systems) 🔧 Maintenance Service Intervals Oil Change Interval: Refer to manual for specific intervals; typically every 1,000-2,000 miles for the era. Tune Up Interval: Regular tune-ups recommended annually or as needed based on mileage. Fluid Specifications Engine Oil Type Sv: Non-detergent motor oil, SAE 50 or 60 (specific grades in manual) Engine Oil Type OHV: Specific grades of mineral oil, often SAE 50 or SAE 60 (refer to manual) Transmission Oil: Gear oil, typically SAE 80 or SAE 90 (specific grades in manual) Primary Chain Case Oil: Often shared with transmission oil or a specific grade depending on model year (check manual). Known Issues Oil Leaks: Common on vintage bikes; manual provides gasket and seal replacement procedures. Carburetor Adjustment: Linkert carburetors require periodic adjustment and cleaning. Ignition Timing: Critical for performance and longevity; manual details proper timing procedures. Valve Adjustment: OHV engines require regular valve lash adjustments. 📚 Vehicle History Brand Heritage Harley Davidson Legacy: Continuation of Harley-Davidson's tradition of building powerful, American-made motorcycles. Model Evolution Knucklehead Introduction: Introduced in 1936 as Harley-Davidson's first OHV V-twin, replacing the Panhead's predecessor in the evolution of the brand. Post Knucklehead: Succeeded by the Panhead model starting in 1948. Production Manufacturing Location: Milwaukee, Wisconsin, USA Wartime Production: Production was significantly impacted by WWII, with many motorcycles supplied to military forces. 🏆 Awards...