This comprehensive Harley Davidson Knucklehead Flathead Workshop Manual covers models from 1940 to 1947. It provides detailed instructions for servicing, repairing, and maintaining your classic motorcycle. The manual is a valuable resource for both professional mechanics and DIY enthusiasts, offering clear step-by-step instructions, illustrations, and specifications. Dive into topics like routine maintenance, tune-up procedures, engine removal and installation, cylinder head and valve train repair, engine block servicing, lubrication systems, intake and exhaust systems, cooling and heating systems, fuel and emissions systems, transaxle, clutch, manual and automatic transmission, differentials, driveshafts, steering, suspension, brakes, bodywork, heater and air conditioning, electrical systems, engine repair, air conditioning, exhaust, emissions control, ignition, steering, and wiring diagrams. The manual also covers essential procedures like valve timing, chain and gear replacement, general removal and installation instructions, safety precautions, special tools, tensioner adjustments, tightening torques, timing marks, valve timing instructions, tensioner release and reset methods, chain routing, and sprocket/gear valve timing marks. This manual is your one-stop resource for everything you need to keep your Harley Davidson Knucklehead Flathead running smoothly.

The Harley-Davidson Knucklehead, produced from 1936 to 1947, is a legendary motorcycle that revolutionized the motorcycle world. Its name derives from the distinctive, knuckle-shaped rocker arm covers that encased its innovative overhead valve (OHV) engine. This design, a departure from the traditional flathead design, offered significant performance advantages, including increased horsepower and reduced vibration. The Knucklehead engine, with its unique 45-degree V-twin configuration and cast-iron cylinder barrels, became synonymous with American power and reliability, making it a popular choice for both touring and racing.

The 1940-1947 Knucklehead models, available in various styles such as the EL (for "Electra" or "Electric"), FL (for "Full Dress"), and UL (for "Underslung" or "Utility"), were produced during a pivotal period in American history. The outbreak of World War II in 1941 significantly impacted production, as Harley-Davidson shifted its focus to manufacturing military motorcycles. Despite the wartime constraints, the Knucklehead's popularity endured, and it continued to be produced after the war, cementing its legacy as a symbol of freedom and American ingenuity. The Knucklehead's robust design, coupled with its iconic styling, has made it a highly sought-after collectible, and even today, these historic machines continue to captivate enthusiasts.