The Harley Davidson Knucklehead 1940 All Service Repair Manual is a comprehensive guide for owners and enthusiasts seeking to maintain and repair their classic motorcycles. This detailed manual covers a wide range of topics, ensuring you have the information necessary to perform various tasks, from basic maintenance to complex repairs.

The manual includes sections on general maintenance, troubleshooting, engine service and repair, transmission service and repair, brake system, wiring diagram, electrical system, suspension, periodic lubrication, steering, cooling system, fuel injection/fuel system, emission system, engine control system, chassis/body, restraint system, axle, and more. With step-by-step instructions, illustrations, and detailed diagrams, this manual provides clear and concise guidance, allowing you to confidently tackle any repair or maintenance project on your 1940 Harley Davidson Knucklehead.

The Harley-Davidson Knucklehead, produced from 1936 to 1947, represents a pivotal moment in the evolution of American motorcycles. This iconic machine, aptly named for its distinctive "knuckled" rocker arm design, marked a significant departure from previous Harley models. The Knucklehead's engine, a 45-cubic-inch (740 cc) V-twin, featured a number of innovations that set it apart from its predecessors. These included a fully enclosed valve train, which reduced noise and wear, and a more robust crankshaft, allowing for higher engine speeds and increased power. The Knucklehead also boasted an improved oil system, which provided better lubrication and extended engine life. This combination of advancements resulted in a motorcycle that was not only more powerful and reliable, but also smoother and quieter than any Harley-Davidson before it.

The Knucklehead, with its sleek styling and powerful engine, quickly gained popularity among riders. It was chosen for a variety of applications, from everyday transportation to police duty and long-distance touring. The motorcycle's durability and performance made it a favorite among riders who sought a reliable and exciting machine. Its iconic status further solidified with its appearance in the "Easy Rider" film, where it was ridden by Peter Fonda. This solidified its place in motorcycle history as a symbol of freedom and American cool, inspiring generations of riders and motorcycle enthusiasts. The Knucklehead continues to be coveted by collectors and enthusiasts today, representing a unique blend of vintage charm and groundbreaking engineering.