The Harley Knucklehead 1940-1947 Service Repair Manual is a comprehensive guide for anyone looking to maintain and repair their classic motorcycle. This manual covers everything you need to know, from basic maintenance to complex engine repairs. It provides detailed instructions, diagrams, and illustrations to guide you through each procedure.

This manual includes sections on:

* General Information: Learn about the history, specifications, and features of the Harley Knucklehead motorcycle.
* Maintenance: Discover routine maintenance schedules and procedures for keeping your motorcycle in optimal condition.
* Chassis: Find information on the frame, suspension, wheels, tires, and brakes.
* Fuel System: Learn about the carburetor, fuel lines, and fuel tank.
* Cooling System: Understand the cooling system's components and how it works.
* Engine: Explore the engine's inner workings, including the cylinders, pistons, valves, and camshaft.
* Clutch: Learn about the clutch mechanism and how to adjust and repair it.
* Engine Lubrication System: Understand the oil system and how to change the oil.
* Engine Removal/Installation: Detailed instructions on how to remove and reinstall the engine.
* Drive: Explore the transmission and final drive components.
* Transmission: Learn about the transmission's gears, shafts, and clutch mechanism.
* Wheels/Tires: Information on wheel types, tire sizes, and maintenance procedures.
* Final Drive: Explore the final drive system, including the chain or belt, sprockets, and axle.
* Brakes: Learn about the brake system, including the calipers, rotors, and master cylinder.
* Suspension: Explore the front forks and rear suspension components.
* Steering: Understand the steering mechanism and how to adjust it.
* Frame: Information on the frame's construction and how to repair it.
* Electrical System: Learn about the electrical system, including the battery, starter, generator, and wiring.
* Wiring Diagram: Detailed wiring diagrams for troubleshooting electrical problems.

This manual will empower you to tackle any repair job with confidence. Whether you're a seasoned mechanic or a novice DIY enthusiast, this resource will provide the knowledge and guidance you need to keep your Harley Knucklehead running smoothly.

The Harley-Davidson Knucklehead, produced from 1936 to 1947, is a legendary motorcycle engine that revolutionized the world of motorcycling. Its distinct, iconic design and powerful performance cemented its place in history, earning it the nickname "Knucklehead" due to the exposed rocker arms that resemble knuckles. This air-cooled, 45-cubic-inch (740 cc) V-twin engine is renowned for its smooth, powerful, and reliable performance, making it a favorite among enthusiasts. While its predecessor, the Flathead, was considered a solid engine, the Knucklehead was a significant leap forward in terms of technology and performance. The Knucklehead incorporated a number of innovative features like a fully-enclosed valve train, an overhead camshaft, and a redesigned cylinder head. These advancements resulted in a more powerful and efficient engine that could deliver speeds exceeding 80 mph, a feat previously unheard of for motorcycles.

The Knucklehead's popularity extended beyond its performance. Its unique design, characterized by its distinctive, exposed rocker arms, became a symbol of Harley-Davidson's craftsmanship and heritage. The Knucklehead engine was available in various models, including the FL, UL, and EL, each tailored to different riding styles and purposes. The FL, known for its touring capabilities, was popular among long-distance riders, while the UL and EL were favored for their nimble handling and agility. The Knucklehead's impact on motorcycle history is undeniable. Its technological advancements, reliable performance, and unique design made it a cornerstone of Harley-Davidson's reputation as a manufacturer of high-quality, powerful motorcycles. Today, the Knucklehead remains a coveted classic, sought after by collectors and enthusiasts alike for its historic significance and timeless appeal.