Buying a Harley Knucklehead: What to Look For

In this video, Kevin discusses what to look for and what questions to ask when looking to purchase a vintage Harley Knucklehead motorcycle. This is the first in a series of videos where Kevin walks us through the inspection and repair of a Harley Knucklehead bike. This motorcycle is actually a Knucklehead engine inside of a Harley Panhead frame.

ENGINE & FRAME

Kevin explains how to decode the engine’s VIN number which is the only manufacturer’s number that exists on a Harley of this age. There are no VIN numbers that can be found on the frame or transmission. The 1st two numbers in the vin represent the year. This lists this motor as manufactured in the year 1947. This would be the last year of production for the Harley Knucklehead engine.

Visually, Kevin can determine that the motorcycle’s frame is a later, Panhead frame. The stock Harley Knucklehead frame would be a “straight leg” style frame. The frame for this motorcycle is “wishbone” style. Both the Knucklehead engine and the Panhead frame have considerable value. Assembled with the correct corresponding (year) counterparts parts, they can become even more valuable.

It is important to inspect frame damage or frame modifications. Inspect motor mounts for damage or possible cracking. Visually inspect the motor for any major signs of damage or leaks. Make sure there are no broken fins on the heads or cylinders. If you detect a leak, try to assess if it is from simple gasket failure or originating from a cracked case.

WHEELS & BRAKES

Inspect the front and rear wheels, hubs and spokes.
Inspect the drum brake assemblies for missing, broken or damaged hardware.

FRONT END

Springer front end assemblies are excellent when regularly serviced and maintained. Visually inspect for anything that may look incomplete, bent, or altered. Springer front ends also have a lot of value. If only looking to purchase a Springer front end, you will have to shell out a pretty penny.

ELECTRICAL SYSTEM

The original Harley Knucklehead electrical system for this motorcycle would have been a 6 volt system with a magneto and with no battery. This motorcycle has been updated to a 12 volt system but still utilizes the magneto along with a generator. If the motorcycle had a battery, it would also be important to inspect the charging system.

TRANSMISSION & DRIVE & GEAR SELECTOR

Inspect the transmission for any visible signs of damage or excessive leaking. Cycle the kicker arm to verify that there is no binding. Make sure you can easily shift through all (in this case) four gears and that you can easily find neutral. Inspect for proper clutch function and feel. The Harley Knucklehead in this video was originally equipped with a rocker (foot) clutch lever with a jockey shift arm. It has been updated to a more modern hand clutch with a foot shift assembly.

FUEL SYSTEM

Inspect the fuel system from the fuel tank to the intake. Inspect and identify everything in between. What is being used for a carburetor or for a petcock? Determine if the fuel tanks are stock, aftermarket, or from a different model year Harley-Davidson.

OIL TANK/OIL SYSTEM

Inspect to see if the oil tank is original or aftermarket. Inspect for any possible damage.

HANDLEBARS & CONTROLS

Handlebars are often changed and no longer original. They are easily replaced. However, it is important to determine if handlebar controls have been altered or updated. The stock throttle assembly for a 1947 Harley Knucklehead would have a push/pull, hard cable assembly. It might also have an ignition timing control on the left side.

Look for these components or identify the absence of the two. The motorcycle in this video has an updated throttle control. It works fine but decreases the valve of this vintage motorcycle.

Kevin stresses the importance of utilizing reference materials. Service manuals, parts manuals and other publications are easily accessible. It is always possible to figure out the correct parts or repair procedures for a vintage, American Harley-Davidson.

More videos to help with your Used Harley Hunt:

Panhead for Sale: Buyer’s Guide

Used Harley-Davidson Buyer’s Guide

How To Buy Used Choppers

1984-1999 Harley-Davidson Evolution Buyers Guide

Used Sportster Buyers Guide

Buy a Used Harley and Make It Your Own Project Videos Here