Troubleshoot My Shovelhead

Harley-Davidson engines are named for the shape of their rocker covers, a chrome piece under the gas tank, as with this Harley block head.

Shovelheads are the Harley-Davidson, Big Twin engine models that were standard equipment for Harley motorcycles from 1966 to 1984. Shovelheads made 66 horsepower on the showroom floor which is 7 to 13 horses more than current models. The term “shovelhead” or “shovels” applies to all bikes with that engine. The Shovelheads and the preceeding model known as Panheads are the most nostalgically regarded motorcycles by most American bikers. They were the last Harleys with kick starters. The model’s most obvious defect, and the one most difficult to pinpoint for most novices, is that they were famous for “marking their spot,” as dogs mark their spots, except Shovels left behind small puddles of leaking oil.


1. Check the battery. Turn the petcock to “open” or “reserve,” then switch the key and run switches on. Fully open the choke and attempt to start your electric start Shovelhead. If the starter chatters or makes no sound your battery is dead.

2. Check your gas tank. Lean left and right in quick succession and listen for gas splashing in your gas tank. If you are not out of gas and the starter operates, but your bike will not run, then the problem might be spark plugs. .

3. Check your spark plugs on both cylinders. Turn off the key and starter switches, climb off the bike and inspect your spark plug wires for obvious defects between the coil and the spark plugs on top of the shovel-shaped heads. Disconnect the plug wire from the front spark plug and remove the plug with a 13/16- inch spark plug socket and a socket wrench. The electrodes on the spark plug should be intact and covered with a light tan or light grey coating. If the plug is fouled or eroded, change the plugs to both cylinders.

4. Make note of any noises. If your motorcycle starts normally, ride around and listen to the engine. A sound like a typewriter or old-fashioned printer means that either your pushrods or tappets are loose. Squealing sounds might indicate a problem with the brakes. Brakes that work on later Shovels (early shovels used mechnical rear brakes) but do not hold (will not immobilize the bike on a hill, for example) indicate that the brake fluid in the brake master cylinder is low.

5. Locate oil leaks. If you have noticed oil where your Shovel is parked in your driveway or garage, spray foot powder spray over the entire engine. The foot powder will stick to the source of the leak. Shovelhead engines, especially those produced when Harley was owned by American Machine and Foundry, leaked from numerous locations including oil lines, base gaskets, head gaskets and oil pumps.

6. Report all problems you self-diagnose to a Harley mechanic you trust if you don’t feel comfortable making the repair yourself.