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How To Get An Old Harley-Davidson Motorcycle Running Again

How To Get An Old Harley-Davidson Motorcycle Running Again

It doesn’t take too much work to get an old Harley-Davidson on the road again, and that’s a good thing. Harley-Davidson is one of the most popular brands of motorcycles in the world, so there are many left sitting and forgotten about for years. We’ll be reviewing how, with a little work, you can get most old Harley-Davidson motorcycles back on the road fairly easily, and what you should look out for along the way.

The five things you’ll want to do whether you’re restoring a Harley-Davidson, or just getting an old Harley running again are:

  • Replacing (or at least testing) the battery
  • Draining the old gas and putting in fresh gas
  • Cleaning the carburetors (if your Harley is from 2006 or earlier)
  • Changing the oil and filter
  • Checking that the tires are okay (and checking their age)
  • Any other maintenance including brakes, spark plugs, and air filter

We’ll review all five of these topics and provide resources that will help you along the way.

Here’s a video of a 1998 Harley-Davidson Sportster XL883 that was sitting for 7 years before I got it running again. It now looks and runs as well, or better, as it did brand new.

watch this video

Watch this video!

Replacing or testing your battery

If your Harley-Davidson motorcycle has been not been ridden regularly for a while, it’s a good idea to test your motorcycle battery. Even if the motorcycle does not fire up, the battery may still be fine. Conversely, just because a motorcycle fires up, does not mean the battery won’t leave you stranded.

If you want to save money, don’t buy a new battery you may not need, and don’t suffer an avoidable breakdown. Check out these instructions on how to test a dead motorcycle battery, or watch this video:

If your motorcycle battery does need to be replaced, make sure you set up a new motorcycle battery the right way. The filling and the first charge of a new motorcycle battery is the secret to unlocking your battery’s best performance and maximizing it’s lifespan. Learn about how to fill, charge, and install a new motorcycle battery, or watch this video:

With the battery charged up, you should be able to get the bike to fire up, or at least have the motor turn over. That tells us the motor isn’t seized and we don’t have a blown main fuse.

Draining the old gas and putting in fresh gas

Now that we know the motor is in fine condition, we should work on draining the old gas out of your Harley-Davidson motorcycle’s gas tank, and getting some fresh gas in there.

Old gas starts to deteriorate after about a month. It will solidify, and the gunk it turns into can blog up your fuel hoses, carburetor jets, and fuel injectors. It’s important not to run old gas in your motor.

If you have a carbureted Harley-Davidson motorcycle, there are many ways to drain out the old gas, including from the petcock, from the carburetor, or disconnecting the tank completely from the motorcycle, and pouring it out.

If you have a fuel-injected Harley-Davidson motorcycle, you can also disconnect your tank and flip it upside down to get the old gas out. You may also want to check out a fuel transfer pump. Some use a vacuum, some use a battery, both are very effective and very easy ways of getting old gas out.

Cleaning the carburetors

If your Harley-Davidson motorcycle is from the year 2006 or earlier, it will be equipped with carburetors which could be gummed up. If that’s the case, they’ll need to be cleaned. If not, skip down to changing your oil.

There are many videos on how to clean your carburetors yourself. This can save you a lot of shop labor time. A carb job can be a couple hundred dollars. Be warned that doing it yourself can be messy, stinky, and meticulous work.

As an alternative to choosing between smelly messy work, and saving a lot of money, you can simply unhook the carburetors and bring the carburetors directly to your local motorcycle shop. That saves labor time which saves you money. Many shops have ultrasonic cleaners, so the mechanics simply take your carburetors apart, drop the pieces in the machine, and put them together when the machine is done the cleaning.

Your Harley-Davidson motorcycle should now be running beautifully and burning clean gas that won’t gum the carburetors back up again.

Changing the oil and filter

You need to change the engine oil on your Harley-Davidson motorcycle at least once a year. On many Harley-Davidson models, you’ll also need to change your transmission oil every year as well.

Old motor oil is one of your motorcycle engine’s worst enemies. Luckily there are lots of informative articles and videos on how to change oils on Harley-Davidson motorcycles including this guide to changing Sportster oil and filter, and video:

Congratulations! You can now run your motorcycle without any risk of damaging the motor or creating more work for yourself. There are still a couple things to do before you hit the road.

Checking your Harley-Davidson motorcycle’s tires

There are seven signs that your Harley-Davidson’s motorcycle tires need to be replaced, even if they have very little usage. You should check these every few weeks as you check your motorcycle’s air pressure.

The seven ways of knowing when to replace motorcycle tires are:

  • The sidewall is cracked from dry rot
  • The tire is worn out across the middle of the tire tread from a lot of use
  • The tire is worn out unevenly from under inflation
  • The tires are over seven to ten years old
  • The tires have a bulge in the sidewall from impact or defect
  • The tire has a puncture in the sidewall or near the sidewall
  • The tire has a puncture greater than 7mm (about 1/4″ to 5/16″) in diameter

You can learn about how to tell if you need to replace your motorcycle tires here, or watch this video:

Any neglected maintenance included brakes, air filter, and spark plugs

Before you hit the road, make sure your restored Harley-Davidson motorcycle is setup for success. You’ll want to make sure you cover at least the basics: brakes, air filter, and spark plugs.

Check on your brake pads and rotors and make sure the brake pads have enough meat on them and the rotors are smooth, even, and thick. These parts are fairly easy to install yourself, so save your money on shop labor, do the work yourself, and put the money you saved into top quality brake components.

You should also check your brake fluid, as it should be replaced every two years, and many motorcycles neglect this. Brand new premium brake parts won’t do you much good if you have old brake fluid. You can learn about how to check your motorcycle brake fluid here:

Air filters are also often neglected, but are key to your motor’s health and to getting the most performance out of your motorcycle. Now is a great time to learn about the different types of motorcycle air filters and consider trying out something new.

Lastly, if you really want to make sure your Harley-Davidson motorcycle is running in top condition, grab a spark plug gap tool, take your spark plugs out, and clean them. You can use a clean wire brush, or simply heat them with a torch to burn any gas or oil off.

An old neglected Harley-Davidson motorcycle is easy to get back on the road

It’s easy to get an old Harley-Davidson motorcycle back on the road by taking care of battery, fuel, fluids, and a few other components. If you have any questions, please leave me a comment and I’ll be happy to help. Consider joining the newsletter or joining me on YouTube for more helpful motorcycle content.

Next up, it’s time to learn how to keep an old motorcycle looking new.

About Adrian from YouMotorcycle

I started riding motorcycles in 2007, founded YouMotorcycle in 2009, and was working in the motorcycle industry by 2011. I've worked for some of the biggest companies in motorcycling, before going full-time self-employed in the motorcycle business in 2019. I love sharing his knowledge and passion of motorcycling with other riders to help you as best I can.

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