The Seasoned Wrench

,

Harley Cutting Out and Backfiring? Help Is Here!

Chase Manhattan Avatar

Last Updated:

Note: My posts may contain affiliate links. If you click on these links and make a purchase, I may receive a small commission at no extra cost to you. I only recommend products I genuinely believe in. Thanks for supporting The Seasoned Wrench!

Read my full affiliate disclaimer >>

If you’re experiencing issues with your Harley backfiring through the carb or cutting out, you’re not alone. Many riders have faced similar issues, and fortunately, there are solutions. Whether it’s due to a lean fuel mixture, a faulty ignition system, or a clogged carburetor, we’ll guide you through the possible reasons why you have your Harley cutting out and backfiring, and then show you, step-by-step, how to diagnose and fix the issue. Are you ready? Let’s get to it.

Related problem: Harley Davidson 103 Compensator Problems Revealed (+Fixed)


What Does It Mean When Your Bike Is Cutting Out and Backfiring?

When your Harley backfires through the carb, it means that an explosion is taking place in the intake or exhaust system rather than in the combustion chamber. This is often a sign of an overly lean fuel mixture, which can result in the engine stalling or cutting out.

Similarly, if your Harley is cutting out, it could be due to a malfunction in the ignition system, a clogged fuel system, or incorrect carburetor settings.

This gentleman’s culprit was indeed in the ignition system – the ignition coil itself.

Symptoms of A Lean Fuel Mixture

A lean fuel mixture is a condition where there’s too much air and not enough fuel in the air-fuel mixture that’s sent to the engine for combustion. Symptoms can include:

  1. Excessive Heat: The engine runs hotter than usual.
  2. Decreased Performance: You may notice a loss of power and speed.
  3. Backfiring: The engine may backfire on deceleration but can also occur when accelerating.
  4. Popping Noises: You may hear popping sounds from the exhaust system.

When Are These Most Commonly Experienced?

These issues are often experienced during acceleration, when the engine requires more fuel. If the bike is running lean, it may struggle to provide enough fuel, resulting in the engine backfiring through the carb or cutting out.

infographic of how a carburetor functions in motorcycles
Since many of the issues we’ll discuss are carburetor related, I always like to remind my readers of the different carburetor components and how they work together.

Your Harley Is Backfiring On Acceleration

If your Harley is backfiring on acceleration, it’s likely due to a lean fuel mixture. This can be caused by a number of issues, including a clogged air filter, incorrect carburetor settings, or a faulty fuel pump.

Your Harley Is Randomly Backfiring Through The Carb

Random backfires through the carb are often a sign of an overly lean fuel mixture. This can occur due to incorrect carburetor settings, a clogged fuel system, or a faulty ignition system.

Why Is My Carburetor Popping, You Ask?

If your carburetor is popping, it’s likely due to a lean air/fuel mixture. This can be caused by a clogged fuel system, incorrect carburetor settings, a faulty fuel pump, or even a vacuum leak.

What Are The Other Possible Causes Of A Harley Cutting Out and Backfiring?

Other possible causes of a Harley cutting out and backfiring can include a faulty ignition system, a worn-out spark plug, or even a damaged wire harness. These issues can cause the bike to run poorly, backfire, and even stall out.

How Do You Resolve These Issues?

Resolving these issues often involves identifying the underlying problem and correcting it. This can involve cleaning or replacing the air filter, adjusting the carburetor settings, replacing the fuel pump, or even replacing the ignition system.

Can Maintenance Prevent Any Of These Problems?

Regular maintenance can indeed help to prevent many of these issues. Regularly cleaning or replacing the air filter, checking and adjusting the carburetor settings, and inspecting the fuel and ignition systems can all help to keep your bike running smoothly and prevent common issues like backfiring and cutting out.

Wrapping Up and Recap of Main Points

If your Harley is backfiring through the carb or cutting out, it’s likely due to an overly lean fuel mixture, a clogged fuel system, or a faulty ignition system. By identifying the underlying problem and correcting it, you can often resolve these issues and get back on the road. Regular maintenance can also help to prevent these issues from occurring in the first place.

So next time you wonder, “Why is my carburetor popping?” or “Why does my Harley backfire through the carb?” remember that the answers, and solutions, are within your grasp. But I always like to suggest continuing your education, with something like these codes:

The Harley trouble codes you should be familiar with:
> Most Common Harley Davidson Diagnostic Codes Get Explained
> Harley Code P0562 Gets Completely Explained
> Harley Code P1356 Gets Completely Explained
> Harley Code P1510 Gets Completely Explained
> Harley Code P1632 Gets Completely Explained
> The U0184 Harley Code Gets Completely Explained
> The P2300 Harley Code Gets Completely Explained
> Harley Code B2141 Gets Completely Explained
> The U0141H Harley Code Gets Completely Explained


What causes a Harley Davidson to cut out and backfire?

A Harley Davidson motorcycle cutting out and backfiring can be caused by a variety of issues. Common causes include problems with the fuel system (like clogged fuel injectors or a dirty fuel filter), ignition system issues (such as faulty spark plugs or ignition coil), and incorrect engine timing. Air intake problems and exhaust leaks can also contribute to these symptoms.

Is it safe to ride a Harley that is cutting out and backfiring?

Riding a Harley that is cutting out and backfiring can be unsafe. These issues can lead to unpredictable motorcycle behavior, potentially causing danger while riding. It’s best to address these problems before using the motorcycle extensively.

Can fuel quality cause a Harley to cut out and backfire?

Yes, poor fuel quality can cause a Harley to cut out and backfire. Contaminated or old fuel can lead to incomplete combustion, resulting in backfires. Using the correct fuel grade and ensuring fresh fuel can help prevent these issues.

Can an exhaust leak lead to backfiring in a Harley?

Yes, an exhaust leak can cause backfiring. Leaks can disrupt the exhaust system’s pressure balance, leading to unburned fuel igniting in the exhaust pipe, which causes a backfire.

Should I adjust the carburetor if my Harley is backfiring?

If your Harley is equipped with a carburetor, improper adjustment can lead to backfiring. Adjusting the carburetor to ensure the correct fuel-air mixture can help resolve backfiring issues. However, this should be done carefully or by a professional to avoid further complications.