Preventing Backfire on Motorcycle Exhausts

close up of motorcycle exhaust
  • 1-8 hours
  • Intermediate
  • 0-200

Motorcycle exhausts create some adrenaline-rushing sounds if you're a motorcycle enthusiast. If you own a motorcycle, chances are you've experienced a backfire in the exhaust, which can cause quite a jolt for an unsuspecting rider. When a motorcycle backfires, a malfunction in your motorcycle engine mechanics is evident. By understanding why backfires happen and knowing the methods of prevention, you can keep your motorcycle running like a dream.

What Is a Backfire?

A backfire is an explosion that occurs either in the intake or in the exhaust of your motorcycle. This explosion is supposed to occur in the combustion chamber, and when it doesn't, there is an interruption in your engine's operation. It is possible to see a short-lived flame coming from the exhaust. Whether it happens in the intake or exhaust, the loud noise that results can be momentarily startling to the rider and those nearby.

What Causes Backfire?


When the engine on your motorcycle has an emission system malfunction, such as an exhaust leak or a moment of running rich or running lean, backfire can occur.

When an engine is running rich, there is more fuel present than there is air. When an engine is running lean, there is more air than there is fuel. In either case, the result is an incomplete combustion where the fuel is ignited by the heat of the exhaust, causing the loud, popping noise.

The stock muffler that comes on a motorcycle is designed specifically to ensure the complete and proper operation of the engine. When an exhaust pipe is changed, this causes an unbalanced air-to-fuel ratio. The airflow into the motorcycle is increased because of the difference in pipe design and other specifics. This difference causes backfire in the exhaust.

Other causes of backfire are bad or weak fuel pumps, low fuel pressure, or clogged fuel filters. All three of these issues have a direct effect on the air-to-fuel ratio.

Tips to Prevent Backfire

There are multiple ways to stop a motorcycle from backfiring that vary from inspecting and properly maintaining certain parts of a motorcycle to adding or replacing specific fluids.

Check Your Carburetor

Fuel can not flow properly through a dirty carburetor; this will cause a lean-running engine. If the carburetor is dirty, clean it with a high grade carburetor cleaner.

Check Your Jets

Jets clogged with debris can also prevent fuel from getting through the engine properly. If this is the case, your engine will run lean.

Add Fuel Injector Cleaner

motorcycle engine

If your motorcycle is fuel injected, using a high grade cleaner will help remove the dirt and debris trapped in your fuel lines. Consult your motorcycle's owner's manual for usage of a fuel injector cleaner for your model.

Change Fuel Grade

A low-rated fuel in your motorcycle can also contribute to dirty or clogged lines. A higher grade fuel can help to clear fuel lines and keep your fuel tank clean.