Motorcycle Popping On Deceleration: Causes And Solutions

Like any other vehicle, motorcycles also possess several problems. Likewise, popping while deceleration is one of those problems for motorcycle users.

So, what is motorcycle popping on deceleration: causes and solutions? This issue generally occurs when improper ignition and combustion occur and result in creating noise. The main culprits behind this issue are the unburnt fuel and incomplete combustion that; you need to stop to fix this issue.

In this article, we will enlighten you about multiple causes, symptoms, and solutions to the popping issue. You will also be aware of the severity and ways to prevent this problem after reading this article. Thus, keep reading till the end.

Motorcycle Popping-On Deceleration

The primary mechanism behind the pop-on Deceleration is that when the fuel enters the exhaust with air contact, it starts burning. This burning causes popping sounds. You will understand the reason better if you know the combustion process in the engine.

But remember, this burning isn’t possible without heat and air. As it’s impossible to remove the header’s excessive amount of heat, you need to manipulate the air-fuel mixture.

Generally, there are multiple reasons behind this type of issue. You must have a clear idea about those reasons before fixing them. But, before this, you need to diagnose which reasons are responsible this time. For this, you should know the distinguishing symptoms of each cause. Those are:

Reasons	Distinguishing Symptoms
Short Exhaust Line	The exhaust pipe will turn blue, orange, or yellowish due to oxidation.
Unburnt Fuel	Backfiring may occur in the exhaust pipe.
Leak On The Vacuum Line	Flashing of a check engine light or smelling gas from the vehicle.
Lean Condition	The engine will overheat, and performance will be low at lower rpm.
Rich Condition	The spark plug will seem black and moist, and you will get a poor response from the throttle.
Misalignment Of Fuel Float	You may encounter a hydraulic lock on your motorcycle.

By the way, to understand the mechanism better, watch the following video.

Causes & Solution Of Popping On Deceleration

There are multiple reasons which can cause the deceleration popping issue in your motorcycle. If you can identify those separately, you can also fix those through several easy steps. Here are a few most common causes of popping on Declaration issues and their solutions:

1. Short Exhaust Pipe

Generally, long exhaust pipes consisting of baffles can reduce the noise level. But, unlike long exhaust pipes, short ones don’t have any baffles to restrict the turbulent flow of Exhaust gas. This results in popping issues in your vehicle during deceleration.

Solutions

• You can replace the short exhaust pipe with a new long one
• Try to install an exhaust pipe that allows high flows of exhaust to stop the popping

2. Unburnt Fuel

If due to any unforeseen reasons, there remains any unburnt fuel, it will burn on the exhaust. This burning will produce some unpleasant sounds like popping during deceleration. Generally, this is the main point of numerous causes for the popping problems.

Solutions

• You must manipulate the air-to-fuel ratio to reduce the amount of unburnt fuel
• You can try tuning the carburetor to fix the faulty air-fuel level

3. Leak On The Vacuum Line

A leak on the vacuum line can cause fuel loss. If there is a significant amount of fuel loss, the engine will get less fuel for combustion. Most specifically, the amount of air will be much in the air and fuel mixture. This will cause complete fuel burning and will make a popping noise.

Solutions

• Inspect for the leak by entering white smoke through the line. Then, you can quickly point out the leak points by noticing the output points of smoke
•  Repair the leak in the vacuum line shortly

4. Lean Condition

The lean condition means the air content is more than the fuel content in the air-fuel mixture. In this case, less fuel will be ignited by the massive amount of air.

If your motorcycle is running in such conditions, incomplete fuel burning will enter the header. As a result, the exhaust will pop during declaration due to a spark.

Solutions

• You need to tune your vehicle’s fuel injector when you are decelerating
• Try to rearrange the fuel table starting from the 0% level to the red line

5. Rich Condition

The rich condition of fuel indicates the higher amounts of fuel than the air presents in the fuel-air mixture. In this case, the fuel won’t get enough air for combustion, and the unburnt portion of fuel will move toward the header.

In the header, the unburnt fuel will get enough heat and air from the header and atmosphere, respectively. And the unburnt fuel portion will get favorable conditions to burn, and this will result in creating popping noise.

Solutions

• Change the faulty spark plugs and oxygen sensor
• Maintain the fuel pressure at a moderate level
• Clean dirt from the motorcycle’s carburetor

6. Misalignment Of Fuel Float

Lower or excessive fuel levels are both adverse for the combustion system. In both cases, the combustion becomes weaker than expected and will generate unburnt fuel.

Generally, there is a float inside the fuel tank to measure the fuel level for Ignition in the tank. If the float is misaligned due to any reason, it will cause a faulty spark and eventually result in popping.

Solutions

• Align the Fuel Float accurately to the required level
• Sometimes, cracks on wear on the float may cause the misalignment. In this case, you need to repair or replace the faulty float

Cautions While Fixing  Motorcycle Popping On Deceleration Issue

While pointing out the causes behind the issue and fixing them; you must follow some cautions. Those are-

1. Get proper knowledge about the reasons for pop issues and how to diagnose them before trying to fix them
2. If you can’t figure out how to fix it, call for professional help instead of fixing anything randomly. It may cause more issues instead of solving the pop issue
3. You need to be extra cautious while tuning or cleaning the carburetor. Otherwise, you may get a serious injury while working on the carburetor
4. While refilling the fuel, fill it to an appropriate level instead of overfilling or underfilling

Severity Of Motorcycle Popping On Deceleration

Usually, the popping problem of motorcycles while deceleration isn’t too severe.  As they will not pose any potential drastic risks for the motorcycle, you need not be too concerned about this.

But, if you care about comfort while driving and the look of your vehicle, you should fix this issue shortly. Generally, the popping problem, while deceleration, will cause

• Unpleasant and discomforting noise while deceleration
• The heat of the detonation of hot air and unburnt fuel will raise the temperature of the exhaust system
• Excessive heat on the exhaust pipe will be responsible for its decoloration. Generally, the metal pipe will turn yellow or blue due to the heat
• Lingering with this issue may cause catastrophic failure in your vehicle
• There is a high risk of melting the piston and blowing up the gaskets if you don’t treat this issue for extended periods

Methods Of Preventing Motorcycle Popping On Deceleration Issue

Though the fixing methods for the popping issue are relatively straightforward, sometimes you may need to take help from mechanics. In this case, you need to pay an extra amount of money.

Also, sometimes, people keep ignoring this issue, which later may cause severe damage to motorcycles. The best way to avoid all this is to take preventive steps before the popping issue arises. Those are

1. Make sure that the carburetor of your vehicle doesn’t get dirty. Clean it regularly to keep it clean and avoid malfunctioning carburetors
2. Check the fuel filter frequently to ensure that they are functioning well. You must have to repair or replace the faulty fuel filter
3. Inspect the float on the fuel tank often so that their misalignment due to any occurrence doesn’t create a pop-on declaration
4. You need to check if there is any loose connection to the exhaust header to prevent the leak of exhaust air

FAQs

In this section, we answer several most asked questions about the popping on the declaration of motorcycles.

Conclusion

Popping in the exhaust while deceleration might be a minor issue, but still, you need to resolve this. Most importantly, you must have a clear idea about motorcycle popping on deceleration: causes and solutions. Without it, you won’t successfully fix the popping problems in the exhaust.

You can save the repair cost by fixing it yourself, but it poses a risk of damaging the vehicle or getting injured. We will suggest you ask for help from a professional mechanic if you are not skilled enough. However, you can easily avoid this complexity by following some methods to prevent popping.