A backfire of the engine makes the motorcycle pop on acceleration. Installing new exhaust, incorrect octane and screws can also cause this.
So, what are the solutions for motorcycle popping on acceleration? Balancing the air-gasoline mixture is the key here. To do so, replacing the seal or gasket to fix leakage, ensuring timely ignition and proper compression, and cleaning air and fuel filters are necessary. Besides, carb sync and resettling the jets are also important.
Likewise, if you are using the high-performance exhaust in a fuel-injected engine, EFI should be reset. Using proper oil and gas is also important in this case. Read the article to learn more about the issues with solutions.
What Does Popping Mean for A Motorcycle?
Unburnt fuel’s ignition in the exhaustion or the intake causes the popping noise in your motorcycle. This incident is often known as a backfire.
The power stroke of your motorcycle’s internal explosion engine occurs when an ignited blend of compressed gasoline and air pushes down the piston. In that case, the ratio of air and gasoline should be 14.7:1.
However, if for some reason the ratio goes in favor of air or gasoline, which is called too lean or too rich situation respectively, causes this backfiring. Watch this video to learn more:
It is possible, in such circumstances, that combustion of the mixture of gasoline and air does not happen entirely inside the cylinder of the engine chamber. But rather takes place in the infusion system or the emanation tube. Thus, the backfire refers to combustion occurring in the wrong place.
This situation is common in motorcycles carrying carburetors or the ones which are run through fuel injection. However, the probability is higher in a carburetor-induced one as the air-gas combination’s control depends on electronics in such motorcycles.
Motorcycle Popping On Acceleration: Causes & Solutions
Have a look a the table below for an overview of the causes and solutions.
| Causes | Solutions |
| Leakage | Replace the gasket/seal at the point of vacuum leakage |
| Ignition System Defect | Get help from the user’s manual to fix the defect which is causing mistimed ignition |
| Low Compression | Inspect the engine for compression issues and fix the issue |
| Jammed Air Filter | Frequently wash the air filter Consider a replacement if the situation is too bad |
| Jammed Fuel Filter | Wash the fuel filter or swap it if necessary Make sure the carburetor has been overhauled and synchronized |
| Replacing Stock Exhaust | There should be new carburetor jets installed to cope with the new exhaust The EFI system should be reset in the case of fuel-injected engines |
| Incorrect Octane Number | Use the recommended gasoline according to the manufacturer |
| Misadjusted Screw | Properly place the misadjusted screws |
Motorcycle Popping On Acceleration: Causes
Imbalance in the air-gasoline combination gives birth to backfiring, which results in the popping noise. Let’s look at the reasons for such an imbalance in acceleration
1. Leakage
There may be leaks in your motorcycle intake system that permit more air than is necessary into the cylinders of the engine. And this is enough to cause a backfire.
Moreover, if there is a leak in the exhaust line, the unburnt fuel can leak through it, causing the backfire through ignition.
2. Ignition System Defect
There is a possibility of spark plugs igniting the air/gas mixture prior to the closure of the inlet valve. But it’s ok if there is nothing wrong with the ignition system that ensures accurate ignition timing.
3. Low Compression
If the compression level is lower than optimum, this can permit the entrance of air or gas into the carburetor, which can cause a backfire.
4. Jammed Air Filter
If the air filter is dirty and jammed, this can prevent sufficient airflow to the carburetor, allowing the air/gas mix to be imbalanced.
5. Jammed Fuel Filter
If the fuel filter or jet tubes are jammed, the carburetor will not receive sufficient fuel. Thus, it will result in extremely lean fuel-air ratios and cause an engine to backfire.
6. Replacing Stock Exhaust
In an engine that comes with a carburetor or fuel injection can result in more additional airflow into the engine. Thus, it results in a thin mixture of air and gasoline, which can cause a backfire. Not resetting carburetor jets or the EFI system respectively after substituting your factory exhaust cause this issue.
7. Incorrect Octane Number
There is a recommended octane rating for all the motorcycles set by the manufacturers. If you don’t use the recommended one, this can cause an imbalance in the air-gasoline blend.
8. Misadjusted Screw
Only a misplaced or misadjusted screw from the air system or fuel system can be enough to cause a backfire in rare situations.
Motorcycle Popping On Acceleration: Solutions
This mainly happens in carburetor-induced motorcycles where the carburetor is full of gasoline, causing the air-gas blend to become imbalanced. You can easily get to know this by inspecting your spark plugs for potential blackness. The other way is to smell the exhaust which isn’t the healthiest option.
Nevertheless, if you do so and get a strong gassy odor, excessive gasoline supply is the reason. However, a rich carburetor can be fixed through the adjustments of screws that are responsible for the quantity of the supplied fuel the engine gets during idle.
Even if the proper installation of the screws doesn’t thin the mixture, your carburetors might require replacement. On the other hand, not having carburetors make motorcycles with fuel injection less apt to air-gas mix issues.
Nevertheless, you can face such issues in a fuel-injected motorcycle too. And the best solution is to take professional help in this regard.
How to Know If There Is A Leakage?
Follow this guideline to know if there is a leakage in the exhaust.
- The best way to detect a leak is to listen to the noise. If you hear a ‘hiss’ from the system, there can be a leak if it is accompanied by the popping of your motorcycle.
- The next thing to check is the stooped pipe. If there is a stoop outside the pipe, the seal might be damaged inside the line.
Is Popping While Acceleration Bad for Motorcycles?
As this pop is caused by backfire, which is basically a combustion defect, this can cause power loss. In an ironic twist, many riders purposely backfire costly exhausts in order to gain additional power.
Moreover, running a bike with an imbalanced air-gasoline blend causes the interior temperatures to increase. In other words, this process is more like frying the engine of your motorcycle. If this continues for an extended period, the engine will wear out in no time.
FAQs
Let’s look at some of the frequently asked questions and their answers
Q. Will a Bad Fuel Pump Cause a Backfire?
Ans. A bad fuel pump can cause the percentage of air to increase in the air-gasoline mixing, which can end up backfiring the engine.
Q. How much Popping is Acceptable in a Motorcycle?
Ans. You shouldn’t worry if you hear a little pop from time to time. However, if the sound increases and persists, it’s time to check for problems.
Q. What is the Cause of Motorcycle Backfiring during idling and Acceleration?
Ans. An intake leakage can be the potential cause of it. To be sure, you can spray carburetor cleaner close to the intake and check for any change after pulling the throttle.
Final Thoughts
Popping at a moderate level while accelerating is not concerning and is considered to be cool. However, if the pop is loud, backfiring is the imminent cause. So, too reach or too lean air-gasoline mixture is the reason here.
Therefore, ensuring the proper air and gasoline ratio and fixing all the causes that result in the imbalance can fix the issue. Hopefully, today’s article will give you in-depth knowledge regarding this.