✅ Reasons why a motorcycle shoots into the carburetor

Owners of motorcycles not only made in Russia, but also of foreign cars often face the problem of “shooting” from the muffler. This happens due to improper care of the air-fuel mixture ignition system. The motorcycle shoots the muffler in several cases:

when using low-quality gasoline;
malfunction of the electronics system responsible for fuel supply;
gasoline does not enter the combustion chamber in pure form;

In such cases, you don’t need to wonder why the muffler on a motorcycle shoots. Poor quality gasoline has a very high combustion temperature due to the addition of water, so it does not ignite completely. The remaining drops fall on the walls of the heated muffler . Their ignition creates pops.

The motorcycle also shoots into the muffler when releasing the gas. The lower the pressure created in the internal combustion chamber, the more droplets enter the muffler. On some bikes, fuel accumulates in the muffler, followed by rare but very loud bangs.

Most often, but not always, owners of the Russian motorcycle industry face this problem. For example, a Ural motorcycle shoots into the carburetor. This occurs due to direct clogging of gasoline in the carburetor itself. To avoid this problem, it is necessary to constantly clean the filters and change the consumables responsible for cleaning the engine. Proper operation of your bike will not only ensure good engine performance, but will also maintain factory specifications.

The motorcycle shoots into the muffler: why does this happen and how to solve the problem?

On domestic motorcycles, a problem often arises associated with the appearance of loud sounds in the muffler. Even drivers of foreign vehicles often suffer from “machine gun bursts” that accompany a sharp increase or decrease in speed. Getting rid of this trouble can be quite difficult. However, if you understand why a motorcycle shoots its muffler, you can eliminate loud noises that disturb public peace.

Messages [18]

1↑ Topic by terminator983495 04/25/2014 21:38:13

terminator983495
Assistant
Inactive

Registered: 23-09-2012
Messages: 177
Reputation:

Topic: shooting in Glushak

shoots at the muffler on the left engine, the Ural motor is worth the electronic ignition, sovek Sedni passed the norm, it was in the other end, I went, it started clapping and there were interruptions in the left engine, what could it be?

2↑ Reply from Zhman 04/26/2014 18:50:50

Zhman
Experienced
Inactive

Registered: 23-06-2012
Messages: 132
Reputation: 13

Re: shooting in the jammer

I threw it away immediately, the next day I bought it, and realized that it was all x. I! I have nothing against electronics, but the old system is more reliable.

3↑ Reply from Roma 04/26/2014 21:00:43

Roma
Uralomaniac
Inactive
Name: Roman

From: Shentala, Samara region.
Registered: 23-10-2012
Messages: 6 156
Reputation: 521
Motorcycle: Ural IMZ 8.103-10

Re: shooting in the jammer

This is why I have a BSZ from the 90s, factory!

4↑ Reply from drakone 04/27/2014 05:53:44

on drakone
Elder
Inactive
Name: Albert

From: Omsk region. Omsk city
Registered: 07-12-2012
Messages: 4 972
Reputation: 125
Motorcycle: Ural 8.103.10, GAZ 31029

Re: shooting in the jammer

This is why I have a BSZ from the 90s, factory!

Concurrent symptoms

As a rule, the situation is accompanied by a number of other signs:

unstable operation of the internal combustion engine in idle mode;
difficulty starting;
loss of power and throttle response of the power unit;
rapid overheating of the motor;
increase in fuel consumption.

Note also that in such a situation the car accelerates poorly. When you press the accelerator pedal, jerks, dips, and delays appear. The car jerks a lot, especially in transition modes. The power plant does not so much work as “sneeze.”

Conclusion

At the end, it is worth summing up all of the above. Firstly, popping noises in the muffler are a non-critical problem, but quite unpleasant, and it’s worth addressing it as quickly as possible. Secondly, in addition to external sound factors, there are also internal ones, which lie in the fact that the engine and gas exhaust systems will deteriorate. In addition, slamming means excessive consumption of fuel, which means an increase in the cost of purchasing it. When a car is used for a long time with such a problem, certain parts may burn out, which will completely disable the car and require more money and time for repairs. Popping noises in the muffler on an injection engine may not be eliminated without diagnostics.

What to do if the engine shoots into the carburetor and muffler

The appearance of popping noises in the muffler and carburetor is usually accompanied by a whole list of other symptoms:

the engine “shoots” and does not start;
work at XX is extremely unstable;
the engine loses power and does not “pull”;
the motor is prone to overheating;
fuel consumption increases noticeably;

In this case, the unit’s response to pressing the gas pedal is not clear; delays and dips appear; the machine may jerk under load and in transient modes. In the language of ordinary car enthusiasts, the engine begins to “sneeze.” If the carburetor shoots when starting the engine, and the additional symptoms described above are also present, then certain elements and settings should be checked.

Diagnostics of the ignition system and OZ settings

The check should begin with the high-voltage wires of the ignition system. Violating the order of their connection will lead to the fact that the moment of spark formation on the spark plug will not occur at the end of the compression stroke, and the very order of supplying sparks to the cylinders during engine operation will also be disrupted. In this case, the engine may start, but during operation there will be shooting in the carburetor, which will be repeated at certain intervals. To solve the problem, you should connect the wires to the spark plugs, taking into account the fact that there are special marks on the distributor cover. These labels will help you make connections in the correct order.

If the engine shoots into the carburetor, the reason may be early ignition. This means that the spark appears too early. In other words, the mixture does not ignite at the end of the compression stroke, but at the moment the piston begins to approach TDC, completing the stroke.

In this case, the mixture of fuel and air in the cylinder burns untimely, as a result of which the combustion process is disrupted. The result of early combustion is a “lumbago” in the form of a pop in the carburetor. With late ignition, popping noises can go into the muffler, since combustion is still ongoing when the intake valve begins to reopen on the next stroke. Moreover, the combustion of the remaining mixture also extends to a new portion of the fuel charge, which is sucked into the engine from the carburetor into the intake manifold during intake. Under such conditions of disrupted combustion, the engine overheats. Often late or early ignition can be determined by the condition of the spark plugs. If the spark plugs are white, with carbon deposits, etc., then the OZ needs to be checked and set by adjusting the ignition timing. This adjustment is made by turning the distributor in accordance with the scale.

You should also check the Hall sensor and pay attention to the ignition distributor bearing. Problems with bearing fastening or other nuances may indicate the need to replace the distributor. Let us add that during diagnostics it is optimal to install an initially serviceable device on the car, which will allow faster and more accurate localization of faults in the ignition distributor. Similar actions should be performed with the ignition system switch. If it breaks down, sparking is disrupted and the spark itself is not supplied at exactly the specified moment.

Lean mixture: carburetor and fuel system

Running a carburetor engine on a “poor” fuel-air mixture often leads to the formation of pops and shooting in the carburetor. This phenomenon occurs because the lean mixture burns too slowly. The problem resembles an ignition failure, that is, the lean mixture burns after a new intake stroke has begun. It turns out that after exhaust, the intake valve opens on the intake stroke, and the lean fuel mixture still burns out in the combustion chamber. The incoming portion of the mixture also lights up. As a result, cotton is created in the intake, which reaches the mixing chamber of the carburetor itself. It should also be remembered that a lean working mixture is one of the main reasons for engine overheating.

It is also necessary to check at what level the fuel is in the float chamber. Another reason for a lean mixture may be air leaks. At the same time, you should check the carburetor accelerator pump, especially if shooting occurs when you press the accelerator sharply. Note that in most cases, to normalize the operation of the internal combustion engine, it is enough to clean the carburetor with a “carbicleaner” type cleaner and then correctly configure the device, as well as replace the fuel filters.

Timing faults

Special attention will be required in the case where, after carrying out any repair work or as a result of wear of the timing drive elements, shots appear in the carburetor. The most common cause is a stretched, worn or incorrectly installed timing belt. In other words, a phase failure occurred during the operation of the gas distribution mechanism, as a result of which the fuel mixture burns when the intake valves open. In such a situation, you need to accurately align the timing belt according to the marks.

Such a loose fit of the valves to the seats leads to the mixture burning out in the intake manifold and causing shooting in the carburetor. Operating the engine with the valves clamped after a short period of time causes the valve to burn out, since the edges of the plates experience severe temperature loads, the valves do not release excess heat to the cylinder head, etc. The thermal clearances of the valves must be precisely adjusted, and the settings themselves must be checked every 20-40 thousand km. mileage

Finally, let’s add that popping noises in the carburetor can be caused by a burnt-out valve, as well as other defects in the valve mechanism. In this case, the combustion chamber loses its tightness, that is, the valve plate does not completely adhere to the seat in the cylinder head. After the mixture ignites, a breakthrough of hot gases and flame occurs, and the carburetor begins to fire. To accurately determine the condition of the engine, it is necessary to measure the compression in the cylinders. Based on the results obtained and by analyzing other signs of malfunction, a decision should be made as to whether it is advisable to remove the cylinder head for repair.

What's the result?

It is quite obvious that the appearance of popping noises in the carburetor is an alarming symptom that requires immediate identification and elimination of the existing problem. Let us add that shots or pops can quickly damage the carburetor itself, so further operation of the car is not recommended.

Retarded ignition

Ignition settings if incorrectly configured can easily lead to similar problems. The system should be checked from the ignition timing angle - if it is delayed, then shots through the muffler cannot be avoided. The spark is delayed, causing some fuel to be sent to the manifold. As a result, you can get not only noise effects, but also valve combustion.

But why does it shoot at the muffler if the ignition settings are set correctly? In this case, the problem should be looked for in electrical engineering. Either the spark itself has a weak charge and the ignition of the combustible mass simply does not work, or there are faults in the contacts with the connection of the toggle switch. Problems are eliminated by a complete revision of the ignition system with a possible replacement of the contact group. At the same time, it doesn’t hurt to check the spark plug to see if it matches the engine’s heat rating and whether it’s in working condition in principle.

Popping sounds in the ZIL-130 carburetor - reasons

The truck is equipped with a V-shaped gasoline engine. The reasons that the ZIL-130 power plant shoots into the carburetor are the same as for other engines with a carburetor-type fuel system.

If there are problems with the gas distribution mechanism, it is necessary to determine in which of the cylinder heads there are problems in the operation of the valve system. To do this, you need to measure the compression in each cylinder. A sharp drop in indicators in one of them indicates incomplete closure of the valves.

There are a number of reasons why an engine shoots into the carburetor. They are associated with improper operation of the fuel supply system, ignition and gas distribution mechanism. The motorist can independently identify and eliminate the malfunction.

Have you ever experienced situations in your car where the engine shoots into the carburetor? At what engine speed did the malfunction occur? What caused the popping noise?

We also suggest watching thematic videos below.

Shooting at the carburetor and muffler:

Pops in the carburetor and muffler, failures - how I solved the problem:

You can read about the main causes of engine tripping and their solutions at the link.

The starter screams, the cord comes out

- May scream if there is a lot of lube on the balls. It is necessary to clean the balls and the places in the ratchet where they are inserted.

The cultivator released several pops and began to “float”

- Most likely, the power system is not coping, or the fuel level in the tank is low, the float axis may be skewed and perhaps there is debris under the needle valve, you need to remove everything and check the air filter, jets.

The material will be updated, we will be waiting for questions, stories about the detection of a particular malfunction and ways to eliminate it. Also see Answers to questions about a particular walk-behind tractor model on its description page.

Is your engine running but emitting white or blue smoke? Learn what can cause white smoke in your engine and how to fix it.

CAREFULLY

! Always read the engine and equipment manual(s) before starting, operating, or servicing the engine or equipment to avoid personal injury or property damage. See your authorized dealer or contact Briggs & Stratton if you are unsure of any procedure or have additional questions. Find all engine hazard warnings

Why does the motorcycle muffler shoot?

The essence of the problem

Most often, loud pops in the muffler of two-wheeled vehicles are heard when a lean mixture is supplied to the engine. The reason for its formation may be the use of low-quality gasoline, saturated with water and non-flammable impurities, or incorrect adjustment of the intake system. The air-fuel mixture burns only partially - its remains splash out into the hot muffler, where they explode with sharp, unpleasant sounds. A symptom of a lean mixture is popping sounds in bursts, which intensify as the speed increases.

In powerful motorcycles, the completely opposite problem is more common, associated with the supply of an excessively rich mixture. There is not enough oxygen for its combustion, which leads to the deposition of gasoline condensate on the walls of the muffler. When the “critical mass” is reached, the fuel outside the engine ignites, resulting in one loud bang. If the problem is not corrected, within 1–2 months the contents of the muffler will simply burn out and it will turn into a “direct flow”.

Incomplete combustion of the mixture may be caused by a malfunction of the ignition system. In the absence of a spark, the cylinder misses a power stroke and the full amount of gasoline enters the muffler. Loud sounds are most often heard in this case at high speeds. The problem is also fraught with complete burnout of the muffler from the inside. Misfires are often accompanied by beautiful visual effects - when the engine is overloaded, jets of flame fly out of the exhaust pipes.

Another option is a lean mixture in the intake system caused by air, dirt or water getting into it. Naturally, the fuel does not burn completely and drops of gasoline form on the walls of the muffler, burning with a sharp, characteristic sound. In any case, the motorcycle malfunction must be repaired as soon as possible so as not to encounter more serious repairs.

Reason and solution

The easiest way to get rid of pops on a carburetor motorcycle is to simply move the needle valve to a different position, changing the degree of saturation of the mixture with gasoline. It is better to entrust this operation to a specialist, since not everyone can fine-tune the carburetor. If there is electronic fuel injection, it is impossible to change the gasoline supply parameters yourself - the control unit will have to be flashed at a specialized service station.

It happens that the motorcycle shoots into the muffler and carburetor - this is often found on domestic Urals and imported choppers with a large cylinder capacity. The problem is a clogged air-fuel mixture at the inlet. To eliminate it, it is worth changing the filters and sealing gaskets, and also checking how tightly the pipes fit to the inlet fittings and whether there are any large cracks in them.

Very often, popping noises appear after replacing the muffler with a non-standard one or cutting holes in it to eliminate resistance to escaping exhaust gases. Particularly unpleasant sounds appear when installing a “direct flow”. The reason is the creation of a strong vacuum, which leads to a lean air-fuel mixture. Powerful imported motorcycles often use an exhaust gas afterburning system, which reduces their toxicity - after removing the standard muffler, its operation becomes clearly audible. To eliminate shots after changing the silencer, you must:

Reconfigure the carburetor or reflash the control unit;
Install filters with a different capacity;
Disable the exhaust gas afterburning system.

On sports motorcycles whose engines run at high speeds, the problem with shots may be related to the speed limiter or crankshaft speed limiter. When a certain indicator is reached, the fuel supply may remain unchanged for some time, while the number of flares is reduced. Accordingly, a huge amount of gasoline enters the muffler, which explodes with a jerky sound, forming a “machine gun burst.” It can be heard especially well when releasing the gas after active acceleration. It is impossible to eliminate such a problem without reducing the life of the engine - you have to change your driving style so as not to irritate yourself and others with unpleasant loud bangs.

It is worth paying attention to the ignition system - missed flashes may be due to its malfunction. Carefully inspect the high-voltage wires - there should be no cracks or peeling of the insulation on them. After unscrewing the spark plugs, check to see if there is a specific deposit on their surface that appears when using low-quality gasoline or when the ignition timing is set incorrectly. If the motorcycle is equipped with an electronic ignition system, the problem can often be solved by reprogramming the control unit. Some motorcycle owners decide to make drastic changes by installing a new control unit with preset sport settings - this solves the problem of shots in the muffler, and also increases engine power and improves dynamic characteristics.

Quick diagnostics

Since in the future the problem of popping noises in the muffler can lead to breakdown of the engine and other important components of the motorcycle, it needs to be solved as quickly as possible. You should consistently check the performance of systems such as: intake, ignition, exhaust. All damaged parts are replaced with new ones, connections are sealed. It is also better to temporarily replace tuning components with “stock” ones to check how the engine will perform with factory settings. If all else fails, the motorcycle should be inspected by a professional mechanic, who will find the cause and tell you how to eliminate it at minimal cost and without reducing the life of the power unit.

Popping sounds due to a problem with the ignition system

Popping noises in the muffler at idle or during normal operation can also be heard due to the fact that the ignition system was incorrectly configured. Most often, popping noises at idle, as well as at high speeds, are due to the fact that the ignition is too late. This is explained as follows. The moment the spark appears occurs when the supply valve has already fully opened. Because of this, some of the fuel manages to leak into the manifold, from where it flows into the exhaust system. If the ignition is, for example, too early, then there will still be “shots”, but they will occur in the air filter, and not in the exhaust pipe. In addition, popping noises in the muffler when pressing the gas, if they occur due to late ignition, are also dangerous because the intake valve may burn out over time. For these two reasons, it is necessary to repair such a breakdown very quickly.

Another reason that lies in the ignition system is spark plugs. The spark may be too weak, causing the fuel to not burn completely again. This may happen for the following reasons:

There may be poor contact on high-voltage wires. To exclude this, firstly, you need to check, and, secondly, clean if necessary. In addition, you should check for the absence of such a defect as penetration to ground.
Another reason is a malfunction in the operation of a part such as a distributor. It should be checked anyway.
The spark plugs themselves can fail. If this happens to at least one of them, then this will greatly affect the power of the spark that it produces, and therefore the combustion of fuel.

If the cause of the popping noise in the muffler was precisely the faulty spark plugs, then they need to be replaced, but only with those that have a suitable heat rating. Only in this case will the necessary power be provided to create a spark.

What to do if the engine shoots into the carburetor and muffler

The appearance of popping noises in the muffler and carburetor is usually accompanied by a whole list of other symptoms:

the engine “shoots” and does not start;
work at XX is extremely unstable;
the engine loses power and does not “pull”;
the motor is prone to overheating;
fuel consumption increases noticeably;

Diagnostics of the ignition system and OZ settings

We also recommend reading the article on how to determine early or late ignition yourself. From this article you will learn about the main signs and symptoms of a broken ignition timing.

Another reason why the carburetor shoots may be a faulty distributor (broken ignition distributor). This device may have a number of problems in the form of a breakdown of the distributor cover, a failed slider or high-voltage wires at the place of their attachment.

Lean mixture: carburetor and fuel system

There are several reasons for the formation of a too “lean” mixture: carburetor, fuel lines and fuel filters, fuel pump. The most common carburetor problems can be considered contamination of the fuel and air jets, which are components of such metering devices.

Timing faults

Incorrect valve clearances (the thermal gap between the pushrod and the camshaft cam) are a common cause of carburetor popping. It is a mistake to believe that in order to reduce the noise level of the engine during operation, as well as to reduce the knocking of valves “cold” and “hot”, the specified gap should be reduced. The engine runs quieter at the initial stage, but as a result the valves are “pinched”, that is, they stop closing normally.

What's the result?

If simple methods, such as cleaning the carburetor, adjusting the OZ, replacing high-voltage wires and fuel filters, do not help, then it is necessary to check the timing, measure the compression in the engine and evaluate the overall serviceability of the valve mechanism.

Timing problems

Popping sounds in a muffler whose engine operates with a faulty gas distribution mechanism (GRM) are inevitable. As for the problems that precede timing failure and further firing, they are somewhat similar to those that occur with an incorrectly configured ignition system.

In other words, the exhaust valve will open at a time when the gasoline has not yet completely burned. Naturally, unburned fuel will flow into the exhaust gas system, which will lead to the already familiar pops.

There are several reasons that can occur in the timing system, leading to the following consequences:

A fairly common and first thing to check is timing belt wear. This problem can be identified by additional metallic popping or increased noise when the engine is running at low speed. If this happens, there are two options for troubleshooting. The first is to completely replace the belt, the second is to tighten it if it is loose but not worn out.
It happens that when checking the timing system, wear of the toothed pulley is detected. It will not be possible to repair it in any way, and therefore you just need to replace it with a new one.
Another reason is partial failure of the valves. Over time, they become covered with soot. This process is significantly accelerated if you fill the car with low-quality fuel. Naturally, this will lead to a decrease in the efficiency of the mechanism. The valve springs may become stuck, causing the engine to overheat. They need to be replaced if this happens. It may also be that scratches are found on the surface of the valves, which means they need to be sanded. If there are bends or roughness on the surface, grinding needs to be done.

It is also worth mentioning that popping noises in the muffler of VAZ cars and others that use a timing belt for operation are heard only when the engine is warm. If it's cold, there won't be any. This is also one of the proofs that the problem lies in the gas distribution mechanism.

Quick diagnostics

Timing phase violation

If the engine starts firing at the muffler, this may be the result of a failure of the gas distribution phases. The same situation will arise in the combustion chamber as with an ignition delay: the intake valve will open before the combustion of the fuel. The remaining gasoline will burn out inside the exhaust pipe, which will cause shots.

This can also be caused by stretching the timing belt. The phases themselves do not go astray; if the mechanism uses a belt drive, then most likely the reason is the belt stretching.

Does the muffler pop only when the engine is warm, but not when the engine is cold? The problem definitely lies in the timing belt.