The Chainsaw Does Not Develop Speed And Stalls
Why the chainsaw starts up and immediately stalls
The chainsaw starts up and immediately stalls, the reason for this behavior may be hidden in the carburetor. A malfunctioning fuel pump or malfunctioning of the main fuel jet can cause this saw to behave. The inability to operate the chainsaw after starting, requires a full diagnosis at the service center.
All of the above options for engine malfunction have similar causes, which, depending on their neglect, can have different manifestations. For example, with a slight intake of air into the engine crankcase, its operation will not change much, the engine power will drop slightly, its maximum speed will increase, and it will be able to heat up a little more. In the middle stages of air leakage, the engine will stop idling and will get very hot during operation. Strong air leakage will make it impossible for the saw to work, it will start and immediately stall.
In parallel to the visible manifestations of malfunctions, for example, the inoperability of the chainsaw after starting, processes will take place inside the engine at the time of its malfunctioning, which irreversibly lead the saw to the most serious consequences, for example, the piston melting, the crankshaft jamming.
Why does a chainsaw stall when heated
The situation in which a chainsaw starts up cold, and in the process of heating it can stall, is familiar to many who deal with them. The main reasons for this behavior of the saw are as follows.
- Defective ignition module (coil). Determine the malfunction by checking the spark first on a cold engine, and then on a hot one. If there is no spark on a hot engine, then it is worth trying to fix the malfunction by replacing the ignition coil.
- The carburetor of the chainsaw has an incorrect setting (fills a hot candle). You can determine the problem by how the saw is started on a cold one. If for a cold start it is not required to close the air damper, and the engine starts without a preliminary flash, then the fuel mixture is formed incorrectly and after the engine warms up, the fuel fills the spark plug and makes it impossible to start. The problem is eliminated by adjusting the carburetor.
- Spark plug defective. In such a situation, similar to a faulty ignition coil, the spark disappears when the engine heats up. It is worth trying to replace the spark plug with a new one, and if this does not help, then you need to check the ignition coil and the gap between it and the flywheel.
Why the chainsaw doesn’t pick up speed and stalls
If the chainsaw is unable to pick up speed a minute after starting or stalls when the gas trigger is pressed, most likely the carburetor or crankcase is leaking. As in the previous case, the problem can be solved by checking for leaks and adjusting the carburetor.
If the chainsaw does not pick up speed and stalls after it has been running normally for about 5 minutes, the reason may be a defective fuel tank breather. The vacuum created in the fuel tank during tool operation prevents the engine from receiving the necessary amount of fuel for its normal operation, and for this reason it will be unable to accelerate or stall. In this case, if you stop the tool, open and close the fuel tank cap and start the chainsaw again, the tool will work normally again for about five minutes, after which it will stop gaining speed or stall.
The reason that the chainsaw is not picking up speed can also be excessive carbon deposits in the muffler, which makes it difficult to exhaust exhaust gases, thereby reducing the power and engine speed.
If you want to check the tightness of the crankcase, but there is no special tool, you can use the following test procedure.
The chainsaw starts and stalls cause
Chainsaw owners sometimes have to deal with the fact that the saw, for no apparent reason, stops working normally. To understand why the chainsaw stalls under various operating modes, and also to describe how you can diagnose a malfunction, we will try in our article.
Algorithm for checking the crankcase for leaks
- Remove the side cover and tire from the chainsaw.
- Unscrew the spark plug and put a lace with knots into the cylinder through the spark plug hole, thereby stopping the movement of the piston and crankshaft.
- As a lace with knots, you can use the old cord from the starter, tying knots on it every 3-5 cm.
- Spin the chain saw drive sprocket.
- Remove the oil pump cover and the pump itself.
- Remove the starter from the chainsaw.
- Unscrew and remove the flywheel.
- Remove carburetor.
- Using a syringe, through the hole for the carburetor in the cylinder, pour gasoline into the crankcase, while observing the crankshaft oil seals. If gasoline flows through them, then the oil seals have become unusable and must be replaced with new ones.
- It is better to entrust the installation of oil seals to professionals.
Why does a chainsaw stall under load
In some cases, the chainsaw under load is unable to work normally and simply stalls. A common reason for this behavior is improper carburetor adjustment, or air leaks through the crankshaft oil seals or carburetor gasket. And also this behavior can occur due to leaks in the carburetor.
A saw that is unable to operate under load will also be unsteady at idling. They will “float”. Diagnostics begins with a check for leaks in the crankcase and carburetor. If air leaks through the crankshaft oil seals, they must be replaced. If air leakage in the carburetor is detected, the cause can be eliminated by installing a repair kit of gaskets.
Only after the above actions have not yielded results and the crankcase with the carburetor is sealed, can you start adjusting the carburetor.
The reason for this algorithm is as follows, if the air leak from the crankcase is not eliminated, but the carburetor was simply adjusted to normal engine operation, then the fuel mixture will contain more fuel than is required with a sealed crankcase, which in turn will significantly increase its consumption. Also, most likely, carbon deposits will appear in the engine, which will also negatively affect the further operation of the chainsaw.
In some models of chainsaws, to ensure the operation of the fuel pump, special hoses are installed that transmit an air impulse from the engine crankcase to the carburetor fuel pump. If this hose is frayed, the saw will idle unevenly and will not work at all under load.
, which shows how to replace a defective impulse hose with your own hands on a HUSQVARNA 142 chainsaw, can be seen below. It shows step by step the process of disassembling the saw, shows the impulse hose and stipulates the consequences of its malfunction HUSQVARNA 142.
The chainsaw stalls immediately
What to do if the chainsaw stalls immediately after starting? First you need to check the presence of fuel in the gas tank. If its level is not enough, then you need to prepare the fuel mixture in exact accordance with the ratio of gasoline and oil prescribed in the operating instructions. Gasoline must have the highest possible octane number, and the required brand of oil, as a rule, is indicated in the data sheet of the chainsaw.
Next, we check the spark plug, as well as the contact of its tip with the high-voltage wire. The gap between them should be no more than 0.5 mm. If necessary, the candle is cleaned of carbon deposits and dried. It is recommended to occasionally change the candle to a completely new one. The reasons for the tool stalling when you press the gas lie in the fuel filter or carburetor jet. Cleaning the gas filter will not take much time and effort, but it is better to entrust the disassembly and cleaning of the carburetor to the specialists of the service center.
Chainsaw stalls when tilted
When the chainsaw is in a horizontal position, the fuel pipe lies at the bottom of the gas tank, but when the tool is tilted, the pipe is above the fuel mixture, i.E. In the air. This is what causes the chainsaw to stall on its side.
Chainsaw stalls under load
If the chainsaw stalls under load, the fuel system or a dirty air filter may be the cause. Replacing the fuel with the correct gasoline / oil ratio or cleaning the air filter are universal solutions. An improperly prepared mixture of low-quality gasoline and, for example, engine oil is the main reason for the malfunctioning of a chainsaw, including in the case when it heats up and stalls.
Chainsaw stalls at idle speed
Cases are common when the chainsaw stalls at idle. First of all, you need to check the muffler, and, in case of contamination, clean it from exhaust tar deposits. Also on the carburetors of some models and others there are bolts with the inscriptions H and L. Respectively, rough and fine tuning. By adjusting the bolt L during the operation of the chainsaw so that its speed increases (turn the bolt only half a turn), it is possible to eliminate this problem. Adjusting the carburetor requires an electronic tachometer and is a rather time-consuming process. That is why, in such cases, it is better to turn to professionals.
The chainsaw starts and stalls. Why?
There are several simple rules for the operation and maintenance of a chainsaw, the observance of which will maximize its service life. Preparing the correct fuel mixture, regularly cleaning filters and periodically replacing parts will save you from having to repair your tool for a long time. If it was not possible to avoid the breakdown, then you can figure out its cause completely independently. This applies to all brands of chainsaws, from the more complex Husqvarna and Stihl models to the simplest Makita and Patriot models.
The chainsaw stalls at high speeds
In the event that the tool stalls at high rpm, there are three parts to check: the air filter, the fuel pump and the gasoline filter. The air filter must be cleaned, you can even wash it under water and dry it thoroughly. Then it is enough to disconnect the fuel hose from the carburetor and see if fuel flows out of it or not. If it flows with a full stream, the petrol filter need not be checked. If, on the contrary, the fault has been found. The breather can be cleaned with a regular needle, and the filter can be carefully disconnected from the suction hose, cleaned or replaced with a new one. The gasoline pump is checked for wear: if the fuel does not seep through it, then everything is fine with it. If the problem that your tool stalls at full speed is due to some damage to the pump, then this part just needs to be replaced with a new one.
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Malfunction of the cylinder-piston group
As a result of scuffing on the piston walls, the considered speed problem may arise. Seizures can usually be found on the muffler side. As a rule, this breakdown is solved by replacing the CPG, the cost of which can be comparable to the price of the saw itself.
Replacement of hoses, oil seals, gaskets is required
Any plastic and rubber elements deteriorate over time. If the saw works on XX, and when you try to increase the speed either does not gain them, or does it very weakly (well, or stalls), you need to check the hoses and seals for integrity. Hose problems are usually detected simply by inspection, but the loss of tightness of the seals can be found out in most cases only by supplying air under pressure.
A shim problem is usually found immediately or shortly after a saw is repaired. If you or someone has recently disassembled the unit, after which the described problems arose for no apparent reason, you need to check the quality and correct installation of the gaskets.
Adjusting the carburetor when the engine stalls while accelerating
If the check showed that the fuel supply system, muffler and spark plug are in good working order, then you need to look for a breakdown in other places. Initially, do not rush to disassemble the cylinder-piston group or change the carburetor. It is recommended to start repairs by adjusting the carburetor. For this, all chainsaws have special adjusting screws. They are designed to adjust the idle speed, as well as adjust the fuel supply at low and high speeds. A detailed description of how to adjust the carburetor of a chainsaw is described on the website.
Today we will consider the features of tuning the carburetor at maximum speed. You can make sure that the chainsaw does not develop full power using a tachometer. If there is no device, then you can make sure that the engine does not develop maximum speed by ear. We are interested in the screw on the carburetor. Which is designed to tune high rpm. It is usually denoted by the Latin letter “H”, which is abbreviated from the word “High” (high or large).
To adjust the high speed of the chainsaw, you will need to perform the following manipulations:
- Tighten screw H clockwise until it stops.
- Next, you need to loosen it by 1.25-1.5 turns
- Run the tool and test the speed performance
It is recommended that the adjustment be performed using a tachometer, but if it is not there, then you can check the maximum revolutions when using the tool under load.
After trivial tuning the carburetor, you can fix the problem with the termination of the engine when the speed rises. It should be noted that it is necessary to adjust the carburetor of the chainsaw regularly, depending on the frequency of operation of the tool. It is not difficult to do this yourself, but you can achieve accurate tuning in one case. If you use a tachometer.
Where to look for the reason or where to start checking
All chainsaws have the same design and work according to the same principle. The chainsaw device can be found in this material. It does not matter which brand of tool. Stihl, Husqvarna, ECHO, Champion, Partner, Sturm and others. A malfunction that manifests itself in the form when the chainsaw stalls when the gas is pressed can occur equally both on expensive and high-quality tools and on budget Chinese devices. If a problem occurs, then it needs to be solved.
A chainsaw is a system of mechanisms consisting of parts. Any part in the mechanism can fail, which will lead to partial or complete failure of the tool. If the engine of the tool starts, this does not mean that the chainsaw is completely operational. When the engine stops working when the engine speed rises, then there are corresponding reasons. With this malfunction, attention should be paid initially to a number of the following tool mechanisms:
- Gas tank. Make sure there is fuel. If there is sufficient fuel, you should also check the serviceability of the fuel filter, the presence of a connection of the supply hose with the carburetor, and also make sure that the breather is working
These are the main parts and mechanisms that should be checked first if a malfunction occurs when the chainsaw stalls when the accelerator is pressed. There are other reasons why the chainsaw engine stalls when the gas trigger is pulled. What else can contribute to the occurrence of this malfunction, as well as the features of eliminating breakdowns, we will find out further.
In the event that the saw does not receive enough air or fuel, naturally, it will stall when trying to increase the speed or even just at idle speed. The filter contamination is checked purely visually. Filters need to be changed if dirt problems are suspected.
Why the chainsaw stalls when the accelerator is pressed. Summing up
When making an upgrade for the reasons why the saw stalls after you press the gas, you need to take stock of all sorts of reasons and their elimination. The reasons can be conditionally divided into two parts. Simple and complex. You need to start troubleshooting with simple reasons, and end with more complex ones.
You definitely need to start the check from the tank, not from the carburetor, but from the gas tank. And make sure to use a properly prepared mixture. Next, you need to check the serviceability of the muffler and the presence of carbon deposits on the spark plug. After that, you will already have an idea of in which part of the tool you need to look for a breakdown. Perhaps a breakdown is. That you just need to wind up the maximum speed, for which the carburetor is tuned. If this does not solve the problem, then you should check the air filter and clean it.
Pay special attention to the carburetor, after cleaning and possibly repairing which the chainsaw should work like new. If even after this the problem remains, then do not be too lazy to check the amount of compression. Perhaps the engine has a strong performance and needs to be replaced.
This completes the upgrade to restore the tool’s performance, and it is worth noting one more point, such as the use of fuel that is stored for a long time. Many people dilute gasoline with oil, and store the mixture for months, and sometimes for six months. This cannot be done in any way, since the mixture has the properties of aging, and therefore, after its preparation, it must be used within 1-2 weeks. If you do not follow this recommendation, then you will need to often change not only the fuel filters, but also clean the carburetor, but the worst thing is that this contributes to accelerated wear of the CPG.
The main causes of chainsaw breakdown
Although the chain saw is a simple device, from time to time, problems arise in its operation, which can only be fixed by disassembly. The following malfunctions can be cited as examples:
- The chainsaw is not picking up speed;
- The chainsaw stops functioning in the cut;
- The chainsaw starts and stalls;
- The chainsaw loses its power;
- The chainsaw stalls when pressed.
Most often, malfunctions are associated with interruptions in the functioning of the motor, as well as malfunctions of other systems and components. Proper handling of this technique is essential. When all the rules of use are followed, problems with a high probability lie in the most obvious. When looking for the causes of problems, it is advisable to start by checking the simplest part of the chain saw and finish the most difficult.
Why the chainsaw doesn’t pick up speed and stalls
If the saw cannot gain speed or stalls when you press the gas, then most likely this is caused not by the tightness of the carburetor or motor crankcase. This problem is eliminated by checking for leaks and adjusting the carburetor.
In addition, this malfunction may be associated with a defect in the fuel tank breather. Due to the formation of a vacuum in the fuel tank during the operation of the chain saw, the required volume of the fuel mixture does not enter the engine, as a result of which it cannot gain speed or stalls. If you stop the chain saw, open and close the fuel tank and turn it back on, it will work normally for about five minutes, and then it will stop picking up speed again or stall.
Another possible reason that the chain saw is not able to pick up speed may be excess carbon deposits in the muffler, which makes it difficult for exhaust gases to escape, which reduces the power and engine speed.
What to do if the chainsaw stalls when you press the gas
One of the most common questions regarding the operation of this device: why the chainsaw stalls when you press the gas and what should be done to solve this problem? In such a situation, you need to do the following:
- Check the fuel filter;
- Inspect the fuel hoses for leaks;
- Check the muffler;
- Try to increase the speed a little;
- Check the condition of the rubber seals on the crankshaft.
Why does a chainsaw stall under load
Sometimes the saw will not function properly under load. This is most often caused by improper adjustment or leaking carburetor. In addition, air leaks through the carburetor gasket or crankshaft oil seals may be the cause of this problem. A tool that is unable to function under load also cannot maintain idle speed reliably.
Diagnostics begins with checking the carburetor and crankcase for leaks. If air leaks through the crankshaft oil seals, they must be replaced. If air leaks in the carburetor are detected, a repair kit of gaskets is required to solve the problem.
If these actions did not lead to the desired result and the crankcase of the engine with the carburetor is tight, then you need to adjust the carburetor.
If a Husqvarna chainsaw stalls under load, then in case of any deviations in the functioning of the engine, you should first of all check the impulse hose, since this is the most common cause of breakdown of this brand of chainsaws.
Why does a chainsaw stall when heated
It often happens that the chainsaw starts up cold, but stalls during the heating process. This behavior of the tool can be caused by the following reasons:
- The carburetor is incorrectly set. This problem can be identified by how the device is started up on a cold one. If it is performed without closing the air damper, and the engine starts without a preliminary flash, this means that after heating the engine, the fuel fills the candle. The solution to this problem is to adjust the carburetor. Details on carburetor adjustment
- Coil (ignition module) malfunction. You can identify this problem by sequentially checking the spark, first on a cold and then on a hot motor. If there is no spark on a hot engine, then the ignition coil must be replaced.
- Defective spark plug. In this situation, as in the case of a malfunction of the ignition module, the spark disappears when the engine heats up. It is necessary to replace the spark plug with a new one, and if this does not lead to a solution to the problem, then the ignition module and the distance between it and the flywheel should be checked.
Checking the main systems of the chainsaw
If the chainsaw refuses to work properly, you need to make sure that all the conditions required for its normal operation are provided:
Then it is necessary to sequentially check the functioning of all its elements. First you need to check the fuel tank. If the cause is not volume and quality of fuel, spark plugs are likely to be the cause. The gap at the candle should not exceed 0.5 millimeters. If it is too small, it means that carbon deposits have been deposited on the candles. In this case, remove the candles, clean them, then reinstall and try to start the chainsaw. In addition, it is advisable from time to time to completely replace the candles with new ones, even if they are in good condition.
Then you need to check the condition of the fuel filter and carburetor. Self-cleaning of the fuel filter is a simple task, but it is best to entrust the repair of the carburetor to specialists.