Stihl Chainsaw Stalls When Pressed

A chainsaw is a highly effective tool that is designed to work with wood. However, the high-speed engine of this tool can be used to perform a number of other tasks, which is achieved through special nozzles. Sometimes a malfunction occurs such as a chainsaw stalls when you press the gas, which can be triggered by some factors. In order not to have to disassemble the tool completely, we will consider all possible causes of this problem with a detailed description of how to fix them.

Where to look for the reason or where to start checking

All chainsaws have the same design, and work on the same principle. The device of the chainsaw can be found in this material. It does not matter much what brand of instrument. Stihl, Husqvarna, ECHO, Champion, Partner, Sturm and others. A malfunction, manifested in the form when the chainsaw stalls when you press the gas, can occur equally on expensive and high-quality tools, and on budget Chinese devices. If a problem arose, then it needs to be addressed.

A chainsaw is a system of mechanisms consisting of parts. Any part in the mechanism may fail, which will lead to a partial or complete failure of the tool. If the tool engine starts, this does not mean that the chainsaw is fully operational. When the engine stops working with increasing speed, there are corresponding reasons for this. With this malfunction, attention must first be paid to a number of the following tool mechanisms:

  1. Gas tank. Make sure fuel is available. If there is enough fuel, you should also check the fuel filter for serviceability, the connection of the supply hose to the carburetor, and also make sure that the breather is working

These are the main details and mechanisms that should be checked first of all if a malfunction occurs when the chainsaw stalls when the accelerator is pressed. There are other reasons why the chainsaw engine stalls when you press the gas trigger. What else can contribute to the occurrence of this malfunction, as well as the features of eliminating breakdowns, we will find out further.

Adjustment of the carburetor when the engine stalls at a set of turns

If the check showed that the fuel supply system, muffler and spark plug are working, then you need to look for damage in other places. Initially, do not rush to disassemble the cylinder-piston group or change the carburetor. Repair is recommended to start by adjusting the carburetor. For this, all chainsaws have special adjusting screws. They are designed to adjust the idling, as well as adjust the fuel supply at low and high speeds. A detailed description of how to adjust the chainsaw carburetor is described on the website.

Today, we will consider the features of setting the carburetor at maximum speed. To make sure that the chainsaw does not develop full power, you can use the 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 a carb screw. Which is designed for setting high revs. It is usually denoted by the Latin letter “H”, which is short for the word “High” (tall or large).

To configure high speed chainsaws, you will need to perform the following manipulations:

Stihl Chainsaw Stalls When Pressed
  1. Tighten screw H clockwise
  2. Next you need to loosen it by 1.25-1.5 turns
  3. Run the tool and test the speed

Adjustment is recommended to be performed by the tachometer, but if it is not there, then you can check the maximum speed when working with the tool under load.

After the banal carburetor tuning, you can fix the problem with the engine stopping when increasing the speed. It should be noted that it is necessary to adjust the chainsaw carburetor regularly depending on the frequency of operation of the tool. Doing it yourself is not difficult, but you can achieve fine tuning in one case. If you use a tachometer.

Why else can a chainsaw stall when I press the gas

If the problem remains after setting the carburetor of the chainsaw, then you should resort to checking a number of other factors. There are enough such factors, and their verification must be carried out sequentially, moving from easier to more complex. It is in this order that we consider all the reasons why the chainsaw does not develop high speeds, and at the same time stalls. It should be noted that at the same time the tool starts up and at idle it works properly.

  1. Check the tension of the chain. If the cutting element is tightened tightly, this will create a heavy load on the engine. In this case, it will be difficult for a high-speed engine to scroll the chain, as a result of which we get its cessation of work. You can fix the problem if you correctly adjust the chain tension. The chain should rotate easily by hand, but also keep in mind that it should not be moved to XX. If the chain idles, you need to adjust the top screw XX
  2. The quality of the fuel mixture and the correctness of its preparation. Gasoline for a chainsaw is recommended to use the AI-92 brand. It is mixed with push-pull oil in appropriate proportions. Mixing proportions, although indicated on the label of the container with oil, but you must use the data indicated by the manufacturer of the tool. The optimal value of a mixture of gasoline with oil is 40/1, that is, 25 ml of oil should be added per 1 liter of gasoline. Proportion means that for 40 liters of gasoline you need to add 1 liter of oil. If you do not adhere to the manufacturer’s recommendations, then in the end it negatively affects the work of the carburetor and the health of the CPG
  3. Silencer. Very often sawyers do not pay due attention to the exhaust system of the instrument. If the silencer is clogged, and this necessarily happens over time, this negatively affects the operation of the motor. Silencers on chainsaws are collapsible and non-collapsible. For non-separable devices, the connections are rolled, so in case of clogging, you must either replace the part or flare for cleaning. A clogged silencer affects the operation of the tool, so do not wait until the chainsaw stops starting
  4. Air leakage. Parts and mechanisms of the chainsaw are connected to the cylinder through gaskets. As a result, such compounds are sealed, which is important for the operation of the internal combustion engine. To make sure of such a malfunction, tightening the bolts and nuts that secure the carburetor and muffler will help. Leakage can also occur due to deterioration of the gaskets, which should be replaced on the tool
  5. Fuel and air filters are the elements responsible for filtering air and fuel mixture. If the air filter is clogged, then with an increase in the opening of the flap, a sufficient amount of air will not enter the carburetor, which will lead to the filling of the spark plug. As a result, the engine stalls when trying to develop maximum speed. If the fuel filter is faulty, then the required amount of fuel does not get into the carburetor. Its lack leads to the fact that the tool cannot develop revolutions, and immediately begins to stall
  6. The presence of a fuel filter. This element can not only become clogged, but also disconnect from the fuel hose. As a result, it turns out that pollution will get into the carburetor, which will very quickly disable the mechanism
  7. A breather is a hole through which air enters the chainsaw tank, thereby eliminating the creation of a vacuum inside an airtight container. The breather is located on the lid of the gas tank or may be built into the wall of the tank. The principle of its operation is such that, as gasoline is used up in the tank, the tank is filled with air. If the breather is defective, a vacuum is created in the tank, which prevents the fuel from pumping into the carburetor. The breather passes air in one direction, and eliminates the possibility of leakage of fuel from the tank. You can repair the part with a thin needle, with which a hole is made
  8. Malfunction of the CPG. The chainsaw does not gain momentum also if the cylinder-piston group is worn. To identify this reason, there is no need at all to disassemble the engine in order to look inside. A compressor should be used to check the amount of compression. The normal value must be at least 12 atmospheres, and if the value is lower, then the CPG must be replaced
  9. Ignition system. If the engine starts, it is unlikely that the problem is a malfunction of the electrical part. However, it will not be superfluous to unscrew the spark plug, and make its visual inspection. The presence of black soot indicates the need to check the ignition. First of all, you need to check the gap between the ignition module and the flywheel, the value of which should be 0.25 mm. The integrity of the armored wire is also checked, and if it is damaged, it must be replaced with the module. Spark plugs have an appropriate resource, therefore they need to be changed, previously setting a gap of 0.5-0.7 mm (indicated in the technical description for each model of tool)

If checking all the reasons does not allow to achieve a positive result, then you should remove and clean the chainsaw carburetor.

Chainsaw stalls at high speeds. Simple carburetor repair

The carburetor of the instrument is exactly the mechanism that most owners are afraid to disassemble on their own. The reason is that this mechanism consists of many small parts, the location of which must be remembered during the dismantling work. However, not everything is as scary and difficult as it may seem. To understand what the carburetor has to do with the problem of engine shutdown with increasing speed, you need to find out its operating principle, described on the site.

The chainsaw stalls when you press the gas due to the carburetor, if:

  1. Damaged membrane
  2. Clogged filter element (mesh in carburetor). Owners of tools that do not have a fuel filter or are simply disconnected from the fuel hose may encounter this malfunction.
  3. Sticking of the needle, which may be due to the use of outdated fuel mixture
  4. Clogged nozzle channels or clogged carburetor
  5. Bending of the connecting part connecting the membrane with the needle for supplying fuel to the carburetor fuel chamber. This part is also called the foot, since under the influence of the membrane on it, the needle moves and the channel opens. This foot can bend (develop) or break during operation (the engine will not start when it is broken). If the foot is bent, it can be bent, but this does not guarantee that the problem will recur soon, so it is recommended to replace the part

It is recommended to clean and wash the chainsaw carburetor, as well as replace defective parts and components. After that, it can be put back, without forgetting to also replace (if worn) the gasket between the carburetor and the adapter.

Why the chainsaw stalls when you press the accelerator. Summarize

When upgrading for reasons why the saw stalls after you press the gas, it is necessary to summarize all sorts of reasons and eliminate them. 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.

Definitely, you need to start the test from the tank, not from the carburetor, namely from the gas tank. And make sure that you use the correctly prepared mixture. Next, you need to check the muffler and the presence of carbon deposits on the spark plug. After that, there will already be an idea of ​​which part of the tool you need to look for a breakdown. Perhaps a breakdown in that. What you need to simply wind up the maximum speed, for which the carburetor is set up. If this does not solve the problem, then check the air filter and clean it.

Pay special attention to the carburetor, after cleaning and possibly repairing it, the chainsaw should work like new. If even after this the problem remains, then take the time to check the amount of compression. Perhaps the engine has a strong output, and needs to be replaced.

At this point, the upgrade to restore the instrument’s performance has been completed, and it is worth noting another such point as the use of fuel, which is stored for a long time. Many dilute gasoline with oil, and store the mixture for months, and sometimes for six months. You can’t do this in any way, since the mixture has the properties to age, and therefore, after its preparation, it must be used within 1-2 weeks. If you do not follow this recommendation, you will often need to change not only the fuel filters, but also clean the carburetor, but the worst thing is that this contributes to the accelerated wear of the CPG.