Chainsaw stalls at idle cause

Does not idle the chainsaw

The serviceability and efficiency of household and professional chainsaws largely depend on the degree of wear of their main operating mechanisms. Several factors indicate damage to the working units of the gasoline tool, the main of which is the speed of the running engine. Their arbitrary growth or decrease can prompt the operator about a breakdown of the carburetor, violation of the clutch clearance and other malfunctions. this will make it possible to identify any of the breakdowns in time and eliminate it on their own.

What to do if the chainsaw is gaining momentum by itself?

This malfunction is typical for novice gardeners who ignore the need for timely maintenance of their gasoline-powered tools. In the case of an arbitrary set of revolutions with a chainsaw, the cause must be sought in the carburetor. First of all, it will need to be completely disassembled. After making sure that all the built-in parts are in good working order, you can start flushing the fuel unit. For this you need:

  • place all carburetor elements in a container with clean gasoline. After knocking, the parts must be removed, rinsed thoroughly with water and dried;
  • the fuel pipes must be blown out with compressed air from a cylinder. Immediately before re-installing the hoses at the points of their connection to the fittings, you will need to apply silicone sealant;
  • after installing the carburetor, not the chainsaw, you need to re-adjust it. Before that, you need to make sure that the power unit is in good condition, as well as the filters, rubber gaskets and bushings are in working order.

In some cases, the cause of an arbitrary set of revolutions with a chainsaw may be a loss of sealing of the crankshaft oil seal. Due to constant contact with the moving shaft, the stuffing box lends itself to increased heating, which leads to the formation of cracks and holes inside it. A damaged gasket cannot be repaired, so it must be replaced.

Often, the cause of air leakage, due to which an arbitrary set of revolutions by the motor occurs, is the loss of fixation of the bolted connections. In this case, the operator will need to tighten all the bolts and check the operation of the gas tool again.

The chainsaw does not slow down. how to find and fix a breakdown?

The most common cause of this frequent breakdown is an improperly adjusted damper. It is needed to suck in the air that the carburetor needs to enrich the fuel mixture with air. To adjust the choke, you need to adjust the operation of the carburetor. In this case, special attention should be paid to the operation of the power unit at idle. You can check the operation of the engine in idle mode by paying attention to the state of the circuit immediately after starting the internal combustion engine. If it rotates, then you need to adjust the power unit.

Another reason for this typical malfunction is air leaks. If air leaks in one of the chainsaw mechanisms, the mixture will automatically deplete, which will lead to a spontaneous increase in the speed of the chainsaw motor. In this case, the operator will need to carefully check the entire fuel system, including the carburetor, tubes, and working chambers of the unit.

In some cases, the chainsaw does not decelerate due to a jammed accelerator cable. In this case, the power unit will independently gain momentum to the maximum immediately after it is started. Disassembling the gas handle and inspecting the entire gas supply mechanism will help to solve the problem. A jammed cable will need to be adjusted or completely replaced.

Why the chainsaw isn’t picking up speed?

In cases in which the used gasoline saw is not able to steadily gain momentum and stalls spontaneously when you press the accelerator, you will need to carefully check the engine crankcase and carburetor. First of all, the operator should carefully inspect the assemblies and make sure that they are not sealed. If a large amount of oil was found inside the crankcase or carburetor, then the leak inside the faulty unit must be repaired.

The next reason why the chainsaw does not develop speed. a manufacturing defect or mechanical damage to the breather located inside the fuel tank. A vacuum can form in the fuel tank, which leads to a lack of fuel supply to the working cylinder of the power unit. Deposits that have accumulated on the surface of the fuel cylinder can also cause this problem. In this case, you need to remove the filter element and rinse it in clean gasoline. If after that the chainsaw continues to stall under load. then you need to perform the following procedure: turn off the power unit of the chainsaw, remove the fuel tank cap and tighten it again. If after that the motor of the gasoline-powered tool starts to gain momentum and after 5 minutes of operation it stalls again, then the cause of the breakdown is a faulty breather.

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A thick layer of carbon deposits on the walls of a factory muffler can be another common cause of a saw motor not spinning. Resinous deposits and ash will prevent exhaust gases from escaping, which will lead them back to the engine compartment. As a result, the engine will begin to emit extraneous sounds and severely lose speed even with a slight press on the accelerator.

The chainsaw does not idle. search for reasons and repair

There can be several reasons for this common breakdown. Basically, the loss of speed when the internal combustion engine is idling is associated with engine malfunctions, loss of compression in its standard cylinder, ignition system, carburetor, as well as improperly prepared fuel mixture. In search of the exact cause of a breakdown, the operator may encounter the following problems:

Husqvarna chainsaw won’t stay running.

chainsaw, stalls, idle, cause
  • accumulation of resinous deposits and ash, small debris on the air and fuel filters of the chainsaw. if possible, the elements must be washed. If, in addition to blockages, cracks or holes were found on the surface of the filters, then the foam elements will need to be completely replaced;
  • spark plug defect. cracks, chips or burrs disrupt the work of the part, which leads to a loss of engine speed when it is idling. In this case, the candle will need to be replaced;
  • loss of factory settings of the carburetor. increased pressure on the power unit leads to an increase in its vibration. As a result, the spring-loaded metal bolts of the fuel assembly lose their original position, which leads to a loss of engine speed;
  • cracks and holes in the fuel pipe. to repair the chainsaw, the hose must be replaced;
  • clogging of the inner walls of the muffler. dismantling, thorough flushing and reinstalling the muffler will help solve the problem. If large burrs have formed on the internal cavities of the element, then it will soon begin to rust. To prevent this, it is better to replace the muffler immediately;
  • malfunction of the CPG of the power unit. the appearance of microcracks or burrs on the inner surface of the cylinder and piston will lead to a loss of tightness of the working chambers. As a result, the amount of air required to enrich the fuel mixture will be disrupted. this will result in a loss of engine speed when idling.

What to do if the chainsaw starts and stalls

One of the most popular situations in working with a saw is the moment when the chainsaw starts and stalls. This can happen with both a new and an “experienced” instrument, and there are more than enough reasons. The most common of them is the lack of the required amount of fuel in the gas tank. It doesn’t matter which saw you have, a Chinese Husqvarna or an original STIHL: if there is not enough fuel, then the problem in question follows. So, if there is little fuel, then you need to increase its volume in the tank by preparing the required amount according to the established proportion. How to do this. look in the instructions; the brand of oil that needs to be used is also indicated there. An interesting nuance with gasoline. it must have a maximum octane number, its quality depends on this, respectively, and the work of the saw itself.

For the sake of economy, many users of saws, and most often this happens with domestic brands Ural and Druzhba. they do not drain excess fuel, leaving the saw to “winter” with it for many months. It is strictly forbidden to do this, firstly, for fire safety purposes, and secondly, in order to avoid deliberate provocation of the breakage of your tool. There are other situations when the owners of chainsaws manage to add new fuel to the old fuel, forgetting about the lost qualities and the possible chemical reaction of this “explosive mixture”. This absolutely must not be done.

In addition to fuel, you also need to check the spark plug. Remove excess carbon deposits from it or replace with a new one, check the contact with the high-voltage wire and, with a gap of more than 0.5 mm, carry out a mandatory replacement of the spark plug.

Chainsaw stalls when you press the gas. reasons and solutions

Even an amateur in working with a chainsaw should distinguish two situations of a stalled saw: if the chainsaw stalls when the gas is pressed, then there is insufficient fuel supply, and the load means not only the addition of gas, but also the complication of the work of all other components of the saw that have not previously taken part in overcoming obstacles. Here we mean that the moment when the saw collides with an element that should be cut, that is, a tree. it works at a stronger power than when the gas is pressed normally.

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A stalled saw when adding gas may indicate a dirty fuel filter, which you can clean yourself. If the carburetor jet or its other component does not work, then in this case it is better to send it for repair. If the saw starts and stalls, then the reason may be pouring fuel fluid onto the same spark plug, or an elementary dirty air filter.

Why the chainsaw stalls

There are a lot of situations why a chainsaw stalls. Since it is a technical mechanism, at the slightest deviation it tends to give a reaction through partial or global breakdown. There is a list of the most common malfunctions, the reasons for which we will consider in this article:

Here you can choose others spare parts for chainsaws, we will be happy to answer all questions and suggest possible solutions to problems even in desperate situations with a tool.

Do I need repair if the chainsaw stalls at idle speed??

Everyone knows the situation when, at idle, his tool simply stalls. This happens with almost all devices that have a motor. The main reasons are:

  • idling stalls due to clogging of the air or fuel filter;
  • no spark due to a bad spark plug;
  • Carburetor adjustment, as one of the most important reasons for a stalling saw, can also be the reason that this happens when heated. His substandard work contributes to the fact that the instrument stalls “hot”.

Checking and repairing the carburetor

If checking the ignition system, fuel filters, muffler did not give tangible results, the tool still does not want to work normally at minimum speed, you need to check the carburetor.

To adjust the operating modes, there are three screws on the device case, designed to set the minimum rotation speed, maximum speed and idle speed.

On many models, manufacturers install only the idle adjustment screw to avoid incompetent attempts to adjust the device. In all variants of the device, the adjustment must be carried out exactly according to the recommendations of the manufacturers.

If the adjustment of the device did not lead to the restoration of the normal operation of the tool, it is necessary to completely disassemble the device with an inspection. It should be understood that a carburetor is a rather complex device, in the absence of experience, it is advisable to contact a specialist.

When disassembling, it is important to carefully inspect and flush all jets, air and fuel channels, and filter mesh. Damaged elements must be replaced with new ones. The jets should be cleaned with a soft wire of the appropriate diameter.

It is advisable to carry out the work in appropriate conditions. The carburetor contains many small parts, the loss of any of them will make the device inoperative.

Checking the spark plug and ignition system

According to the manufacturers’ recommendations, the spark plug should be replaced annually, regardless of the intensity of the tool use. Failure to follow these tips leads to a completely natural result: failures at idle speed, subsequent failure.

Typical defects in the ignition system are as follows:

  • The candle was flooded with fuel at the time of start-up. It is necessary to remove it from the nest, dry it, if possible, blow it out with compressed air. Drain the remaining fuel from the cylinder through the mounting hole, blow it out with compressed air. Then install the candle, connect the high-voltage wire, start.
  • No spark on the spark plug electrodes. You need to disconnect the high voltage wire and check for a spark on it. If the spark is normal, check the connection, eliminate any defects. The absence of a spark on the high-voltage wire indicates a malfunction of the ignition unit. This device cannot be repaired, it must be replaced with a new one.
  • The gap between the spark plug electrodes is broken. This parameter for various types of devices can be in the range from 0.2 to 0.5 mm. Checking and adjusting must be carried out using a special dipstick or vernier caliper. The required value can be found in the instruction manual of the tool.
  • The direction of the search can be determined by the appearance of the candle. If the spark plug turns out to be dry after several attempts to start the engine, it means that gasoline is not entering the cylinder. It is necessary to check the fuel supply system and carburetor.
  • The presence of black soot or carbon deposits on the electrodes indicates an incorrect carburetor adjustment or a clogged air filter. Possibly low-quality fuel with large m of oil is being used. During normal operation of the ignition system, the electrodes have a uniform gray color and brown deposits on the insulators.

Muffler inspection and repair

Clogged mufflers should be left to soak in warm water and detergent, then thoroughly wipe and dry.

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A defective muffler will result in a drop in tool power during operation and idle stops. Despite the seeming simplicity of this detail, it is also important to follow it. Quite often the muffler is clogged. During work, wood dust, sawdust, resin particles may get on the grate. High temperatures cause them to adhere and accumulate, and exhaust fumes also form deposits on the surfaces of the spark arrester and other parts. The layer that builds up over time reduces the muffler’s flow capacity and interferes with the normal removal of exhaust gases. The engine, figuratively speaking, suffocates.

Top Reasons Chainsaw Starts, Then Stalls — Chainsaw Troubleshooting

Repair of this unit is not difficult, it is quite within the power of many tool owners. The device should be removed from the engine, the openings should be covered with rags or other material. If the formed layer is too hard, all parts can be left to soak in warm water and detergent. After softening the plaque, the parts should be washed with a rag or soft brush and wiped thoroughly. Inaccessible areas can be blown out with compressed air or dried with a hairdryer. The use of mechanical means of removal is undesirable.

For normal functioning of the muffler over a long period of operation, use the lubricants recommended by the manufacturer, observing their shelf life. The mixture must be prepared immediately before work and consumed completely.

Your Chainsaw Stalls? You Can Fix It, Here’s How

Probable reasons for refusal

The power unit of all chainsaws is a single-cylinder internal combustion engine. For devices of this type, such malfunctions are characteristic as a violation of the inside of the cylinder compression, a change in the ratio of the fuel mixture, incorrect operation of the ignition, and poor-quality fuels and lubricants. The main problems in the operation of the power unit are as follows:

chainsaw, stalls, idle, cause
  • the engine runs stably at minimum speed, but stalls with increasing speed;
  • start-up occurs normally, and idle speed is unstable, stalls quickly;
  • does not start.

Chainsaw electronic ignition circuit.

Abnormal idling can be caused by various reasons. They can be divided into several positions:

  • reduced throughput of filters (gasoline and air);
  • abnormal operation of the ignition system:
  • the carburetor settings have spontaneously changed;
  • malfunction of the elements of the gas line;
  • clogged exhaust ducts, muffler;
  • defects of the piston, cylinder, valves.

Repair should start with an external inspection and checking the presence of fuel in the tank.

What to do if the chainsaw stalls at idle speed

The chainsaw stalls at idle: many owners of this tool face such a problem. By its structure, the saw was a fairly simple tool. But there are times when it fails. The main problem in troubleshooting is determining the correct cause of the abnormal operation. Once the cause has been identified, fixing the defect is usually quite simple.

Filter check and repair

The engine may run intermittently or stall if there is insufficient fuel or air. Causes. clogged air or fuel filter. To check the fuel filter, it is necessary to remove the fuel line hose from the carburetor fitting and direct it to a container. Then press the fuel pump several times. If the fuel is pumped normally, in clearly defined doses, without dirt, then the fuel filter is in good working order. If the jet is weak or the fuel is not pumped at all, the filter must be replaced or, if possible, cleaned.

Clogging of the fuel filter with sawdust is one of the reasons for the breakdown of the chainsaw.

The device must be removed from the fuel tank (after all the fuel has been drained from it). On most models, the fuel filter can be hooked out of the wire through the neck. If the filter design is collapsible and can be cleaned, it must be disassembled and washed in accordance with the manufacturer’s recommendations. Otherwise, change to a new filter.

Similar problems can arise when the air filter is clogged with dust, sawdust, or dirt. If the amount of air is insufficient, the fuel mixture will be enriched, the fuel combustion process is hampered.

To check, remove the filter. When working, you need to take precautions so that dust does not get into the carburetor. The device must be cleaned and rinsed in warm water with the addition of detergent. After drying, if possible, blow out with compressed air of low pressure, reinstall. If the chainsaw works fine, then the cause has been eliminated, if not, you need to look further.

With continuous operation of the tool, it is recommended to replace the filters of the fuel and air systems after 3 months.


Chainsaws, like most tools, require timely maintenance and care.

Failure to comply with this rule leads to tool failure, material costs, loss of precious working time at the most inopportune moments.