Stihl 180 Chainsaw Stalls At Idle

The chainsaw starts and stalls There are several simple rules for the operation and maintenance of the 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. It concerns.

Chainsaw stalls under load

If the chainsaw stalls under load, this may be due to the fuel system or a dirty air filter. Changing the fuel with the correct gasoline / oil ratio or cleaning the air filter are universal solutions to this problem. 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.

The chainsaw starts and stalls. Why?

There are several simple rules for the operation and maintenance of a chainsaw, the observance of which will allow you to 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.

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 just 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 proportion of oil and gasoline for the Stihl 180 chainsaw

To exclude premature breakdown of the carburetor, the factory cylinder-piston group and other important components of the garden tool, it is important to observe the ratio of gasoline to the used engine oil.

First of all, you need to study the proprietary manual. The operating instructions will indicate the correct fuel ratio, the correct gasoline and the correct chain oil for the Stihl 180 chainsaw.

Stihl 180 chainsaw stalls at idle

According to the manual of the German Stihl saw, to refuel it, you need to use only gasoline of a brand not lower than AI-92, as well as branded oil for 2-stroke Stihl engines. The ratio of fuel and oil should be 1:40, that is, add 25 ml to 1 liter of gasoline. Stir the fuel mixture thoroughly by shaking the container several times. After that, the contents of the vessel will need to be poured into the fuel tank.

Do-it-yourself Stihl 180 chainsaw carburetor adjustment

The factory Stihl chain saw carburetor plays a leading role in the model’s device. During its operation, he is responsible for mixing the fuel mixture with air and supplying it to the engine cylinder.

Before adjusting the carburetor, you will need to remove the plastic case of the tool and clean the internal parts of the saw from dust and carbon deposits. There are 3 adjusting screws under the housing cover. The first 2 screws. Marked with the letters H and L. Are needed to adjust the proportion of fuel and air, which is determined by the opening level of the throttle valve. When the screws are loosened, the fuel mixture is enriched with air, which causes the engine speed to drop. Tightening the screws reduces the amount of air used in the fuel, which leads to an increase in engine speed.

A screw marked H is required to set the maximum engine speed. Screw L is responsible for adjusting the required minimum operating speed of the motor. The third screw, marked S, is needed to fine-tune the operating idle speed of the internal combustion engine of the Stihl MS 180 chainsaw.

Setting up a German brand saw carburetor consists of two steps. The first stage is basic, or, as it is also called, factory. It can only be performed with the garden tool engine off. The second stage is final. To perform it, you need a warm, switched on motor. To know to what extent to turn the adjusting bolts, you need to read the saw manual in advance. It lists the exact setting for each individual screw. Adjusting the bolts arbitrarily without knowing their exact end position can damage the chainsaw motor.

During the basic setting of the carburetor with the cold engine off, the screws H and L must be slowly turned alternately in the direction of the clock hand to the stop. Then each of them must be turned 2 full turns in the opposite direction.

The final carburetor setting is done in this order:

  1. First you need to start the chainsaw engine and let it run for 5 minutes until it warms up completely;
  2. Next, you will need to start alternately turning the screw H in different directions until the maximum engine idle speed is found;
  3. Then the screw marked L must be turned 1/4 turn counter-clockwise;
  4. If, after the steps taken, the chain on the bus begins to rotate, then the screw S will need to be turned against the clock hand. It is only necessary to finish manipulating the screws S when the saw chain comes to a complete stop;
  5. Next, you need to set the maximum engine speed using a hand tachometer connected to the motor.

After adjusting the carburetor, you will need to check the operation of the engine. To do this, with the tool turned on, you must sharply press the gas trigger several times. If, when the trigger is pulled quickly, the engine sharply picks up speed, and when it is released, it loses it, then the factory carburetor adjustment was performed correctly.

Stihl 180 chainsaw device

The Stihl MS 180 household chainsaw is equipped with a high-quality branded internal combustion engine, from the manufacturing plant configured to work in difficult weather conditions. The single-cylinder engine of the model successfully withstands long-term high loads without increasing the amount of fuel consumed, and the forged piston group does not lend itself to corrosion and burr formation. Engine cooling. Improved by air intake. For more convenient operation, the Stihl 180 chainsaw is equipped with a factory vibration suppression system, and to reduce noise during operation. A proprietary silencer.

The tool clutch includes a proprietary drive sprocket. It can withstand prolonged loads and does not slip with a sharp increase in speed. This increases the efficiency of the Stihl chain saw when cutting dry thick logs.

To facilitate starting a cold factory engine, the Stihl MS 180 chainsaw is equipped with a decompression valve designed for manual pumping of fuel.

The working bodies of the garden tool are a reinforced metal tire on which the chain is stretched. For more precise adjustment of the saw headset tension, the Stihl model has a proprietary frontal device. Shields for the front and rear arms, as well as a chain catcher, are responsible for protecting the operator from a broken chain. To lubricate the saw headset, the model device has a proprietary Ematic lubrication system with a long-life oil pump. In addition, the manufacturer has included a spike bumper in the garden tool set for more accurate sawing of logs.

The Stihl MS 180 chainsaw stands out for its ease of use, which was achieved thanks to the manufacturer’s thoughtful arrangement of controls. The engine start button, throttle lever, factory plastic starter grip and OEM choke position switch are located at the rear of the model. A built-in inertia brake lever is installed at the front.

Air filter

On the pages of the world wide web, you can find information that the Stihl 180 chainsaw can stall due to strong pollution of the air filter. I would like to refute this not entirely correct information, and inform that the Stihl MC 180 carburetor is equipped with an expansion joint, which is designed and installed in order to take in the air necessary for the normal operation of the Stihl 180 chainsaw, bypassing the contaminated air filter. Of course, the power with a clogged air filter will drop a little, but it will definitely not stall. The power may also drop due to wear of the piston, here it will already be necessary to repair the piston Stihl MS 180 chainsaw.


One of the reasons why the chainsaw does not develop speed when you press the gas, but rather stall, is a malfunction of the carburetor. Let’s say the Stihl 180 saw worked properly, and then it was put on for a long time and did not use it. After it was started, and at idle it works well, and when you press the gas it can stall. Why stalls? The reason is a sticky carburetor injector valve. Of course, this is not 100%, but the probability of such a malfunction is high. We recommend reading an article about the device and repair of the Stihl 180 carburetor.

In order to check the injector, it is necessary to remove the carburetor and disassemble it. To remove, it is necessary to unscrew the two nuts securing the air filter and carburetor, then remove the air filter and the engine control lever, while disconnecting the choke control rod from the carburetor. Next, you need to pull the carburetor towards you a little and disconnect the fuel supply hose.

Having removed the carburetor, it must be blown out and cleaned of dirt, only after that the carburetor can be unscrewed.

It is necessary to unscrew the cover of the main chamber of the carburetor, this is the one on which the compensator is installed on top. Further, using a bolt of 8 mm and a length of at least 50 mm. We knock out the valve.

After the nozzle is removed, you can blow it out with a compressor. The valve should only let air through in one direction, if you can freely blow the valve in both directions, then it is defective and must be replaced with a new one. Collecting the chainsaw after the valve has been repaired must follow the reverse order of disassembly.

You can clearly see how the carburetor is being repaired, or rather how to properly knock out the injector valve from the carburetor body by looking

Another common reason a saw can stall when revving up is air leaking into the carburetor. It is possible to check this only with a special tool, but it is worth noting that if maintenance work on the carburetor has not been carried out for a long time, then a new set of gaskets can be installed in the carburetor. In some cases, this helps to solve the problem with its depressurization.

When disassembling the carburetor to replace the gaskets, you need to carefully inspect its needle valve, press the rocker arm and check its lifting. Sometimes, especially after the Stihl chainsaw has stood for a long time with fuel in the carburetor, the needle may burn to the carburetor body and not perform its functions. Simply put, the needle valve will not allow the fuel mixture to pass through. In this case, the saw will not work.

Why stalls at idle

The first and most common cause of this malfunction is improper carburetor adjustment. You can adjust the idle speed yourself, for this you need to have a Stihl adjusting screwdriver, which is supplied with the unit. The adjustment hole is located on the right side of the Stihl 180 saw on the handle and is marked with “-” and “” symbols.

If the Stihl chainsaw does not keep the speed and stalls at idle speed, you can be almost 90% sure that it has irregularities in the fuel pump operation system, as a rule, it is air leaks into the crankcase through the oil pan gasket, or, much more often, through the oil seals crankshaft. Air leaks reduce or completely stop the impulse, which is fed through special channels to the fuel pump of the chainsaw. As a result, the Stihl 180 chainsaw does not receive the required amount of fuel and stalls at idle.

Diagnostics can be carried out using a special device called a vacuum gauge.

The second way to check the performance of the oil seals is to pour gasoline into the crankcase of the engine and look at them, if the oil seals let gasoline pass, it means they cannot provide normal pressure in the crankcase, which will make idle work impossible. And when operating at high speeds, with leaking oil seals, there is a possibility of jamming of the crankshaft bearings.

The algorithm for checking the crankcase and Stihl 180 oil seals for leaks is as follows:

  1. The top cover is removed.
  2. The air filter housing and carburetor are dismantled.
  3. The handle of the chainsaw is removed.
  4. The starter spins and retracts.
  5. On the side opposite to the starter, the side cover and the drive sprocket are removed.
  6. A piston stopper is installed in the spark plug hole or a string from an old starter with knots imposed on it is stuffed into the cylinder.
  7. The flywheel and clutch are unscrewed, after which the parts are removed. It is worth knowing that the chainsaw clutch has a left-hand thread and unscrews clockwise.
  8. The oil pump drive gear is removed.

Having disassembled the Stihl MS 180 chainsaw, you can see the oil seals, then you need to fill the crankcase with gasoline and check the leakage. You can fill the crankcase through the fuel window in the cylinder, for this the piston must be raised as high as possible. If leaks are found, it is necessary to replace the defective oil seals, or re-seal the pallet. You can collect Stihl 180 following the reverse sequence of the algorithm.

What to do if a chainsaw stalls?

Builders, installers, rescuers and summer residents. All of them, sooner or later, completing their tasks, take up the chainsaw. And the final result of their activity largely depends on how reliably this tool will work.

The chainsaw is used to cut wood.

It is worth noting that the chainsaw belongs to relatively simple devices. Nevertheless, it, like other mechanisms, periodically fails. When a chainsaw stalls while idling (this is one of the most common malfunctions), the biggest problem is to determine the reasons for this behavior of the device. If the source of the “disease” is correctly installed, it will not be so difficult to return the apparatus to a working position.

Therefore, the first step is to find out what kind of malfunctions there are with a chainsaw and what leads to engine stops at idle.

Spark Plug Problems and Solutions

It is generally recommended to change this key component of the ignition system at least once a year. But often saw owners forget about this rule. And therefore it should not be surprising that the device, the maintenance of which is carried out fragmentarily, as a result, poorly “keeps” idling.

The spark plug of the chainsaw must be changed once a year.

Therefore, you should pay attention to the following malfunctions associated with the operation of this system:

  1. Filling the spark plug with gasoline at the time of start. To eliminate the problem, turn out the candle and, without igniting, dry it. Excess gasoline is drained from the engine through the hole-socket into which the candle is screwed. After a break of 30 minutes, the candle is put in place, the mechanism starts.
  2. No spark due to poor contact of the spark plug tip with the high voltage wire. The connection is checked, in case of violation, the defect is eliminated.
  3. There is no spark due to a malfunction of the electronic ignition unit. If there is confidence in the reliability of the connection of the tip with the high-voltage wire, but there is still no spark when the starter is on, then the cause of the breakdown may be a malfunction of the ignition unit. This component is not restored, it is only replaced with a new one.
  4. Incorrect spark plug gap. In different types of candles, this indicator ranges from 0.2 to 0.5 mm. The correct clearance is established with a feeler gauge of the appropriate thickness. A larger or smaller gap for a given type of plugs is not allowed.

Meanwhile, during the initial inspection of the spark plug, it may turn out that the reason why the chainsaw refuses to work is not at all in the defects of the spark plug or other elements of the ignition system.

Spark plugs can indicate a saw malfunction.

So, if the candle turns out to be completely dry, this may mean that the original problem lies in the impossibility of fuel entering the combustion chamber. In this case, the entire gasoline supply chain should be checked from the carburetor itself.

At the same time, the presence of a characteristic black carbon deposit on the candle body is a sign that, probably, the carburetor is poorly adjusted. This causes the fuel mixture to become oversaturated with gasoline. Oil may have spilled into the fuel. In this case, clean the spark plug, replace the fuel and adjust the carburetor.

Problems associated with improper operation of the fuel system

The chainsaw periodically stalls at idle speed also due to a violation of the integrity of the fuel line or an incorrect ratio of the ingredients of the “fuel mixture” consisting of gasoline and oil.

Before each switching on of the cutting mechanism, it is necessary to visually inspect its blocks and assemblies, paying attention to possible defects in the surface of the body, mechanical damage, and leaks of working fluids. This also applies to the saw fuel line, which is usually a rubber tube.

If the device was (especially for a long time) in a damp place and it had to withstand sharp fluctuations in air temperatures, this tube could simply crack. This fuel line is not suitable for further use and should be replaced.

Another reason why a chainsaw can stall at idle speed is non-compliance with the ratio of ingredients when preparing the “fuel mixture”. The proportions of gasoline and oil included in it must exactly correspond to the proprietary instructions for a particular device. If they are not observed, the engine will not be lubricated sufficiently and the entire mechanism will stall persistently.