Chainsaw starts and stops. Why?
There are a few simple rules for the operation and maintenance of the chainsaw, which, if followed, will maximize its service life. Cooking the right fuel mixture, regular cleaning of the filters and periodic replacement of parts will save you from having to repair your tool for a long time If the failure is not avoided, you can solve it on your own. This applies to any brand of chainsaw, from the more complex models “Husqvarna” and “STIHL” to the simplest models “Makita” and “Patriot”.
The chain saw shuts down straight away
What to do if your chain saw stops shortly after you start it?? First you need to check that there is fuel in the gas tank. If its level is not enough, you need to prepare a fuel mixture in exact accordance with the ratio of gasoline and oil prescribed in the instruction manual. Gasoline must have the highest possible octane rating and the proper oil grade is usually listed on the chainsaw data sheet.
Next, we check the spark plug, as well as the contact of its tip with the high-voltage wire. The gap between them must not exceed 0,5 mm. If necessary, the spark plug is cleaned of soot and dried. It is recommended to change the spark plug from time to time with a completely new one. The causes of the tool stopping on the gas are in the fuel filter or carburettor jets. Cleaning the gasoline filter will not take much time and effort, but disassembly and cleaning the carburetor is better to trust the specialists of the service center.
Chainsaw stalls when idling
It is not uncommon for a chainsaw to stall at idle speed. First of all, you need to check the muffler, and if it is dirty, clean it from the exhaust tar deposits. Also on the carburetors of some models, etc. there are screws labelled H and L, which mean rough and fine adjustment respectively. By adjusting the bolt L while the chain saw is running in such a way that its speed increases (it is enough to turn the bolt only by half a turn), it is possible to eliminate the given problem. Adjusting the carburetor requires the obligatory presence of an electronic tachometer and is quite a time-consuming process. That is why in such cases, it is better to turn to professionals.
Chainsaw stalls under load
If the chainsaw stalls on load, then the reason for this may be the fuel system or a dirty air filter. Changing the fuel in the right gasoline/oil ratio or cleaning the air filter are universal solutions to such problems. An improper mixture of low-quality gasoline and, for example, machine oil, is the main cause of a chainsaw malfunctioning, including when it heats up and stops.
Chainsaw stops when tilted
When the chainsaw is horizontal, the fuel tube is at the bottom of the gas tank, but when the tool is tilted, the tube is over the fuel mixture, i.e.е. in the air. This is what causes the chainsaw to stall on its side.
The chain saw cuts out at high engine speeds
If you think the machine is stalling at high engine speeds, there are three things to check: the air filter, the fuel pump and the gasoline filter. The air filter has to be cleaned, you can even wash it under water and let it air dry. Then it is enough to disconnect the fuel hose from the carburetor and see if the fuel leaks from it or not. If it is flowing in a full stream, you don’t need to check the gasoline filter. If it is the other way around, the fault is found. The breather plug can be cleaned with an ordinary needle, and the filter can be carefully disconnected from the suction hose, cleaned or replaced with a new one. Check the gasoline pump for wear: if there is no fuel leaking through it, there is nothing wrong with it. If the problem with your tool stopping at full throttle is due to some damage to the pump, simply replace the part with a new one.
Gardening Equipment Repair and Service.
Your Chainsaw Stalls? You Can Fix It, Here’s How
Specialized Service Center “Agrotehservice. Warranty and after warranty service of world manufacturers equipment! Attention! Notes for Users!
Your chain saw starts and stops. Why?
The 1st and most frequent reason of this malfunction. Wrong carburetor adjustment. You can adjust the no-load speed unassisted, and that’s why you need the STIHL adjustable screwdriver that comes with the machine. The adjustment hole is located on the right side of the STIHL 100 eighty on the handle and is marked with “-” and ” “.
If the STIHL chain saw does not maintain speed and does not work at idle, you can be almost 90% sure that it has a problem with the fuel pump system, usually a leak of air into the crankcase through the gasket oil compartment, or, even more often through the crankshaft seals. Air leaks reduce or one hundred percent stop the impulse that is delivered through special channels to the chainsaw’s fuel pump. As a result, STIHL 10080 chain saw doesn’t get the right amount of fuel and doesn’t run at idle.
Diagnosis can be made with a special device called a vacuum gauge.
Second method to check the oil seals for proper functioning. Pour gasoline into the crankcase and look at them, if the oil seals are leaking gasoline, they can not provide the normal pressure in the crankcase, which will make standby operation not feasible. And when working at the highest speed, with leaking oil seals, there is a possibility of seizing the crankshaft bearings.
The method for checking the crankcase and oil seals of the STIHL 100 eighty for leaks is as follows:
- Removable top cover.
- Remove air filter housing and carburetor.
- The chainsaw handle is removed.
- The starter spins and retracts.
- Side cover and drive sprocket can be removed from the starter.
- A piston plug is installed in the hole for the spark plug, or a string from an old starter is stuffed into the cylinder with the nodes superimposed on it.
- The flywheel and clutch are unscrewed, then the parts are removed. It is worth knowing that the chainsaw clutch has a left-hand thread and is unscrewed in a clockwise direction.
- Oil pump drive wheel is removed.
Disassemble the STIHL MS 180 chain saw, you can see the oil seals, then you need to fill the crankcase with petrol and check for leaks. The crankcase can be filled via the fuel window in the cylinder; to do so, raise the piston as high as possible. If leaks are detected, faulty oil seals must be replaced or the oil pan re-sealed. You can assemble the STIHL 180 in the reverse order of the method.
Internal combustion engine characteristics of chainsaws
The main chainsaw malfunctions are related to engine failures. Domestic and foreign manufacturers use single-cylinder two-stroke internal combustion engines as the chain drive. The design of the motor is simple. Ignition is normal, without the installation of cranky electronics. Chainsaw engines can operate reliably in various climates. Fuel for the carburetor engine is obtained by mixing AI-92 gasoline and special oil. Since there is no oil pump, the piston and cylinder are lubricated by a mixture of gasoline and oil. The chainsaw engine has a power output of 2 to 5 kW and a crankshaft speed of up to 14,000 rpm. Such high RPM and loads place very high demands on the oil. Use the oil specified in the instruction manual. When oil is changed to normal engine oil the tool life is drastically reduced. Remember, it is strictly forbidden to fill the tank with gasoline without adding oil.
Why gasoline does not flow into the chain saw?
Carburetor needle. On cheap chainsaws, the carburetor needle is often resting in the carburetor, preventing fuel from entering. Sometimes you just need to move the needle and install it correctly.
Gaskets. Chinese and even brand name chain saws can have poor quality seals with poor sealing. Fuel stops flowing when it begins to compress the fuel mixture through the seals. Gasoline leakage is possible because of gaskets.
How To a Fix a Chainsaw that keeps flooding and dying at idle and bogs on throttle acceleration
READ STIHL STIHL STIHL STIHL STIHL STIHL STIHL STIHL STIHL STIHL 100 eighty circular saws
Check your breathing
It is the fan that plays a significant role in the installation of a chainsaw, such a part can be found near the fuel tank lid, more precisely. In the area of the air hole. The breather has a simple but important role. It prevents fuel leakage and sets the correct air pressure. This is why air gets into the carburetor, and failure of this element is a frequent reason for not getting fuel to the chainsaw. Failure of the blower will result in negative pressure, preventing gasoline from entering the carburetor when attempting to start the tool.
To check the fan is simple enough, disconnect the gas tube from the carburetor and check the fuel consumption. If gasoline leaks in a small stream, it’s okay if it doesn’t leak at all. Breathing apparatus is quite clogged with dirt. If done correctly, the part can be cleaned, sometimes it is easier to replace it with a new one. The cleaning procedure is done manually or with a strong jet of compressed air.
There can be many breakdowns with a chainsaw, and some of them are difficult to solve. If you have worked with this gas tool for a long time, you have a problem when the gasoline does not get into the carburetor, but it is very difficult and does not allow you to properly start the chainsaw. Fortunately, experts have long ago found the causes of such a breakdown, so we have compiled the main methods of repair.
First of all, we check for trivial reasons, such as the presence of gasoline in the tank. If so, we check the process of pumping fuel from the tank through the wire. To do this, simply disconnect the gas line from the carburetor and try to pump fuel. Properly pumping fuel through the hose jerkily will ensure that there are no problems with the gas tank. If the fuel does not flow even jerkily or drains too slowly, the causes may be:
Surprisingly, even having a full tank can be the reason when fuel is not coming in. Therefore, try not to fill the tank as much as possible. An overfilled fuel tank can squeeze the pipe that connects to the carburetor.
Low quality gasoline
Every experienced chainsaw user knows that fuel should not be left in the tool’s tank for long periods of time. The fact that prolonged storage inside the tank will cause unnecessary processes with the formation of resin and polymerization of various components. Do not leave fuel in the tank for more than 2 weeks and even if your tool is started with this fuel, it can lead to soot deposits on the parts of the CPG (rings, piston).
If the chainsaw is not getting gas into the carburetor, pay attention to the type of air filter. Improper operation causes the chainsaw to become unstable and difficult to start later or stop during operation. Air is harder to get into the unit and the mixture becomes too saturated. You are unlikely to be able to start it, and dust buildup is the cause.
Care must be taken when removing the air filter, because if dust is left on it, it can get into the carburetor. Clean the air filter well enough with water and detergent. Be sure to dry the filter before installing.
Why the chainsaw won’t start. causes and solutions
Each model has its own weak points. Some saws require regular carburetor adjustments. The chain lubrication system is the weak point of others. No matter what, you can fix it yourself if you know what the cause is and what the symptoms are.
What to do if the chainsaw stalls on the throttle?
As a rule, chainsaw owners start to encounter this breakdown after the first 6 months of intensive use of the tool. There could be several possible causes.
- Using a fuel mixture prepared in the wrong proportion. If you regularly fill the gasoline tank of a chainsaw with too much or too little oil, the tool will not start. In this case it is necessary to drain the fuel as well as dry the engine cylinder. To do this, pull the starter rope sharply several times. After that, you need to pour in properly prepared fuel, and start the saw engine;
- Filling the spark plug with oil when starting the engine. This problem can be solved by removing, cleaning and drying the spark plug. After 30 minutes the spark plug is dry and can be screwed in. After that, it will be necessary to start the chainsaw;
- no spark. This indicates poor contact between the factory high voltage wire and the tip of the spark plug. If the contact is not broken, but there is still no spark, then it is necessary to check the electronic block of the ignition system of the chainsaw. This element can not be repaired, so it will need to be completely replaced;
- clogging of the air filter. This part of the saw should be regularly cleaned of debris, small insects and dust. Otherwise, air won’t get into the carburetor, where it should enrich the fuel mixture. This will cause the saw to stop starting. To solve the problem, you will need to clean the filter, or replace it.
In most cases, the chainsaw stops starting due to the use of low-quality fuel and engine oil. There is no need to save on working fluids, as this will lead to a difficult and lengthy repair.
How to start a chainsaw correctly. common methods
Every time properly starting the engine of the household gasoline chainsaw, its owner ensures a well-coordinated and smooth operation of the mechanisms of the garden tool, as well as prevents rapid wear and tear of its consumable parts. The procedure for starting the cold engine of different models may vary slightly, but in most cases, it looks as follows:
- The first step the operator is sure to take is to set the lever that adjusts the position of the throttle’s built-in choke to its lowest position. Note that you can only move the lever to this mode if the throttle trigger is held. By moving the lever down, the operator will close the choke located in the regular carburetor and lock the throttle lever in the clamped position;
- Next, you need to start manipulating the starter rope. To do this, you need to put your right foot in the lug located in the back of the body, and rest your left hand on the handle of the chainsaw. Then pull the integrated starter rope of the garden tool sharply several times. As soon as the engine starts and stops, the throttle position lever should be moved up one position;
- After that it is necessary again several times sharply pull the pull cord of the hand starter. As a result the engine of the saw should start and immediately start working at extremely high rpm. This is due to the operator having previously locked the throttle trigger in the clamped position;
- Then you have to squeeze the throttle trigger once and immediately release it. The throttle lever should then move back into its operating position. At the same time the engine rpm will drop. This means that you can start to operate the chain saw on the site.
If the operator needs to start the garden tool with a warm motor, the throttle valve position lever must be moved to the penultimate position upwards and the starter rope pulled for this purpose. To switch off the engine, the choke shut-off lever has to be moved to the extreme up position.
Top Reasons Chainsaw Starts, Then Stalls — Chainsaw Troubleshooting
The factory engine can be started in the following sequence on some of the chainsaws used in the household:
- First, the ignition must be turned on and the toggle switch must be placed in the appropriate operating position;
- Next, you need to press the transparent plastic primer 5-6 times, required to pump fuel into the cylinder;
- The operator will then have to pull out the inboard choke adjustment lever fully;
- Then pull the recoil starter rope sharply several times. As soon as the factory engine starts and stalls, the throttle control lever must be pushed all the way in and the starter lever must be pulled several more times. The operating instructions for some models specify that once the engine has stalled, the throttle control lever only needs to be pulled halfway. You should pull the lever all the way down only after the chain saw’s engine starts to work steadily;
- In models where the throttle trigger is fixed by pulling the throttle control lever, the engine will start at high rpm. If the throttle trigger is not locked in the chainsaw, the engine speed will be minimal. This could cause the engine to stall a few seconds after starting. In this case, start the motor of the garden tool until it warms up and starts working more steadily.
If the operator has to start the chainsaw with a warm motor, all he has to do is switch on the ignition and pull the starter rope a few times sharply.
Chainsaw stalls at high RPM. simple carburetor repair
The tool’s carburetor is exactly the mechanism that most owners are wary of dismantling on their own. The reason is that this mechanism consists of many small parts, the location of which you need to remember when carrying out disassembly work. However, not everything is as terrible and difficult as it may seem. To understand what relation the carburetor has to the problem of the engine stopping working when the revs are increased, you need to know its principle of operation, described on the site.
The chainsaw stalls when you press the gas because of the carburetor, if:
- The diaphragm is damaged
- The filter element is clogged (the mesh in the carburetor). This malfunction can be encountered by owners of tools that have no fuel filter or it is simply disconnected from the fuel hose
It is recommended to clean and wash the carburetor of a chainsaw, as well as replace defective parts and elements. After that it can be put back, not forgetting also to replace (if worn) the gasket between the carburetor and the adapter.
Adjusting the carburetor when the engine stalls at revs
If the check showed that the fuel system, muffler and spark plug are serviceable, then you need to look for a breakdown in other places. The first step is not to disassemble the cylinder and piston assembly or replace the carburetor. We recommend that you start with adjusting the carburetor. All chainsaws have special adjustment screws for this purpose. They are intended for adjusting the idle speed as well as adjusting the fuel supply at low and high revs. A detailed description of how to adjust the carburetor of a chainsaw, described on the site.
Today, let’s consider the peculiarities of carburetor settings at maximum speeds. Make sure that the chainsaw does not develop full power, you can use the tachometer. If there is no device, it is possible to make sure that the engine does not develop maximal revolutions, by hearing. We are interested in the screw on the carburetor. which is intended for tuning high revolutions. It is usually designated by the Latin letter “H”, which is abbreviated from the word “High” (high or large).
To adjust the chainsaw high rpm you will need to do the following manipulations:
- Turn the “H” screw clockwise as far as it will go
- Then loosen it by 1.25-1.5 turns
- Start the tool and check that the RPM is working
It is advisable to read the tachometer, but if it is not available, you can check the maximum rpm with the tool under load.
After a trivial adjustment of the carburetor, you can fix the problem with the engine stopping at higher revs. It should be noted that it is necessary to adjust the carburetor chainsaw regularly, depending on the frequency of use of the tool. It is not difficult to do it yourself, but it is possible to achieve an accurate setting in one case. if you use a tachometer.
Frequent problems with the Husqvarna 236-240 chain saw
If the engine can’t be started, take the following steps in sequence:
Locate the air filter and spark plug.
- Check that there is gasoline in the tank.
- Change the fuel if it has been stored for more than a month.
- Check the fuel filter. Disconnect the hose from the carburetor and watch the trickle. If gasoline is flowing freely, the fuel filter is not clogged. If not enough flow, clean the hole in the tank cap or the filter.
- Clean air filter. The air filter can be removed for a test run.
- Inspect and clean the muffler for cinders.
- Check that the starter is working properly. If necessary, repair the starter (replace the pulley, spring or cable).
- Take apart and clean the clogged carburetor.
- Use a tester to check high-voltage wire for a breakage.
- Measure the gap between the flywheel magnets and the ignition module (should be 0.2 mm).
- Unscrew plug and inspect it. Measure the gap between the electrodes with a feeler gauge (normally 0.5-0.6 mm). By the appearance of electrodes determine the nature of the fault. If the spark plug is dry, there is no flow of the working mixture. The working part, flooded with gasoline, indicates a low-quality adjustment of the carburetor or the absence of spark. To check for spark, connect the high-voltage tip to the spark plug, place the skirt on the cylinder radiator, and pull the starter cord. If there is no discharge between the electrodes you need to replace the spark plug. Carbon deposits on the electrodes indicate a low quality fuel mixture. The center and side electrodes should be sanded with sandpaper.
- No compression. The reason. failure of piston group. Measure compression. First you have to unscrew the spark plug. Then insert a pressure gauge into the cylinder bore and use the starter cord to move the piston. The condition of the cylinder piston group is judged by the pressure in the cylinder. It must be at least 8 atm. Low values are caused by wear of the cylinder, piston, piston rings.