A chainsaw is a relatively simple device, which is used from time to time by summer residents, installers, builders and rescuers. Construction stores offer a lot of models of chainsaws, which vary in power and quality of work. However, this practical and unique technique can also fail.
If such a problem occurs, it is very important to find the cause of the malfunction and eliminate it as quickly as possible. To do this, it is not necessary to contact services where the equipment will be put in order for a fee. Sometimes the breakdown can be so minor that it is not difficult to deal with it yourself.
How does the tool factory work?
Chainsaw equipped carburetor two-stroke engine, which is practically its main element. Its power depends on the model of the equipment and its intended purpose.
The chainsaw saw set includes:
- cutting chain;
- sprocket;
- stars;
- tires.
The larger the pitch the headset has, the more powerful and productive it will be, and therefore the cut will be deeper. Therefore, the engine should not be inferior to it in terms of power, otherwise the operation of the tool will be inferior.
The chainsaw is lubricated with special oil directly from the second tank located on the hand block. Its mass has such features that the fuel and oil intended for the engine run out at the same time.
We have become familiar with the basic elements of the tool; now it will be easier to understand the reasons why a chainsaw may stop working and how to eliminate them.
Causes of malfunctions and ways to eliminate them
Almost every chainsaw owner has at least once encountered the fact that the tool either does not start at all when you press the gas, or starts and stalls after a while. There can be many reasons for a device to malfunction. Some of them are quite simple and easily eliminated. Therefore, it is worth studying the main reasons so that in the event of a basic breakdown, you do not take the tool to a chainsaw repair service.
Why does a chainsaw start and immediately stall?
There may be several reasons for this:
- There is not enough fuel in the gas tank. If the tool stops working immediately after the factory, then first of all you need to check the presence of fuel in the gas tank. If it is not enough, then you need to add the fuel mixture, which is prepared strictly according to the instructions included with the tool. Chainsaw fuel consists of gasoline with the highest possible octane number and oil, the brand of which must be specified in the technical passport of the tool.
- Poor contact between spark plugs and high-voltage wire. The gap between the spark plug tip and the wire should be no more than 0.5 mm. If carbon deposits have formed on the candle, it must be cleaned and dried. Experts recommend periodically updating spark plugs, even if the old ones are still working properly.
- Pouring a candle. A large amount of fuel collects between the spark plug electrodes, so if the spark plug is flooded, a spark will not form. To fix such a breakdown, just remove the spark plug and dry it. It would be useful to heat it using a gas burner.
- Carburetor jet or fuel filter is dirty. It is quite easy to clean the gas filter yourself, but it is better to entrust cleaning the carburetor to specialists.
The chainsaw malfunctions at idle speed
The cause of this malfunction may be dirty muffler. Therefore, in order for the tool to work properly, sometimes you just need to clean the muffler of exhaust tar deposits.
Quite often, the air filter in the tool becomes clogged, the air flow into the system becomes clogged, and this leads to the device stalling at idle.
To clean the air filter, it must be carefully pulled out, making sure that dust from it does not fall on the carburetor. Next, the filter is thoroughly washed with detergents, dried and replaced.
The chainsaw may stop idling due to fuel filter problems. To check it, you need to disconnect the fuel line from the carburetor. If, when pumping, fuel hardly flows out of the hose and flows poorly to the carburetor, then most likely the filter is clogged with debris.
To clean it, you must first drain all the fuel and then remove the filter from the tank. This is done using a wire hook through the filler head of the tank. The filter is then disconnected from the hose and cleaned.
For normal operation of the chainsaw, it is recommended to change the air and fuel filters every three months.
A chainsaw may stall at idle when it has fuel line is damaged. Therefore, each time before starting work, it is recommended to inspect the mechanism, its components and blocks for possible mechanical damage to the housing and fuel drive, and liquid leaks.
If the instrument was stored in a damp place for a long time or was exposed to temperature changes, the tube could simply crack. In this case, it must be replaced with a new one.
If the chainsaw does not want to idle, then the reason for this may be non-compliance with the ratio of gasoline and oil when preparing the fuel mixture. The proportions must strictly comply with the instructions supplied with the chainsaw. If they are not followed, the engine will not be sufficiently lubricated, as a result of which the mechanism will begin to stall.
The chainsaw does not work at high speeds
At high speeds, the tool may begin to stall due to malfunctions:
- gasoline pump;
- fuel filter;
- air filter.
To trust a gasoline pump, you need to see whether fuel is leaking through it or not. If it is damaged, then most likely the chainsaw will stall at full speed because of this, and the pump needs to be replaced with a new one.
To check fuel filter, just disconnect the hose from the carburetor and see whether gasoline flows out of it or not. If it flows in full stream, then everything is fine. Otherwise, the fuel filter must be cleaned or replaced with a new one.
To clean the air filter, you simply need to wash it under running water and then dry it thoroughly.
The tool motor cannot withstand the loads
If the chainsaw often stalls when cutting thick logs, then problems should be looked for in the air filters or fuel supply system.
When working under heavy load, the engine may simply not receive enough fuel and stop. Therefore, this problem can be eliminated by cleaning the air filter or replacing the fuel, which must be prepared strictly according to the recommendations of the instructions.
The new chainsaw does not want to work
In principle, there shouldn’t be any problems with the new tool, but if it still doesn’t start, then most likely it’s manufacturing defects or all instructions in the instructions are not followed.
To fix this problem, you should first look to see if everything is screwed and connected, as required by the instructions.
The cause of the malfunction may also be an incorrectly prepared fuel mixture. The performance of a chainsaw can be affected by poor quality ingredients used to make the fuel. It is best to choose tool oil from a well-known manufacturer, so that problems do not arise later during operation.
If everything was done strictly according to the instructions, but the chainsaw still does not work, then you will have to contact a service workshop.
Failures of the cylinder-piston group
If all the above-described malfunctions are eliminated, and the chainsaw still stalls when you press the gas, then the cause will need to be looked for in the engine, or more precisely, in its cylinder.
Sometimes the performance of a cylinder-piston group can be determined simply visually. It will not be possible to start the saw if there are scuffs, chips and other defects. In this case, the parts must be replaced.
When you press the gas, the tool may not start or even stop working if the piston rings are damaged. Therefore, if there are no other obvious reasons, it is necessary to investigate the rings, damage to which leads to loss of engine power. The fact that it is time to change the rings is indicated by their free play in the cylinder grooves.
However, in order to fully understand the technical condition of the cylinder-piston group, the engine should be completely disassembled. This work is labor-intensive and only a specialist can do it.
Undoubtedly, equipment failure can upset its owner. But you shouldn’t despair ahead of time, because some breakdowns can be fixed on your own. If the chainsaw does not start when you press the gas, this does not mean that you immediately need to take it to the workshop. In some cases, it will be enough to simply follow the advice of specialists described in this article.
There are situations when even the newest chainsaw stalls at idle. This situation is associated with the factory carburetor settings or lack thereof. It happens that during long-term transportation, the carb of the tool also becomes out of adjustment, because improper maintenance conditions are enough for this to happen. The chainsaw stalls at idle and due to a malfunction of the fuel pump. Why this happens - you need to understand the crankshaft seals and pan gaskets, as well as other components of the fuel supply system. In this article we are interested in each possible cause and the stages of its resolution. , how to repair it correctly and quickly, the specialists of the KosiKosa store will always help you.
It is important for owners of gas powered tools to understand that the saw can stall not only at idle and not pick up speed, but also at maximum and minimum speed. All these situations are interconnected, and the reasons for their elimination are also of a similar nature.
Does your chainsaw stall at idle? There is an exit
If the saw starts to stall at idle, then there are a priori several reasons, and it will be easy to find out even for a novice owner if you follow the recommendations of our specialists and check everything competently and delicately. So, the reasons why chainsaw stalls at idle may be the following:
- reduction in the capacity of gasoline and air filters;
- malfunctions in the ignition system, also referred to as its abnormal operation;
- spontaneous change in carb settings;
- elements of the fuel supply system are faulty;
- the muffler or exhaust ducts are clogged;
- the occurrence of defects on the piston, cylinder or other elements of the CPG, defects on the valve;
Before checking the insides of the saw to find out why the tool stalls at idle, you need to inspect all its external components for any deviations, which may include possible deformations, and also check for the presence of fuel in the tank. Let's consider each of these situations:
- We check and repair filters. If the fuel or air filter is clogged, the engine receives insufficient amounts of air or fuel, or does not receive one of the elements at all, and accordingly cannot operate fully. We remove the fuel line hose from the carb fitting and direct it into a working container. Click on “paging” several times and look at the result. With a clean fuel filter, gasoline flows evenly, clearly, without jerks and vice versa. To check the air filter, you need to remove it carefully so that sawdust and dirt do not get into the carb. After washing it, blowing it or replacing it with a new one, we analyze the result to see whether the problem was in two or one of the filters.
- We check the ignition system and the spark plug itself. Its poor condition can cause the saw to fail to operate at idle speed, if it stalls when you give it gas or even fails to start at all. So, the candle could have been filled with fuel; a spark does not occur due to a huge amount of carbon deposits or a burnt-out spark plug element; a spark does not occur if the gap between the electrodes is violated (too large or small); a dry spark plug will indicate a lack of gasoline in the piston cylinder; Incorrect carburetor adjustment and a clogged air filter can be determined by the presence of black carbon deposits on the spark plug and soot on its electrodes.
- Why, after checking the ignition system and filters, the saw continues to stall at idle - the cause can only be the carburetor. You need to find three adjustment screws, among which one is responsible for maximum speed, the second for minimum speed and idle speed (the screw is called “T”). It must be configured according to the recommendations, strictly according to the instructions for each individual device. If even adjusting the idle speed did not help, and the saw continues to stall at the same speed, proceed to disassembling and inspecting the whole crab. We describe how to do this in our articles.
- Malfunctions, breakdowns, clogging of the chainsaw muffler. The last option, which provokes situations at idle when the saw stalls. A muffler contaminated with sawdust and dirt, with adhering oils and exhaust gases, loses its throughput. If it is not cleaned and replaced in time, the engine will begin to “choke.” All elements associated with the muffler must be gently soaked, carefully cleaned and blown with compressed air, and installed in their place. At this moment, cover the engine with a rag to prevent dust from entering.
If your Husqvarna saw or Shtil power tool stalls at idle speed, we have presented you with all the existing testing options. It is also important to correctly assemble all the parts during disassembly in their original place, drain the gasoline, if any, replace it with a clean mixture and try to start the saw. You can always order on the KosiKosa service.
If you already understand the reason why your saw stalls at idle, but don’t yet know how to approach disassembling or removing a separate part, say, a carburetor - watch the video from other articles from our specialists, read the step-by-step instructions in the articles. We also recommend that you treat all moving elements with extreme caution to avoid injury. Other important recommendations include:
Prices for chainsaws are falling and this makes them more popular and affordable not only for professionals, but also for ordinary, so to speak, amateurs. However, a common dependence - the lower the price, the less reliable the device and the more often malfunctions appear, is also relevant for chainsaws. But for a chainsaw of any price range, most malfunctions can be avoided with proper operation, care and timely maintenance of the equipment. But no one is immune from the breakdown of a chainsaw, as well as any other equipment. It is therefore proposed to consider main types of chainsaw malfunctions, methods for diagnosing, eliminating and repairing them.
All the main malfunctions of chainsaws can be divided into two main categories:
- malfunctions of the engine and its various components: fuel preparation and supply system, ignition, piston group with crankshaft, exhaust gas exhaust system;
- malfunctions and breakdowns of other components: lubrication system, clutch, chain brake, tire and others.
Chainsaw engine malfunctions
Here are various malfunctions in the operation of a chainsaw engine that occur most often. These main malfunctions boil down to the following symptoms:
the engine does not start (quite general and the reasons can be quite different);
works unsteadily;
starts, but often stalls;
overheats quickly;
does not develop power, i.e. It runs fine at idle, but stalls or "chokes" under load.
It smokes a lot and the power drops.
Problems starting the engine
It is very important to correctly determine the cause of the malfunction, because otherwise we simply cannot eliminate it. If, when trying to start the chainsaw, there are no extraneous sounds (knocking, grinding, etc.), then very often it turns out that in fact there is no breakdown. For example, if you start the chainsaw incorrectly and pull the choke for a long time, the engine simply floods and it is very difficult to start it.
In order to properly start a cold chainsaw engine, set the lever or switch to the “throttle closed” position. Then you need to pump the mixture into the carburetor, if there is a fuel priming pump. Pull out the starting handle until the engine resistance becomes noticeable, and vigorously pull in amplitude, moving your hand to the side. After two or three such movements, the engine should first start and then stall. If this does not happen, then you need to move the lever to the half-throttle position or simply to the working position and then continue to start the chainsaw in this mode. For many chainsaws, the “half throttle” is automatically locked when the air damper is pulled out. Some models have a key ignition switch; it is important to make sure it is turned on.
If the engine does not start, then the first thing to do is unscrew and inspect the spark plug. There are cases when at a plant in the cold season, the combustion chamber is filled with fuel. Then you also need to unscrew the spark plug, dry the combustion chamber by idling, clean the spark plug, screw it in and repeat the start. It is advisable to immediately check for the presence of a spark - put a cap with a high-voltage wire on the unscrewed spark plug, place it on the cylinder and pull the starter. Visually we observe a frequent blue spark - good. Screw the spark plug into place and start it. If there is no spark, change the spark plug and try again. No again - we check the connection of the high-voltage wire to the spark plug, the coil and the ignition system.
In general, the type of malfunction can be judged by the condition of the spark plug.
- Dry. Most likely, the fuel mixture is not getting into the cylinder. The problem is not in the ignition system, so screw the spark plug back in and check the fuel supply system.
- Wet, heavily splashed with fuel. The reason for the excess fuel mixture lies either in a violation of the starting rules, as described above, or in incorrect carburetor adjustment.
- Covered with black soot. This may indicate the use of low-quality oil, an incorrectly adjusted carburetor, or an incorrectly calculated ratio of gasoline to oil. The spark plug should be washed, removed from carbon deposits with a sharp object (an awl or a needle), the electrodes should be wiped with sandpaper and placed in place.
When checking the spark plug, you need to pay attention to the gap between the electrodes: 0.5 to 0.65 mm is considered normal. A damaged or worn gasket must be replaced.
Checking and adjusting the chainsaw carburetor
A properly adjusted chainsaw carburetor ensures that it operates efficiently at full power with the most economical fuel consumption.
The need to adjust the carburetor of a chainsaw rarely arises, since the adjustment is initially carried out by the manufacturer to achieve optimal operating mode. The adjusting screws are designed for more precise adjustment of the chainsaw carburetor if necessary.
When and why does this need arise?
Among the reasons for the failure of fixation of the adjusting screws, the most common are the following:
- Severe vibration or damage to the protective cap. This happens rarely, but it does happen.
- Serious engine wear (piston). Of course, in this case it is worth taking more care of repairing the chainsaw engine, but still adjusting the carburetor can improve its functionality for a while.
- Blockage in the carburetor due to damage to the air filter, poor quality gasoline or due to the formation of scale. In this case, in addition to adjusting the carburetor, flushing it cannot be avoided.
What signs indicate the need to adjust a chainsaw carburetor?
- Firstly, the engine does not start, or it starts, but immediately stalls. This most often occurs due to a lean fuel mixture.
- Secondly, a significant increase in fuel consumption and exhaust emissions. An increase in exhaust emissions indicates that the fuel does not burn completely, which means that the cause may be oversaturation of the fuel mixture.
The scheme for adjusting the carburetor of a chainsaw may differ slightly depending on the manufacturer (the process of adjusting the carburetor of a chainsaw of a specific brand and model is described in detail in the operating instructions), but the general principles remain the same for all brands. The purpose of adjusting the saw is to change the quantity and quality (richness) of the fuel mixture supplied to the engine cylinder.
To learn how to adjust the carburetor on a chainsaw, you should learn to distinguish between three screws (some models have only one).
Screws L and H are similar only in appearance, in fact they are different
Each screw has its own letter designation:
- “L” is used to adjust low speed;
- “H” is necessary to adjust the upper speed;
- “T” is needed to adjust the idle speed (models with one screw only have it).
There are mandatory safety requirements that must be observed when adjusting the carburetor of any chainsaw:
- Make sure the chain is facing away from you.
- The saw must be firmly positioned on a level surface, and its cutting part must not touch any objects.
Please note: you will find the exact values of the angle of rotation of the adjusting screws in the operating instructions for your specific chainsaw model. Carefully following the manufacturer's instructions will help you avoid engine damage.
The process of setting up a chainsaw carburetor consists of two stages: basic (engine off) and final (warm engine running).
Basic adjustment of a chainsaw carburetor
Slowly turn the maximum and minimum speed adjustment screws (H and L) clockwise until they stop, then turn them counterclockwise 1.5 turns.
Final adjustment of the chainsaw carburetor
Idle speed adjustment
Before this adjustment step, it is necessary to warm up the engine for 5-10 minutes, avoiding high speeds.
By turning the idle speed adjustment screw (T/LA/S) counterclockwise, achieve the minimum speed at which stable engine operation will be ensured. Make sure the chain does not move. That is, if the engine stops at idle, turn the idle speed adjustment screw clockwise. If the chain is driven, turn the screw counterclockwise.
To complete the adjustment of the chainsaw carburetor, you need to check the engine for acceleration and maximum speed.
Acceleration check
To check the engine for acceleration, gently press the accelerator and make sure that the engine quickly picks up speed from idle to maximum speed (from 2800 to 11500-15000 revolutions - depending on the brand and model of the saw). If the engine picks up speed slowly, slowly turn screw L counterclockwise (no more than 1/8 turn).
Adjusting the maximum speed
The maximum speed is adjusted using screw H. The speed increases when it is turned clockwise, and decreases when it is turned counterclockwise.
The highest rotation speed of chainsaw engines varies from 11,500 to 15,000 rpm. Higher speed can be dangerous for the engine and is simply not provided by the ignition. Therefore, the maximum speed can be determined by the occurrence of ignition interruptions. If they appear, turn screw H slightly counterclockwise.
Re-check at idle
After you have adjusted the acceleration and maximum engine speed, be sure to re-check the operation of the chainsaw at idle. When the carburetor is correctly adjusted, the following conditions must be met:
- at idle, the chain should not move;
- the engine should pick up speed quickly;
- The engine should operate like a four-stroke engine.
If the operation of the chainsaw does not meet at least one of these conditions, the adjustment procedure (except for the basic stage) will have to be repeated again.
Muffler.
You also need to check the muffler. If it is collapsible, then we disassemble it and inspect it, removing all the carbon deposits. In some chainsaw models, the muffler will have to be twisted; there is no other way to check it. The non-removable muffler is dried with a hairdryer after washing. Remember that carbon deposits contain substances that are carcinogens, and dry cleaning, which could result in their inhalation, is unacceptable. When removing the muffler, plug the engine exhaust hole with a clean rag. Do not underestimate this breakdown - the muffler will clog, the chainsaw will lose power or will not start at all. One of the reasons why the muffler may become clogged is the use of a fuel mixture with an excessive amount of oil (the amount of oil is more than the manufacturer recommends), and the use of either oil not intended for two-stroke engines or low-quality oil.
Chain lubrication system
It’s rare that a chainsaw repair manual goes without mentioning malfunctions of the chain lubrication system, which are quite common. They usually manifest themselves in the lack of or insufficient supply of lubricant to the chain and in oil leaks. If the chain turns out to be dry, first of all you need to inspect and clean the channels through which oil is supplied to the bar. Their clogging is a common occurrence.
If there is a significant (small is considered normal) oil leakage, you need to check the tightness of connecting the tubes to the pump fittings. They may fall off or crack. Violation of the tightness of the oil line, in addition to drips, can also lead to insufficient lubrication of the chain. The pump begins to suck in air, which affects its performance. Violation of the tightness is eliminated by replacing the tubes or sealing them with sealant.
Oil pumps come in different designs and can also be driven in different ways. Very often there is no need to change the entire oil pump, it is enough to change its moving part called the plunger; often it is this that fails due to the ingress of a large amount of dirt and sawdust; it simply jams and its edges are licked off. The oil pump is usually driven by a drive sprocket or a special gear on the crankshaft.
The most serious failure of the lubrication system is cracks in the oil pump housing. In this case, it will have to be replaced.
Chain brake
Failure of the chain brake to operate may occur due to contamination of the underframe space and the brake band with sawdust or grease. This also leads to tape wear. In the first case, you need to clean the under-axle space, in the second, replace the brake band.
If you have a brushcutter on your farm - use, maintenance and repair - this will help you. Moreover, you can make your own lawn mower from a chainsaw, thus unifying the tool.
Chainsaw maintenance
Before each start of the chainsaw make sure the chain is in good condition, its teeth are sharp and its tension is normal - without sagging, but not too tight, so that it can be pulled slightly away from the blade.
Sharpening of the chain is carried out both using a special machine and manually using a file and a template for a specific chain tooth pitch. In any case, the instructions for your product contain all the necessary information on sharpening the chain.
After each use of the saw, it must be cleaned. The chain, saw blade are cleaned (sawdust is removed from the chain groove), and the air filter. The saw body and engine air cooling fins, as well as other cracks and grooves, should also be freed from inevitable sawdust. After using the saw, you should turn the blade over so that it wears evenly, and also lubricate the blade sprocket located in the front part (if there are grooves for lubrication).
After a week of regular use you should:
- check the spark plug for the correct gap, make sure there is no deposits on the working elements of the spark plug;
- inspect the saw blade for the appearance of burrs in the places where the chain passes and, if any, remove them with a file. It is also necessary to check whether the geometry of the saw blade is broken - in case of bending and other damage, the blade must be replaced;
- Check the functionality of the start key and other controls.
Before long-term storage of the chainsaw, you must empty the fuel tank and oil container! And yet, the chain and bar must be stored separately, since together they rust, apparently forming an electrochemical couple.
A chainsaw has long been not a luxury, but a necessary tool for those who have a summer cottage or home ownership. But, like any other equipment, this tool tends to fail, despite its simple design.
The classification of main faults includes:
- complete lack of engine starting
- engine starts and stalls
- unstable operation of the tool
- stop work under load
- loss of power.
If the chainsaw does not start at all, the reason may be the following:
- Manufacturing defect
- Lack of fuel
- Problems starting the ignition system
- No spark from spark plugs
- Poor fuel mixture
- Carburetor clogged
- Problems with high voltage wire
- No compression.
Why does the chainsaw start and stall, what to do in this case? The reasons for this need to be examined in detail.
The reason that a chainsaw may stall immediately after the factory is due to a malfunction of a certain piece of equipment.
- The most common reason why a chainsaw starts and stalls may be a low fuel level in the tank. This can be confirmed by the tool stopping when tilted, when fuel residues accumulate in a certain place in the fuel tank. If the fuel is of poor quality, problems with the operation of the chainsaw may also arise; in this case, it needs to be completely replaced.
- A clogged breather, which significantly reduces fuel flow to the engine.
- Insufficient contact of the wire cap with the spark plug, which leads to strong heating of the spark plug insulator. Deterioration of contact may occur due to mechanical shear or carbon deposits.
- Broken spark plugs.
- The muffler is clogged, due to which the exhaust gases are deteriorated, leading to the engine stopping. For this reason, the chainsaw may start and stall at idle. Sediment in the muffler can also appear due to low-quality fuel or improper use of the tool.
- Poor carburetor adjustment.
- Piston group failure
- Problems with the fuel filter or pump. In this case, gasoline may leak through the pump or flow poorly through the fuel filter to the carburetor. As a result, the chainsaw starts and stalls as the speed increases.
- Air filter dirty. Problems with this piece of equipment lead to the fact that, with increased loads on the engine, it simply cannot cope with them due to blockage and stops. A similar result is also obtained with increasing speed.
- Short circuit due to lack of or insufficient lubrication, as well as a problem with the chain brake.
Why does a chainsaw have trouble starting and stalling?
If the equipment starts poorly “on cold”, the problem may be a lack of compression, i.e. The rings are worn out due to long service life and need to be replaced. Sometimes the reason that the engine does not start well when it is not warm is a problem with the muffler, as well as poor contact between the spark plug and the wire.
Also, reasons for poor starting may be wear or damage to the gasket or rubber cuff in the accelerator pump of the carburetor, which causes additional air flow, leading to an increase in saw speed.
Troubleshooting
The operation of the equipment must be correct, with periodic inspection of the component elements to prevent damage. To troubleshoot problems, you need to check all components of the equipment to ensure they are functioning.
If the chainsaw starts and stalls, the cause can be eliminated on your own. If it is a lack of or incorrectly prepared fuel mixture, this must be corrected. For prevention, when the chainsaw is idle, you should always drain the remaining fuel.
It is necessary to periodically check the spark plugs. In this case, you should remove carbon deposits that are clogging the connection gap, and also check the tips for the presence of fuel. Another cause of problems with spark plugs can be that they get wet with gasoline. To do this, they need to be removed, wiped with a rag and left to dry. Faulty spark plugs are replaced.
If there is no spark between the spark plug and the high-voltage wire, but there is a good connection between them, it is necessary to replace the ignition unit.
A clogged muffler is a common cause of a breakdown in which the chainsaw starts and immediately stalls. To eliminate the malfunction, you need to dismantle the muffler and clean it of carbon deposits using sandpaper or a special chemical solution. If the chainsaw model is non-separable, chemicals are poured into the system and left there for several hours, then it is purged.
The carburetor needs to be adjusted if the chainsaw stalls at idle. Fine tuning is a rather labor-intensive process, so it is usually done in service centers. But, on some models there are elements for adjusting it; just turn the bolt half a turn to increase the speed of the chainsaw, and the problems will be eliminated. If the jets, injectors, channels and filters are clogged, it is necessary to disassemble and clean the entire carburetor. When oil seals, gaskets, and cuffs wear out, they must be replaced to prevent air leaks.
If problems arise with the fuel or air filter, it is necessary to replace the fuel pump or clean the air filter.
If the breather is clogged, you need to clean it with a regular needle.
When a chainsaw starts and immediately stalls, the reason may lie in improper operation of the chain. To troubleshoot problems, check the presence of oil in the chain lubrication tank, as well as the oil drain tube for ruptures or blockages.
When inspecting the piston group, you should pay attention to the cylinder and, if necessary, replace it or the piston. You can bore the cylinder to fit the dimensions of the new piston. If the piston and cylinder are normal, you should pay attention to defects in the piston rings and the need to replace them.
Among other things, you should monitor the service life of parts indicated in the product passport, which include the drive sprocket, tire, chain, part of the anti-vibration system, and replace them in a timely manner.
If the tool is idle for a long time, it is worth checking the condition of the fuel line. If the tube is cracked, you will have to replace it with a new one.
Owners of chainsaws sometimes have to deal with the fact that the saw, for no apparent reason, stops working normally. In our article we will try to figure out why the chainsaw stalls in various operating modes, as well as describe how the malfunction can be diagnosed.
The situation in which a chainsaw starts up when cold, but may stall while warming up, is familiar to many who deal with them. The main reasons for this behavior of the saw are as follows.
You can check the ignition coil using a multimeter or by replacing it with a known good one. Checking the primary and secondary windings with a multimeter is carried out in resistance measurement mode. The resistance of the primary winding, the working coil, is 1 kOhm - the secondary is 4 kOhm.
Why does a chainsaw stall under load?
In some cases, the chainsaw is unable to work normally when under load and simply stalls. A common reason for this behavior is incorrect air leakage through the crankshaft seals or carburetor gasket. This behavior can also occur due to a leak in the carburetor.
It is best to diagnose the cause and eliminate the fact that the chainsaw starts and stalls under load at a service center, since a special tool is needed to check the tightness of the carburetor and engine crankcase.
A saw that is unable to operate under load will also be unable to maintain idle speed. They will "float". Diagnostics begins with checking the crankcase and carburetor for leaks. If air leaks are detected through the crankshaft seals, they must be replaced. If air leaks are detected in the carburetor, the cause can be eliminated by installing a repair kit of gaskets.
Only after the above actions have not yielded results and the engine crankcase and carburetor are sealed, can you begin to adjust the carburetor.
The reason for this algorithm is as follows: if air leaks from the crankcase are not eliminated, but the carburetor was simply adjusted to ensure 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 becomes frayed, the saw will idle unevenly and will not operate at all under load.
Owners of household chainsaws HUSQVARNA 137 and HUSQVARNA 142, in case of any deviations in engine operation from the norm, should first check the pulse hose, since this is considered the most common cause of breakdown of these chainsaws.
A video showing how to replace a defective impulse hose on a HUSQVARNA 142 chainsaw with your own hands can be viewed below. It shows step-by-step the process of disassembling the saw, shows the impulse hose and outlines the consequences of its improper functioning HUSQVARNA 142.
Why does the chainsaw not pick up speed and stalls?
If the chainsaw is unable to gain speed a minute after starting or stalls when the gas trigger is pressed, most likely the carburetor or engine crankcase is leaking. As in the previous case, the problem can be solved by checking for leaks and adjusting the carburetor.
If your chainsaw does not pick up speed and stalls after it has been running normally for about 5 minutes, the cause may be a defective fuel tank breather. The vacuum created in the fuel tank during operation of the tool does not allow the engine to receive the necessary amount of fuel for its normal operation, and for this reason it will be unable to gain speed 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 again work normally for about five minutes, after which it will stop picking up speed or stall.
The reason that the chainsaw does not pick up speed may also be excessive carbon deposits in the muffler, which makes it difficult to release exhaust gases, thereby reducing engine power and speed.
If you want to check the tightness of the crankcase, but do not have a special tool, you can use the following testing method.
Algorithm for checking the crankcase for leaks
- Remove the side cover and bar from the chainsaw.
- Unscrew the spark plug and insert a string with knots into the cylinder through the spark plug hole, thereby stopping the movement of the piston and crankshaft.
- You can use an old cord from a starter as a cord with knots, tying knots on it every 3-5 cm.
- Unscrew the chainsaw drive sprocket.
- Remove the oil pump cover and the pump itself.
- Remove the starter from the chainsaw.
- Unscrew and remove the flywheel.
- Remove the carburetor.
- Using a syringe, pour gasoline into the crankcase through the hole under the carburetor in the cylinder, while observing the crankshaft seals. If gasoline flows through them, it means the seals have become unusable and need to be replaced with new ones.
- It is better to entrust the installation of oil seals to professionals.
An indirect sign of crankcase leakage is oil leaks in the area of the seals.
Why does a chainsaw start and immediately stall?
The chainsaw starts and immediately stalls; the reason for this behavior may be hidden in the carburetor. A malfunction of the fuel pump or a malfunction of the main fuel jet may cause this behavior of the saw. The inability of the chainsaw to operate after starting requires a full diagnosis at a 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 leak 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. At medium stages of air leakage, the engine will stop idling and will become very hot during operation. A strong air leak will make it impossible for the saw to operate; it will start and immediately stall.
In parallel with 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 incorrect operation that irreversibly lead the saw to the most severe consequences, for example, melting of the piston, jamming of the crankshaft.
Malfunctions leading to improper operation of the chainsaw
There are a number of malfunctions that must be taken into account when diagnosing, since they can lead to interruptions in the operation of the saw.
- Wear of crankshaft bearings. If the crankshaft bearings are worn out, runout will inevitably appear on the main shaft where the flywheel is attached. In such a situation, it is impossible to adjust the gap between the flywheel and the ignition coil, which leads to interruptions in spark formation and unstable operation of the chainsaw.
- Impulse channel is dirty. The pulse channel serves to ensure the operation of the fuel pump; accordingly, its contamination will lead to improper operation of the pump, which will make it impossible for the saw to operate (it will start and immediately stall).
- CPG wear. As a rule, with increased wear of the CPG, a decrease in compression in the chainsaw engine is observed, which will certainly affect its ability to develop speed.
- Dirty fuel and air filters.
Summing up
When the first signs of improper operation of the chainsaw appear, it is worth carrying out a full diagnosis. To avoid damage to the saw as a result of improper maintenance, it is better to entrust the work of identifying and eliminating engine malfunctions to professionals. And most importantly, you should not use a chainsaw with minor defects, as this will lead to even bigger problems.