Frequent malfunctions of Husqvarna 236-240 chain saw
If the engine cannot be started, the following steps must be taken in sequence:
Location of air filter and spark plug.
- Check if there is petrol in the tank.
- Replace the fuel if it has been stored for more than a month.
- Check the fuel filter. Disconnect the hose from the carburetor and observe the trickle. If gasoline is flowing freely, the fuel filter is not clogged. If the flow rate is insufficient clean the hole in the tank lid or the filter.
- Clean the air filter. The air filter may be removed for a test run.
- Inspect and clean the muffler for carbon buildup.
- Check ignition device for proper operation. If necessary, make repairs to the starter (replace the pulley, spring or cable).
- Disassemble and clean the clogged carburetor.
- Use a tester to check high-voltage wire for open circuit.
- Measure the gap between the flywheel magnets and the ignition module (should be 0.2 mm).
- Unscrew the spark plug and examine it. Measure the gap between the electrodes with a dipstick (normal 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 filled with gasoline indicates a poor carburetor adjustment or a lack of spark. To check for spark, connect the high voltage lead to the spark plug, place the skirt on the cylinder radiator, and pull the starter cord. If there is no discharge between the electrodes, change the spark plug. Carbon deposits on the electrodes indicate a low-quality fuel mixture. The central and side electrodes should be cleaned with sandpaper.
- No compression. The reason. failure of the piston group. Measure compression. First you need to unscrew the spark plug. Then insert the 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 not less than 8 atm. Low reading caused by worn cylinder, piston, piston rings.
Why the chain saw stalls
If the chainsaw starts and stops, there may be a variety of reasons. Visually inspect the machine before trying to repair it.
If the saw stops when working, check the oil and gasoline mixture in the tank. If the fuel mixture has run out, the unit will not operate. In situations where gasoline is still in the tank, it is important to evaluate the quality of the tool before turning it off. If you hear unusual noises and then stop abruptly, be alert.
Caking on the electrodes can also cause problems with tool operation. Visually inspect and clean if necessary.
When the throttle is depressed
If the chainsaw stops when you press the gas, check the muffler and fuel filter. The fuel hoses may be leaking. In some cases it may help to increase the engine speed.
Sometimes checking all the parts doesn’t work, the tool choke, choke when you add gas. If the machine stalls when you step on the gas, there may not be enough fuel to work properly. It is caused by a clogged carburetor or filter.
The problem can also occur if the air filter is clogged with dust. When you step on the gas, the machine stops working. You should not troubleshoot the problem yourself, because each model has individual characteristics.
Insufficient or no lubrication of the chain saw chain can cause a problem. If the chain is dry, the ducts carrying oil to the unit bus should be cleaned. If oil is leaking, there are cracks, defects on the pipes, you need to treat them with sealant.
Under load
In situations where the unit stalls on load, the problem may be with the gas tank or filters. Check the fuel quality and change the filter.
Saw often fails to pick up speed because the mixture in the gas tank has a low octane rating. Not enough power, does not warm up sufficiently, chainsaw quits under load.
Often, the faults of the components lead to the fact that the device under load saps. It is necessary to check for suction of hoses, seals, gaskets. If parts are faulty, you can try to repair or replace them.
In cases where the chainsaw starts and immediately stops, the fuel is not enough, the device does not heat up. The unit should be refueled
It is important to use the proper mixture. Different models are better suited to different types of fuel. It is necessary to read the manual, recommendations, reviews of people whose device works properly
It is necessary to read the manual, recommendations, feedback from people whose unit is working properly.
At idle
In situations where the chainsaw stalls at idle speed, it is necessary to inspect the condition of the muffler. If the part is dirty, the exhaust gases are poorly vented, the engine can’t continue to run, stops.
The saw stops when idling and the carburetor is not properly set. For beginners, it is better to entrust the repair to specialists, as there is a possibility of incorrect adjustment, due to which the tool will not be able to work. A tachometer is needed to adjust the carburetor.
At high revs
If the blower stalls at high RPM, check the gasoline and air filters, check the condition of the fuel hoses
Contaminated air filter can be washed under warm running water
It is important to dry the part thoroughly before installing it so that water does not impair the performance of the tool
If fluid stops flowing through the fuel hose, it is clogged. The part can be cleaned or replaced with a new one.
In those cases, when the saw stalls at high rpm, but the liquid flows through the hose in full volume, and the air filter is clean and serviceable, look for the cause of the breakdown in the fuel filter. Install a new one in its place or clean it.
In some cases, the problem is hidden in the gasoline pump. If the component is worn, fuel starts to leak through the walls. If this phenomenon occurs, it is necessary to install a new pump.
When it is tilted
If the saw does not revolve when tilted, shuts down, stops working, it is necessary to check the fuel level in the tank. If it is not too high, the tilted unit is not getting enough fuel because the fuel pipe is above the mixture level.
The most common causes
A chainsaw is a relatively simple and trouble-free tool, but it can also stop working all of a sudden. The reasons why a chainsaw fails to start and stalls can range from poor-quality gasoline to serious malfunctions. often than not, you can find the cause yourself, but in some cases you’ll have to call a technician. It is important to remember that a faulty chainsaw must not be operated.
Fuel mixture
The most common cause of failure is a problem with gasoline or oil. It is necessary to use the fuel brand recommended by the manufacturer. When choosing an oil it is worth choosing oils with special additives. Usually manufacturers recommend to choose gasoline AI-92 and two-stroke oil.
The second reason is the amount. If there is too little gasoline, the chain saw won’t start, and if there is not enough oil, the tool blade will jam, and then it will stop working.
In addition, it is important to observe the proportions of gasoline and oil. These are listed in the owner’s manual. Most chain saws use 25 ml of oil per liter of gasoline.
Filters
The reason why a chain saw won’t start and shuts down is probably because the air filter is clogged. It does not let air in the volume that the tool needs for quality work. The carburetor is initially set up to mix a certain amount of incoming air and gasoline. If the filter is dirty, the amount of air flowing in decreases and the amount of gasoline stays the same. The result is an enriched mixture.
Also, the filter needs to be changed depending on the time of year:
- A cotton filter is used in the summer when the air is dry;
- Use the HD2 filter when working in winter or in dusty conditions, for example, when logging in large quantities.
If the fuel filter is dirty, the situation is reversed: the amount of fuel decreases and the mixture becomes leaner. Uniform fuel flow is often interrupted and the chainsaw stops when you accelerate.
Spark plug
If you want to find out why a chain saw cuts out when idling, it is worth checking the spark plug. It is an important part of the tool. Several problems can occur with it:
- It can get covered in oil or fuel during start-up. This happens especially often when inexperienced craftsmen do not follow the starting sequence. It is necessary to unscrew the spark plug and let it dry out or screw in a new one.
- The spark plug may be soiled from prolonged use. To avoid this, the plugs should be cleaned regularly with a metal brush or fine-grained sandpaper. It is also a good idea to change the spark plugs regularly.
- There could be a problem with the spark plug tip. This is easy to check: unscrew the spark plug and pull the starter cord. If there is a spark, it means that the spark plug and electronics are fine. If there is no spark, the problem may be due to leaking tubes or a clogged fuel filter.
- The problem may be due to a gap between the magneto and the ignition coil. The size of the gap is given in the instruction manual of the tool, on average it is 0,5-0,65 mm. Problem may arise from working in harsh conditions where the saw is subjected to shocks.
The breather
If the chainsaw does not hold idle rpm, it is worth checking the breather plug. It is a small valve, a hole in the gasoline tank of the saw, through which the air passes. That prevents the vacuum in the tank and the tool works without a hitch. The breather plug can be placed in the tank lid or in the wall.
If the breather is clogged, it creates a rarefied atmosphere inside. That’s why the gasoline can’t get into the carburettor. Sometimes the primer (it’s a pre-fuel pump) pumps a small amount of gasoline into the carburetor and the chain saw starts. But after the carburetor runs out of gasoline, the tool stalls because the clogged breather prevents fuel from passing.
The carburetor
If your chain saw stops, the problem is most likely in the carburettor. This part accounts for about half of all cases.
- Clogged nozzles, ducts, filter, jets. It is often connected with low-quality fuel. the filter is not able to clean the gasoline from impurities and debris and this causes the jets to get clogged. Gasoline stops flowing in the right amount, and even stops flowing at all. The saw is losing power and soon stops working at all. Corrective action would require disassembly and cleaning of carburetor.
- If the chainsaw stops on “hot”, it is worth checking if the rubber sleeve in the booster pump is not damaged. This causes additional air in (suction) which causes the revolutions to rise and the tool soon stops. The problem can be solved by replacing the lip seal. It happens that replacing the cuff does not solve the problem. air continues to “suck”. If it is not possible to determine where the air is coming from, all the gaskets and seals would have to be replaced.
- The booster pump needle begins to drop. Check valve seat leakage may be due to wear or foreign material may have entered. The saw stops starting or shuts down suddenly while working.
- Check valve needle does not seat tightly. In this case, the chainsaw will start to stall when the load increases, it will work poorly and unstably, the plugs will start to flood. Repair the needle will not work, it is better to replace the entire carburetor.
The problem may also be due to improper adjustment of the carburetor.
“Air inlet
This is another common reason why the chainsaw stops at idle speed. The tool does not start or constantly stalls if there is excess air in the air.
- Fuel hoses. Small cracks can form on them if low-quality fuel is used, they can be easily seen by visual inspection. You should also check for a snug fit. the hose should fit snug enough.
- Glands. There are two of them, they are attached to the crankshaft. The oil seals can wear out during use or just from time. Check for leaks with a compressor. This will require closing the inlet on the carburetor and the outlet on the muffler, unscrew the spark plug and supply air under pressure. If you hear a hiss or the pressure does not rise, it means that the oil seals should be replaced.
- Gaskets. They can be damaged by poor quality repairs, during assembly and disassembly of the tool, during installation.
Muffler
Another reason chain saw fails to rev up and shuts down is the muffler. It can become soiled over time. Its appearance is especially promoted by low-quality gasoline and oil, as well as the use of too much oil in the mixture or excessive lubrication. Carbon deposits block the gas from escaping and cause the saw to overheat.
During operation, the chain can simply jam, after which the saw shuts down. There can be several causes:
In all cases, the tire on the chain saw is dry.
Cylinder piston group (CPG)
This is the most unpleasant and expensive breakdown. The cost of replacing the cylinder head can be as much as half the cost of a tool. It is best to take the saw to a service station and not try to disassemble it yourself.
Doing a diagnostic
The situation when the malfunction makes itself known, and the saw stops working, often puts the owner in a difficult situation. In a good way, the unit should be given to the repair to find out exactly why it does not start, and then trust the repair professionals. However, not all failures are fatal, and even a person who is far from machinery can cope with them.
The first thing you should do is to make a diagnosis of the device. It consists in a close inspection of the main parts of the saw, namely:
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What to do if the chain saw won’t start even afterwards?
If the initial inspection did not give anything or defects were eliminated during the search, and the chainsaw and continues not to start, then you need to look for more serious causes. The best way to find and repair such malfunctions is to call a service center. However, if you have experience, you can find and fix them yourself. What to diagnose and check?
In the first case, checking the compression in the cylinder will clarify the condition of the cylinder-piston group (CPG) chainsaw does not want to start in the cold. For this you need a compressometer. The gauge is screwed in place of the spark plug and the engine is idled. The readings are used to indicate the condition of the cylinder block. In the absence of a compressometer, you can determine the compression in a cylinder at a glance, as follows:
It is possible to check the compression in a cylinder by placing the finger on the spark plug hole and jerking the starter
If you feel your finger strongly retracting into the spark plug hole, then there is nothing wrong with compression. If there is no vacuum in the compression chamber, this indicates a malfunction. The cylinder-piston group needs a more detailed examination, which will give an idea of the condition of the piston and cylinder, piston rings and bearings.
Not start the chainsaw in the cold can also be due to lack of compression in the engine crankcase. The main reason is that the gasket between the cylinder and crankcase is damaged. It is quite easy to identify the lack of compression:
- Disconnect the upper tube from the carburetor;
- Pour gasoline into the regular cap;
- We dip the removed tube into the fuel;
- Pull the starter a few times.
If fuel is sucking out of the cap when the chainsaw starter starts, there is nothing wrong with the compression. If not, check the gasket.
If the fuel retracts, everything is fine. the gasket is intact. If not, you will have to buy a repair kit and make a replacement. How to do it see the video, why the Chinese chainsaw does not start:
Starting the tool can be complicated by improper operation of the carburetor or its failure. It often happens that while you are sawing the screws get loose and air gets sucked into the cylinder. Check that the carburetor is securely fastened. Inspect it for fuel leaks. There could be many reasons for the malfunction. It is possible to accurately determine the defect, fix it and make fine adjustment of the carburettor only in the service center.
By going through the step-by-step defectovki chainsaw engine, you can find the fault, fix it yourself and successfully start your working tool. Do not undertake work that you are not sure about. Have the cause of the problem found and repaired by an expert in the service center.
Troubleshooting Husqvarna 236 chain saw
According to official statistics, its 5 most vulnerable systems are considered:
Manifestations of faults of the first group:
- the engine does not start or does not function stably;
- starts with periodic glitches;
- does not hold idle;
- it fumes and doesn’t develop the tractive force specified by the manufacturer.
In addition to the above mentioned, there is another problem, on which we will dwell in more detail.
Engine stalls when throttle: causes and remedy
All of the above causes can be corrected as follows:
- cleaning of the working organs related to fluids or air working environment;
- external inspection of the listed parts for malfunctions;
- replacing old parts with new ones.
Proper carburetor adjustment is very important for stabilizing the working stroke of the chain saw, and it is possible to do it at home.
The motor stalls when pressing the gas: the causes and their elimination
The solution to all of the above causes can be summarized as follows:
- Cleaning the operating elements related to fluids or air working medium;
- external inspection of the listed parts for malfunctions;
- replacing old parts with new ones.
Correct carburetor adjustment is very important for stabilizing the operating stroke of your Husqvarna chain saw, and it can also be done at home.
Adjusting the carburetor “Husqvarna” 236 with your own hands
The question of how to adjust the carburetor of chainsaw model 236, is quite relevant. The considered modification of a chainsaw has a carburetor from the brand “Zama”, which design contains a gas pedal pump. Any situation accompanied by unstable operation of the engine, formation of abundant exhaust and a sharp increase in consumption of fuel mixture, indicates the need to readjust it.
It is made in several stages:
- turning the screws H and L clockwise;
- setting of idle and maximum revolutions. turning the jets clockwise will increase them. You will need a tachometer and an operating manual with nominal engine parameters.
If the engine works evenly under load and at idle, the chain is motionless at idle. the carburetor readjustment was successful.
Modesty is an advantage of original “Husqvarna” chain saws, the producer country of which is Sweden. Unfortunately, the same can not be said about the Chinese fakes, which are not predictable in operation and repair.
How to adjust the carburetor of a Husqvarna 142 chain saw
The carburetor on your Husqvarna 146D must be adjusted while the engine is warm. Pay attention to the condition of the air filter, which, if necessary, will need to be cleaned and make sure it is not clogged. Adjusting the carburetor of the Husqvarna chainsaw one hundred forty-two with your own hands is done with the help of three screws:
Turn the low and high revolutions control screws clockwise to the limit, and after the peak is reached, turn them in the opposite direction, one and one-half turns. Chainsaw starts and stops, Husqvarna 142 chainsaw piston video. When working at idle, the chain for the Husqvarna one hundred forty-two chainsaw should be stationary. Check at maximum rpm.
Avoid most malfunctions and expensive repairs by following the manufacturer’s instructions and recommendations and by using original spare parts for your Husqvarna 142 chain saw.
Husqvarna Saw Disassembly Algorithm
The Husqvarna chain saw disassembly process is simple. In order to do everything correctly and not to break parts of the body or the CKD, it is necessary to disassemble in the following order:
- Top cover.
- Chain and chain brake cover.
- Starter.
- Handwheel and clutch.
- Front crank.
- The carburetor.
- Oil pump.
- Engine.
Depending on the model of the Husqvarna, the disassembly procedure may be slightly different.
Important: Before you start to dismantle the chain saw, you must first clean it. sawing produces a lot of chips and wood dust that can get into the interior of your Husqvarna chain saw if you disassemble it.
To remove the side cover and saw headset
The side cover, also called the saw chain brake cover, is held in place with two thirteen-point nuts.
After unscrewing the nuts, the cover is removed from the guide rods and the guide bar and chain can be removed from the chain saw. Some models of Husqvarna saws have a special mechanism that allows to dismantle the cover and the saw headset without using special tools.
Starter
The starter is located on the right side of the Husqvarna and is held in place by several screws. By unscrewing that, it is easy to remove the starter and thereby gain access to the flywheel and ignition coil.
Removing the flywheel and clutch
In order to unscrew the flywheel nut, unscrew the spark plug and install the piston stopper instead.
If you do not have a special stopper, you can use an old chain saw starter cord instead. You need to tie knots on the cord at a distance of 2-3 cm, and then, using a screwdriver, insert it through the spark plug hole inside the cylinder. The lanyard will limit the piston stroke, thereby preventing the crankshaft from turning and protecting the piston from damage.
Once the piston stopper is in the cylinder, you can unscrew the flywheel nut. After the nut is undone with a hammer and a mallet of soft material you have to make one sharp blow with the mallet on the flywheel mounting shaft. This is necessary to remove the flywheel from the shaft, t. к. the design involves installing and tightening this element with a high torque.
To learn more about how to remove the flywheel from a Husqvarna chain saw, as well as how to completely disassemble the saw, watch this video. The wizard explains the entire process step by step and demonstrates all the necessary tools:
In order to unscrew the clutch you need a special wrench. If there is no wrench, it can be made from an old twenty-two head by grinding it in a certain way with an emery.
The clutch is left-hand threaded and unscrewed in a clockwise direction.
Do not try to unscrew the clutch with a hammer and chisel, as some experts advise. Using these tools, you risk breaking the clutch housing and increasing repair costs. It can also damage the crankshaft bearings.
Front handle
Removing the front handle of the Husqvarna is easy enough, t. к. it is fastened to the shock absorbers with screws.
air filter and carburettor
To remove the carburetor, you must disconnect the fuel hose and choke rods from it, it is convenient to do this after removing the air filter, which is installed immediately behind the carburetor and is held by two 10 nut. After the air filter is removed and the fuel hose and rods are disconnected, simply pull the carburettor toward you and remove it from the studs.
Use tweezers and medical clamps to remove the carburetor.
Oil pump
On the Husqvarna, the oil pump is installed on the right side of the chainsaw. it can only be removed after unscrewing the clutch. No special tools are required for removal.к. the screws are made to fit a normal Phillips screwdriver. After the screws are unscrewed, it is necessary to lift the pump and disconnect the oil hoses from it.
Engine
To remove the engine on a Husqvarna chain saw, after removing the carburetor, clutch, flywheel, and muffler, you must remove the four screws that secure it to the housing.
Once the engine is removed, you can unscrew the ignition coil from it, not forgetting to first disconnect the wires running from it to the ignition switch. The coil can also be removed as soon as the starter is removed.
How the mechanism is set up
Almost all tools, and foreign (Husqvarna, Makita, STIHL, Partner 350), and Chinese chain saws, and domestic (Druzhba, Ural), are arranged similarly. Therefore, to find the reason why the machine does not start and stops is not very difficult.
There are four elements in which problems can occur:
- Fuel, for which the carburetor is responsible;
- Lubricant;
- Air, which comes through the air filter;
- The spark, the quality of which depends on the ignition unit.
All of them depend on one another and interact with one another. If one element is not working properly, the saw stops working.
To begin with, all tools start differently. hot and cold. There are two frequently used mechanisms for this process.
Always check what is written in the owner’s manual. It says to make sure that the emergency stop brake is engaged when you turn it on. But it is much more difficult to start a saw with a brake, so sometimes it’s better not to use the brake.
As you can see from the manual, inside the body there is the fuel tank and the engine and outside there is the saw part (guide bar with chain), the handle and the starter.
First you need to figure out how the tool won’t start. For example, the saw starts, but immediately stops working, or loses power, the quality of the cut.
Maybe the malfunctions are caused by a problem with the engine. But I would not recommend to disassemble it right away. It is better to look for a problem from the simplest version.
It is very important to consider the quality of the fuel. If the mixture is prepared incorrectly or has deteriorated over time, even such reliable tools as Ural or Husqvarna 145, will not work. The manual is sure to indicate the proportions and special oil specifically for your chainsaw.
Another common problem. during the start the user fills the spark plug. It should be inspected, if it is completely dry, it means that the fuel is not passing into the cylinder.
If you see black carbon deposits or a lot of fuel, the carburetor may not be adjusting the fuel flow properly.
If your power tool starts but immediately stops, the problem is in the carburettor jets or fuel filter. They may be clogged.
To check if the breather hose is intact, disconnect the fuel hose from the carburetor and check if fuel mixture is leaking.
If the saw won’t start on hot, the problem may be in the muffler. Sometimes it gets clogged by the exhaust.
Quite often saw breaks down because of too little chain lubricant. This can happen if passages are blocked or if an oil pipe leaks.
Also check the hose connections to the oil pump connection to see if they are leaking.
It is very bad if the failure is in the cylinder. On examining it, you might find a bump or splinter, which might be the cause of the problem.
Getting the tool working again
To restore the operation of the saw, no matter the brand Ural or STIHL, you need to know the location of the failure.
First check and change unsuitable fuel mixture. If the saw still fails to start, then check the following points.
The problem is the spark plug. pull it out and dry it. Never pierce it, because this will cause the part to malfunction. After 30 minutes of drying, you can insert the plug back in, checking beforehand if there is any fuel left in its place.
In addition, the spark plug can simply break, so it’s better to have a spare to rule out the cause.
Another reason for the tool not starting well and stopping is bad contact between the spark plugs and the high-voltage wire. If everything is okay here, but there is still no spark, the ignition unit itself may be broken. The only way to solve such a problem is to replace the breather plug.
You should check and clean the air filter from time to time. If you have not checked it since the purchase, it may be clogged with dust and cause a malfunction.
On models like the STIHL 180, Ural and Partner 350 the breather plug often gets clogged and can be the reason. To clean it, it can be cleaned with a sewing needle.
The muffler on the STIHL 180, Druzhba, Ural and Husqvarna 142 models is sometimes clogged and should be checked and cleaned.
If the carburetor is the problem, it is not a good idea to give it a try and repair it without first fixing it. It is best to call in a specialist.
If after checking and correcting the above mentioned problems your chain saw still does not start, the problem is most likely in the cylinder group.
When you see signs of damage or chips in the piston or cylinder, they must be replaced.
If the chainsaw is malfunctioning because of leaking tubes, it is most likely that the chain is not getting enough lubricant. To fix the problem you just replace the tubes and put sealant on the connections.
Parts of the mechanism do not last forever, so they must be replaced periodically. To find out how long a part lasts, you need to look in the manual.
The saw stops when you turn it
In the horizontal position the fuel tube is at the bottom of the tank, but if you tilt the tool, the fuel will not be able to completely cover it. This is the reason why the chainsaw stops working when it is tilted, because the tube levitates in the air and the right amount of mixture does not flow to it.
If you have noticed that the chainsaw does not start without warming up, but stops after warming up. And it will not start until it cools down, then here, there may be several problems.
First, there may be a leak in the hose, packing or gasket somewhere. Second, inspect the muffler for fouling. The third reason is in the cylinder-piston group (CPG), whether there are any scuffs or irregularities.
Sometimes you need to adjust the carburetor. Another important cause of malfunction, is the ignition coil. When it fails, the spark is lost or becomes very weak, not enough to ignite the fuel mixture.
There are cases when the master is trying hard to engine, then on the cold, then on the hot, thereby pumping fuel. Here you need to take hold of yourself, move the choke to a “hot start” and gradually start the tool. In doing so, bring the rpm down to near idle and 40-45 seconds it warms up.
The saw stalls after releasing the throttle
Here you need to adjust the carburetor and check whether there is no strong air drain.
The most common chain saw breaks we’ve already looked at. You just have to hope that your saw does not break down. But even rugged models like STIHL and Partner can sometimes go wrong.
Don’t rush to the service, use my tips first, it will save you a lot of money.
Share this article with your friends on social networks if you found it interesting. And I bid you farewell. Good luck and see you on the blog!