It often happens that during prolonged operation, the walls of the exhaust pipe are covered with soot, which prevents the free exit of exhaust gases.
In this case, remove the muffler (if possible) and wash it with detergents, then dry it thoroughly with a hair dryer.
ATTENTION! Nagar contains carcinogens. During dry brushing, it can get into the lungs, which poses a threat to your health.
The cause of soot, as a rule, is the wrong ratio of gasoline to oil or the use of low-quality and incompatible oil.
Carefully read the operating instructions for the chainsaw to prevent this from happening in the future.
The wear of the cylinder and piston, the appearance of scratches and scuffs on their surface, the wear of piston rings or crankshaft bearings are all very serious damage. As a result, they lead to a pressure drop in the cylinder. In this case, it will be very difficult to start the engine.
Without disassembly, you can check the condition of the CPG as follows. Remove the muffler and look through the window that opens. Part of the surface of the cylinder will be visible. To obtain information about the state of the CPG, the compression in the engine is measured using a compression gauge, which must be installed in the spark plug hole. Turning the crankshaft (possible with a starter), measure the readings of the device. Compressometer readings should not be lower than 8-9 kgf / sq. cm (or 0.8-0.9 MPa).
If there is no compression gauge, you can check the presence of compression by eye by simply plugging the hole in the spark plug socket with your finger and pulling the starter, as shown in the photo below:
The cause of low compression may be coked piston rings or wear.
Each operating manual indicates the need to monitor the condition of the chain lubrication system.
Usually, system malfunctions occur due to clogging of the channels through which lubricant is supplied. With a slight leakage of oil, you can continue to operate. But if the oil leaks are large enough, then you need to check the tightness of the connection of the pipes to the pump fittings. You can fix the leak with a sealant or by replacing the tubes.
You should also pay attention to the condition of the oil pump. If there are cracks in its body, it must be replaced.
VIDEO
If the chain brake does not work, the cause may be contamination of the brake band with grease or sawdust with wood resin or the undercover space.
You can fix the problem by cleaning the dirt and replacing the brake band.
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Prices for chainsaws are falling and this makes them more popular and affordable not only for professionals, but also for ordinary, let's say, amateurs. However, a common dependence - the lower the price, the less reliable the device and more often there are malfunctions, is also relevant for a chainsaw. But for chainsaws of any price range, most problems can be avoided with proper operation, care and timely maintenance of equipment. But from the breakdown of a chainsaw, as well as any other equipment, no one is safe. Therefore, it is proposed to consider the main types of chainsaw malfunctions, methods for their diagnosis, elimination and repair .
All the main malfunctions of chainsaws can be divided into two main categories:
Here are the various violations in the operation of the chainsaw engine, which occur most often. The main such malfunctions are reduced to the following symptoms:
the engine does not start (rather generalized and the reasons can be quite different);
starts, but often stalls;
does not develop power, i.e. runs fine at idle, but stalls or “chokes” under load.
It smokes a lot, power drops.
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 there is actually no breakdown. For example, if you do not start the chainsaw correctly and pull it for a long time on the suction, then 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 “choke closed” position. Then you need to pump the mixture into the carburetor, if a fuel priming pump is available. Pull the starting handle until the resistance of the engine 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 it is necessary to move the lever to the half-gas position or simply to the working position and then continue to start the chainsaw in this mode. For many chainsaws, "semi-gas" is fixed automatically when the air damper is pulled out. Some models have an ignition key switch, it is important to make sure that it is turned on.
If the engine won't start, the first thing to do is remove and inspect the spark plug. There are cases when the plant in the cold season, fill the combustion chamber with fuel. Then, too, you need to unscrew the candle, dry the combustion chamber with an idle plant, clean the candle, screw it in and repeat the start. It is advisable to immediately check for the presence of a spark - we put a cap with a high-voltage wire on the unscrewed candle, put it on the cylinder and pull the starter. We visually observe a frequent blue spark - good. We screw the candle into place and start it. If there is no spark, change the spark plug and try again. Again, no - we check the connection of the high-voltage wire to the candle, the coil and the ignition system.
In general, the condition of the candle can be used to judge the type of malfunction.
Dry. Most likely, the fuel mixture does not enter the cylinder. It's not the ignition system, so the candle is twisted back and the fuel supply system is checked.Wet, heavily splattered with fuel. The reason for the excess of the fuel mixture lies either in violation of the rules for starting, as described above, or in improper adjustment of the carburetor.Covered with black soot. This may indicate the use of low-quality oil, an incorrectly adjusted carburetor, or an incorrectly calculated ratio of gasoline and oil. The candle should be washed, cleaned of soot with a sharp object (awl or needle), wipe the electrodes with a sandpaper and place in place.When checking the candle, you need to pay attention to the gap between the electrodes: from 0.5 to 0.65 mm is considered normal. A damaged or worn gasket must be replaced.
A properly adjusted chainsaw carburetor ensures that the chainsaw operates efficiently at full power with the most economical fuel consumption.
The need to adjust the carburetor of a chainsaw occurs infrequently, since the adjustment is initially carried out by the manufacturer to achieve optimal operation. The adjusting screws are designed to more accurately adjust the chainsaw carburetor if necessary.
When and why does this need arise?
Among the causes of violation of the fixation of the adjusting screws, the most common are the following:
Strong vibration or damage to the protective cap. This rarely happens, 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 a damaged air filter, poor quality gasoline, or due to dross formation. In this case, in addition to adjusting the carburetor, flushing it cannot be avoided.
What signs indicate the need to adjust the chainsaw carburetor?
Firstly, the engine does not start, or it starts, but immediately stalls. This is most often due to a lean fuel mixture.
Secondly, a significant increase in fuel consumption and exhaust emissions.An increase in exhaust indicates that the fuel does not burn completely, which means that the cause may be a supersaturation of the fuel mixture.
The chainsaw carburetor adjustment scheme may differ slightly depending on the manufacturer (the process for adjusting the chainsaw carburetor of a particular brand and model is described in detail in the instruction manual), 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 set low speed;
"H" is needed to adjust the top speed;
"T" is needed to adjust the idle speed (for models with one screw, only it is present).
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 flat 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. Following the manufacturer's instructions exactly will help you avoid engine damage.
The chainsaw carburetor tuning process consists of two stages: basic (engine off) and final (running warm engine).
Slowly turn the maximum and minimum speed adjusting screws (H and L) clockwise to the stop, then back out counterclockwise 1.5 turns.
Before this adjustment step, it is necessary to warm up the engine for 5-10 minutes, avoiding high speeds.
By turning the idle speed 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 idling, tighten the idle speed screw clockwise. If the chain is driven, turn the screw counterclockwise.
To complete the adjustment of the chainsaw carburetor, it is necessary to check the engine for acceleration and maximum speed.
To check the operation of the engine for acceleration, gently press the accelerator and make sure that the engine quickly picks up speed from idle to maximum (from 2800 to 11500-15000 rpm - depends on the brand and model of the saw). If the engine speeds up slowly, slowly turn screw L counterclockwise (no more than 1/8 turn).
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 rotational speed of chainsaw engines varies from 11,500 to 15,000 rpm. A higher speed can be dangerous to the engine and simply does not provide ignition. Therefore, the maximum speed can be determined by the occurrence of interruptions in the ignition. If they appear, turn screw H slightly counterclockwise.
After you have adjusted the acceleration and maximum engine speed, be sure to recheck the operation of the chainsaw at idle. With a properly adjusted carburetor, the following conditions must be met:
at idle, the chain should not move;
the engine should quickly gain momentum;
engine operation should resemble a four-stroke engine.
If the operation of the chainsaw does not meet at least one of these conditions, the adjustment procedure (with the exception of the basic stage) will have to be repeated again.
You also need to check the muffler. If collapsible, then disassemble and inspect, remove all soot. In some models of chainsaws, the muffler will have to be twisted, there is no other way to check it. The non-separable muffler is dried with a hairdryer after washing. Remember that soot contains substances that are carcinogens, and dry cleaning, as a result of which their inhalation is possible, is unacceptable. When removing the muffler, plug the engine outlet 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 a muffler can become clogged is using a fuel mixture with too much oil (more oil than the manufacturer recommends), and using either non-2-stroke oil or poor quality oil.
A rare chainsaw repair manual does not mention chain lubrication system failures, which are quite common. They usually manifest themselves in the lack 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 tire. Their clogging is a common occurrence.
In case of significant (small is considered normal) oil leakage, it is necessary to check the tightness of connecting the pipes to the pump fittings. They may fall off or crack. Violation of the tightness of the oil pipeline, in addition to drips, can also lead to insufficient chain lubrication. 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 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 he who fails due to the ingress of a large amount of dirt and sawdust, it simply wedges and licks its edges. 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 are cracks in the oil pump housing. In this case, it will have to be replaced.
Failure of the chain brake may occur due to contamination of the undercover space and the brake band with sawdust or grease. This also leads to belt wear. In the first case, you need to clean the under-cover space, in the second - replace the brake band.
If there is a lawn mower in the household - use, maintenance and repair - to help you. Moreover, you can make a lawn mower out of a chainsaw, thus unifying the tool.
A chainsaw is a worthy replacement for hand saws and axes. Today, this tool is available in almost every household - it is indispensable for arranging a personal plot, construction and repair work. Intensive use and improper care of the tool can lead to premature failure. However, it is not at all necessary for the owner of a chainsaw to immediately contact the workshop - many of the malfunctions that can happen to it during operation can be eliminated on their own.
The main condition for a successful repair is the correct diagnosis. Therefore, in order to determine why the chainsaw failed and, most importantly, how to make it work again, you first need to know the features of its design.
It should be noted that it does not differ in particular complexity, since it includes:
engine (two-stroke gasoline);
functional part (saw bar and chain);
systems that ensure the joint operation of these two components (ignition, filtration, lubrication, etc.), that is, the tool as a whole.
In order to simplify the diagnosis of faults, they are usually divided into two main categories:
engine malfunctions;
malfunctions of other components of the chainsaw.
Most often, failures occur in engine systems, however, other parts of the tool, due to intensive use or improper care, can fail at any time. How to determine exactly where the breakdown occurred? Simple logic will help us with this.
If the problem is in the engine, it will:
do not start;
go deaf;
unsteady work;
overheat;
smoke;
develop insufficient power.
As for all other malfunctions, as a rule, they manifest themselves with a normally running motor.
If the chainsaw won't start, the first thing to do is to check the fuel mixture in the tank. By the way, it must be prepared in the proportions specified by the engine manufacturer, otherwise the tool simply will not start.
After making sure that the fuel mixture is correct and available, the ignition system should be checked. To do this, inspect the spark plug.
Her condition can say a lot:
indicates that the fuel mixture does not enter the carburetor, which means that the problem is not in the ignition;
is the result of an excess of the fuel mixture, which lies either in a violation of the engine start algorithm, or in improper carburetor adjustment;
this is a signal about the presence of low-quality oil in the engine lubrication system, incorrect carburetor settings, or an incorrectly prepared fuel mixture.
If the spark plug is splashed with fuel, wipe it thoroughly after removing it. The fuel supply system should also be cleaned. To do this, it overlaps, after which the starter is turned on. A carbon-covered candle must be carefully cleaned with an awl and emery.
When checking candles, attention should be paid to the distance between the electrodes (the normal gap is 0.5-0.65 mm), as well as the condition of the gasket and the presence of a spark. A damaged or worn gasket will have to be replaced, and the spark can be checked by putting on the ignition cable, connecting the cylinder and spark plug nut, and cranking the starter.
If the discharge does not occur, the candle must be replaced. In the event that a spark does not appear with a new candle, then the problem is in the connection with the high-voltage wire or in itself.
If the fuel mixture does not enter the cylinder, but the spark plug is working properly, this may mean that:
The fuel filter is clogged.
To clean this assembly, remove the fuel hose and check the jet. If it is weak, the filter must be removed through the filler hole of the fuel tank and cleaned or replaced in case of complete wear.
As a preventive measure, it is recommended to replace the fuel filter at least once every 3 months.
This is nothing more than a hole in the fuel tank cap, which is cleaned with an awl.
The fuel mixture is not supplied or supplied in insufficient quantity.
There may be several reasons for this:
the air filter is clogged (in this case, it must be removed, rinsed with water, dried and put back in place);
the carburetor settings have gone astray (which means this assembly must be re-adjusted);
the integrity of the carburetor membrane is broken (it must be replaced);
the carburetor channels are clogged (it must be disassembled and cleaned of all parts and assemblies).
If the chainsaw motor works fine at low speeds, but starts to stall and smoke at high speeds, the problem may be hiding in the muffler.
To check the quality of its work, do the following:
dismantling (with obligatory closing of the outlet);
disassembly (if the muffler is collapsible);
cleaning from carbon deposits using special detergents or by dry method;
drying (using a hair dryer);
reassembly and installation.
Dry cleaning without respiratory protection is not recommended. The carcinogens present in soot will be released into the surrounding atmosphere in the form of dust, the inhalation of which is extremely dangerous to health.
To prevent clogging of the muffler during the operation of the chainsaw, you should carefully monitor the composition of the fuel mixture and the quality of its components.
If the chainsaw engine does not start or cannot develop normal power, it is likely that there is not enough pressure in the engine cylinder to burn the fuel mixture. The reason for this may be the wear of the elements of the cylinder-piston group - piston, rings, bearings, etc. In order to assess the condition of this assembly, it is necessary to conduct a visual inspection of it, after removing the muffler.
For a more complete diagnosis, a compression gauge is placed in the spark plug hole of a two-stroke chainsaw engine. It measures the compression in the engine. Based on the results of the check, one can judge the state of the CPG, however, accurate facts can only be obtained with a complete disassembly of the assembly.
If there are chips or scratches on the piston, it is obvious that it will have to be replaced. The same applies to deformed or broken piston rings - for normal engine operation, they must be fully functional and clean from carbon deposits.
A properly working carburetor guarantees maximum efficiency of the chainsaw, that is, it is possible to develop full power with the most economical consumption of the fuel mixture. The adjustment of this unit is usually carried out by the manufacturer, however, its design provides for the possibility of adjustment during operation.
The fact that such a setting will have to be performed by the owner of the chainsaw is evidenced by:
Strong vibrations or damage to the protective cap.
Depreciation of the CPG.
Clogged carburetor.
Inability to start the engine or its spontaneous stops after starting.
Increased fuel consumption and emissions while reducing engine power.
The chainsaw carburetor is adjusted in strict accordance with the manufacturer's instructions using three special screws that are responsible for the maximum ("M") and minimum ("L") revolutions, as well as idling the engine ("T"). In order to exclude unwanted interference by an inexperienced user in the operation of the carburetor, some manufacturers install only one idle screw.
Carburetor adjustment is carried out in two stages:
Basic (carried out with the engine off).
Finishing (carried out with a running, preheated engine).
For basic adjustment it is necessary to tighten the screws H and L until they stop and turn them back 1.5 turns. Finishing adjustment requires that the engine be warmed up for 5-10 minutes at low speeds.
The final calibration is carried out by turning the idle screw until the minimum engine speed is reached (its operation must be stable and the chain must be stationary). If the engine stops idling, the screw must be turned back, and if the saw chain is still driven, continue to turn it counterclockwise.
Calibration check is done by test:
Accelerations (when you gently press the accelerator, the engine should quickly gain momentum to the maximum rate).
Maximum speed (if there is a misfire, screw H should be slightly loosened).
Idle operation (the chain should not move, and the engine should pick up speed as quickly as possible).
If the owner of the chainsaw is not familiar with the carburetor device and does not have the tool necessary to calibrate it, you should contact a specialist. The carburetor is a very complex unit, so any wrong action can lead to irreversible consequences, such as complete failure of the engine.
If the diagnostics showed that everything is in order with the engine and its systems, then the cause of the malfunction should be sought in other components of the chainsaw. The most common problems are:
starter failure;
improper operation of the lubrication system;
incorrect operation of the chain brake;
saw chain wear, etc.
If the cause of tool failure is not visible to the naked eye, as is the case with an engine, a thorough fault diagnosis must be made and corrected in accordance with the manufacturer's recommendations and safety regulations.
VIDEO
Almost every villager and many cottage owners have chainsaws on the farm. They are easy to use and can be repaired by hand. It is not so difficult to find out the reason why the device does not start, troit, has problems with idling. Despite the varieties of chainsaws, the principles of repair are the same.
Chainsaws are divided by class and purpose.
The purpose of the tool affects the power, weight and dimensions. Chainsaws have three purposes:
Before you start disassembling and repairing the chainsaw, prepare the necessary tools and accessories:
Overalls.
Gloves.
Free space on the table.
Candle wrench with screwdriver.
Chainsaw problems can be of two types:
Malfunctions of the engine, ignition system, fuel supply and exhaust.
Malfunctions of other nodes.
The following indicators will indicate that it is necessary to diagnose the engine:
The tool does not start or starts and stalls.
Works unstable.
It runs at idle, but when under load, the rpm drops or stalls.
Problems of the lubrication system.
The chain brake does not work.
Breakage or wear of the chain.
The star has worn out.
It is necessary to check the appearance of the spark plug.
Take the candle key. Remove the insulating cap with the power cable. Unscrew the candle with the key.
Fuel is not supplied for three reasons:
There is a hole in the fuel tank cap that could be clogged. If this happens, a vacuum has formed that prevents the fuel from flowing out.
The fuel filter is installed in the tank. It gets dirty over time.
Fuel is poorly supplied from the carburetor to the cylinder.
The first two reasons are identified in the same way. To do this, disconnect the hose through which fuel passes from the carburetor. And check how much pressure it flows. If it flows weakly or does not flow at all, then the tank cap is cleaned with a needle, and the fuel filter is replaced. But first you need to drain the combustible mixture and remove the filter from the tank with a wire hook. If fuel flows well from the disconnected hose, then the air filter is clogged or the carburetor is faulty. The air filter affects the flow of air into the carburetor and enriches the combustible mixture. When it is clogged, the mixture is too rich, as air is not getting in. This affects the correct functioning of the engine.
Carefully remove the air filter to prevent dust from scattering. Cover the hole formed in the combustion chamber with a clean cloth.
Blow out the filter and clean with a soft brush. If the filter does not clean, wash it. Put it back after drying.
Before adjusting the carburetor, check that the air filter is clean and that the chain is sufficiently tensioned. Read the instructions. The manufacturer describes how to properly adjust the carburetor. If no instructions are available, locate the three marked screws:
H - screw maximum speed.
L - minimum speed screw.
S - idle speed fine adjustment screw.
Take a screwdriver to adjust the carburetor and proceed.
Basic adjustment. Produced with a cold engine turned off. Turn screws H and L all the way to the right, i.e. clockwise. Then one and a half turns to the left.idle adjustment. Before starting, turn on and warm up the engine. Turning screw S to the right increases the speed, and to the left it decreases.You need to lower the speed and control so that the engine runs stably, without pauses. Watch the immobility of the chain. If the engine suddenly stops, gradually increase the speed. And when the chain is moving, reduce.Checking the engine for acceleration. Gently press the fuel button. An adjusted engine should quickly and confidently gain momentum to the maximum. If the engine lags and runs unsteadily, turn screw L to the left no more than an eighth of a turn.Adjustment of the maximum turns. When the maximum speed is reached, there are interruptions in the ignition. Slowly turn screw H to the left until stability is achieved.After all adjustments, check the operation of the engine at idle. It should work stably when the chain is stationary. If you do not achieve the desired result, repeat all adjustments, excluding the base one.When the muffler is clogged, the exhaust gases have nowhere to go. The saw will not work and start. The design of the chainsaw allows you to remove the muffler quickly. Depending on the mounting method, you may need a hex key or socket wrench.
Loosen the screws. Slightly rocking the muffler, remove it from the studs. Plug the hole in the motor with a clean cloth.
The muffler becomes dirty due to low-quality oil or the wrong composition of the fuel mixture.
VIDEO
Wear and damage to the cylinder-piston group makes it impossible to start the engine.
To find damage, remove the muffler. An exhaust port will open for you, into which you will see part of the surface of the cylinder.
Part of the cylinder in the exhaust port
In addition to the piston, which may not show damage through this hole, inspect the piston ring. If defects are present, then it is necessary to disassemble the entire piston group in order to fully assess its condition. Malfunctions are eliminated only by a complete replacement of the group.
Get a compression gauge. Screw into the candle hole, gently pressing the sealing gum.
Pull the starter, watching the arrow of the device.
The pressure must be at least 8 atmospheres.
If there is no such device, try the folk way. Unscrew the spark plug.
Checking compression in a folk way
Plug the spark plug hole with your finger and pull the starter. If the finger sucks, then there is compression.
VIDEO
Violation of the integrity of the cutting links.
Slots, wear and cracks of rivets and sides of links.
The cutting link has worn out so that it becomes difficult to cut.
Connecting link damaged.
After replacing 3 chains, change the bar and the drive sprocket.
To replace the sprocket, you will need: a spark plug wrench, a piston stopper, a clutch puller.
Remove the cap to access the spark plug. Unscrew the spark plug.
Use the clutch puller to turn the clutch clockwise to raise the piston to top dead center. This can be checked through the spark plug hole.
Screw in the piston stopper instead of the spark plug. If not, then twist a thick bundle of ropes and insert it into the candle hole.
Turn the clutch puller to the right and you unscrew it.
Remove sequentially all the parts of the clutch assembly and the plate with an asterisk. Replace it with a new one.
VIDEO
If the bar is not lubricated or poorly lubricated, the chain and bar will overheat, causing a lot of friction and wear. Check the holes and channels through which the lubricant enters. If they are clogged, they must be cleaned.
There are cracks on the oil pump housing. In this case, the pump must be replaced.
Leaky connection between pump and tube.
There are cracks on the tube.
All chainsaws have an oil supply adjustment. Near the location of the adjusting screw on the body there is always a marking in the form of a chain link and a drop of oil. If you turn to the right, the oil supply will decrease. For the winter, the oil supply is increased, for the summer it is reduced. Strongly cannot be reduced, as the tire will burn.
The brake stops working for the following reasons:
Melting of the brake cover. Replace cover.
Video (click to play).
Chainsaws need regular cleaning from sawdust, dust, dirt, soot and replacement of spare parts. If you can do it yourself, you will save time and money.
