How To Unscrew Muffler With Stihl 361
DIY chainsaw repair principles

A chainsaw is an indispensable tool in the life of a home master. With it, you can saw off an old tree, build a bathhouse or just a gazebo for relaxation. Sometimes this tool also becomes unusable. To solve the problem, it is not necessary to contact expensive specialized services, you can repair the chainsaw yourself.
DIY repair
To carry out repairs at home, the availability of spare parts, tools and relevant skills. For example, for disassembling a chainsaw, a homemade repair kit that will take a very long time to come in handy.
General Disassembly Principles
Basically, all chainsaws have the same components, which are dismantled according to a certain scheme. If the assembly of the saw is Chinese, then there is nothing to worry about: most often they are made in the likeness of European models. How to disassemble a chainsaw:
- The clutch cover is removed.
- The starter cover is removed. To do this, you need to unscrew the screws and remove the transverse handle.
- To remove the handle, you need to remove the cover that closes the air filter.
- The gas hose is removed from the nozzle cover.
- The saw body is dismantled. It is necessary to unscrew the screws and remove the oil tank cap.
- Before removing the ignition module, it is necessary to analyze the clutch drum: it is necessary to rotate the crankshaft clockwise until the piston closes the gas outlet.
- Then you need to unscrew the clutch on the chainsaw and remove the coupling: you need to slightly hit it with a hammer.
- The screws are removed, the gas tank with the oil hose is dismantled.
Possible problems
The main problem that arises during the repair is the lack of necessary information on the repair. This is due to the fact that many foreign manufacturers believe that the saw should be disposed of after a certain period and production. Therefore, many masters have certain doubts, especially when repairing budget models.
But expensive professional models create certain difficulties:
Chainsaw Design
All chainsaws have the same design, regardless of whether the device, domestic (Ural, Cedar, Patriot 3816, Carver. Russian production with Chinese Partners) or foreign (Stihl, Husqvarna), for example, do-it-yourself repair of the Patriot 3816 chainsaw , like repairing a foreign device. The main components of the tool:
- Engine.
- Fuel tank.
- Starter.
- Handle.
- The tire with a chain.
The general principle of operation of the chainsaw is simple. the master jerks sharply at the cord that starts the engine, and he, in turn, is the saw blade. Sometimes, malfunctions occur in the operation of the device, in order to eliminate them, it is necessary to dismantle the saw. Problems that may arise with a chainsaw:
- It just won’t start.
- Starts up, but after a while it stops working.
- Does not work in cut.
- Power is falling.
The main problems that arise are problems with the engine (fuel supply, exhaust system, cylinder-piston system and ignition), or smaller problems (problems with the chain, lubrication, tire, oil seal). It is important to consider each problem in more detail..
If the chain simply broke, then it should be replaced with a new one. Problems with the solution of this problem should not arise. Repair of other parts of the saw can take up to several hours.
No matter how trite it may sound, if the chainsaw does not start, then you need to check the tank for gasoline. If there is fuel in the system, then a breather may have clogged, equalizing the pressure when the fuel was supplied.
The breather can be cleaned with a sharp awl or needle. Candles are turned out with a candle key and cleaned with sandpaper. You can also ventilate the combustion chamber.
After these procedures, the saw should start.
How to repair a chainsaw with your own hands
Today in any private courtyard you can meet a chainsaw. Modern chainsaws are very diverse. both by model and price. A very convenient and versatile tool, almost an indispensable assistant in the household. But sooner or later, all gasoline saws (European, Chinese) need repairs.
It is not always possible to contact the service center, so you have to do the repair yourself.
Various questions arise, for example, about what doesn’t work, what kind of repair kit is needed, and how to properly disassemble a chainsaw. Knowing the answers to these questions will greatly save your time and budget.
It will also allow to replenish the baggage of your knowledge and skills for more proper service of your assistant.
Chainsaw Design
All saws, be it Husqvarna, Stihl, Partner, Carver, have a common device principle. All of them consist of a housing in which are located: engine, starter, fuel and oil tank, tire with chain, rear and front handle.
In fact, this knowledge will not help in repairing the saw tool. Proper assembly and disassembly requires more in-depth knowledge. Even knowledge of the principle of operation of a chainsaw is not enough. Before you start disassembling, make sure that you can make repairs yourself. In some cases, special keys will be needed.
Main components and proper disassembly
Different models differ in the layout of units, mounts, etc. Therefore, the main points of dismantling certain nodes will be discussed below.
Before disassembling, it is necessary to thoroughly clean the outside of the saw from dirt, smudges of fuel and oil, chips and sawdust. Drain the remaining fuel and oil from the tanks. Detach saw blade from saw body. Next, consider the dismantling and repair of the main elements.
Starter Repair
A starter is needed to start the engine. Damage to this element is very rare, mainly due to intensive use. Breakage is manifested in the form of a banal breakage of the cord, not grasping the shaft with the flywheel, and jamming. For an experienced person, repairing the starter will not be any problem, but still consider a little more.
Essential elements:
- cord;
- pulley;
- flywheel;
- return spring;
- places of their landing.
Unscrew and remove the side cover. We inspect the contents, disassemble, clean from dust and dirt. We look at integrity and wear. If necessary, wind a new cord, replace worn elements. Lubricate movable mechanisms, assemble in the opposite direction. As practice shows, if this is not a break in the cord, it is better to change this unit immediately to a new one.
Carburetor repair
Perhaps one of the most difficult nodes. Assembly and disassembly require great care. It would be nice to have at hand a clear illustration of the carburetor device of the desired model.
We carefully disassemble, all the elements are best laid out on clean paper. After disassembling, thoroughly rinse every detail, purge the fuel channels. We assemble in the reverse order.
Having assembled the unit, it is necessary to set the factory settings of the carburetor and during operation to make adjustment to the end.
Ignition system
Despite the apparent simplicity of the assembly, repair requires fairly high skills. If you have not dealt with car ignition, then it is better to consult a specialist.
You can hardly independently correctly determine what exactly caused the malfunction. Therefore, it is best to limit yourself to visual inspection.
Check for thermal and mechanical damage. The ignition unit is usually replaced.
Clutch repair
Many people have a question about how to unscrew the clutch on a chainsaw. Let’s consider in order:
Piston group
This type of repair is caused by a drop in engine power. We disassemble the engine, remove the components and carefully lay them out. We look at the wear and cracks of the piston, valves, cylinder walls, bushings and connecting rod. Usually all components are replaced. Gland replacement is also required.
Above are the main capacious and complex types of chainsaw repair. But they do not pose much difficulty. You can fix almost everything, you only need your desire and zeal.
DIY chainsaw repair at home: why the chainsaw does not work, cleaning the carburetor, what to do if it wedges the chain, video
A chainsaw is an indispensable tool in the household. This is especially true of a country house. Such a tool is very easy to use and has a simple design. But, unfortunately, even all these advantages cannot guarantee the durability of the chainsaw.
Like another tool, a saw may fail sooner or later. But, do not be upset, as many problems can be eliminated at home. The main thing is to have certain knowledge and a set of tools.
Chainsaw device
Horizontal engine chainsaw
The chainsaw has a fairly simple device. If you know the basic elements of the tool, then if necessary, you can easily carry out repairs with your own hands. So, in a chainsaw you can distinguish the following main details:
- engine;
- clutch;
- oil pump;
- chain;
- brakes and catchers.
Depending on the brand, each chainsaw has its own structural features. So, if we talk about the engine, then it can be located both vertically and horizontally.
In professional tools, the engine is mostly vertical. As for models with a horizontal arrangement of the power unit, they have compact dimensions. This has become the main reason for their popularity and widespread use in everyday life.
Unfortunately, regardless of build quality, sooner or later chainsaws break. In frequent cases, repairs can be done with your own hands. But to do this, you must first determine the cause of the problem. Often a failure in work is associated with a malfunction of the power unit or other parts of the chainsaw.
So, if we talk about the power unit, then the problem can arise in the ignition, fuel supply and starter. Also, the problem may lie in the piston and even in the cylinder.
The malfunction of the power unit can be determined by the following symptoms:
- complete engine failure during operation;
- the unit starts up, but then stalls;
- the engine is not able to develop the necessary power;
- outages occur.
Before proceeding with any actions, it is necessary to carefully analyze the situation.
Ignition system and its problems
Elements of the ignition system
Often engine problems are associated with ignition. That is why you need to start the inspection with this system. First you need to get a candle and carefully inspect it. Here it is necessary to carefully remove the wire and unscrew the candle. Do this with a special key.
If the spark plug is wet, then this is a clear sign of an excess of fuel. This is mainly due to improper operation of the ignition system or carburetor.
As for the candle, it must be thoroughly wiped dry. It is also worth draining the cylinder. To do this, shut off the fuel supply and start the starter several times. Using these actions, you can remove excess fuel.
Next, the candle is put in place and the engine starts.
Important: Before installing the candle, you need to make sure that there are no dirt and moisture on it. This will directly affect its performance.
If there is black soot on the candle, this indicates the use of bad oil or the combination of oil with gasoline in the wrong ratio. In some cases, carburetor adjustment may be necessary. Here, the candle must be cleaned of carbon deposits and installed in a nest.
If the tool still does not start, then it is worth checking for the presence of a spark: put on a candle a high-voltage cable and lean it against the cylinder. After that, you need to pull the starter several times. As a result, a spark should occur between the electrode and the cylinder.
If the above actions did not give a result, then it is worthwhile to replace the spark plug and check the tool in operation. If a spark does not occur, then the problem is probably hidden in the high voltage wire.
Fuel Issues
When the inspection has failed, you can begin to diagnose the fuel supply system. The cause of a system problem may be:
- dirty fuel filter;
- stopping the hole in the tank cap;
- supply of a small amount of fuel.
Here, first of all, it is necessary to disconnect the fuel hose and check whether fuel flows out of it. Provided that the fuel flows in a normal stream, then everything is fine.
If the jet is weak or completely absent, then you need to clean the hole in the lid with a needle. To clean the filter, drain the fuel. Using a hook, the filter along with the suction hose is pulled through the filler opening.
The filter must be thoroughly cleaned or replaced with a new Chinese counterpart, which has a low cost. The fuel filter should be cleaned every 3 months. With frequent use of the tool, the frequency of cleaning increases.
An important element of the system is the air filter. It is recommended to periodically clean it. The filter must be removed very carefully, otherwise dirt may get into the carburetor.
Malfunctions of the carburetor and muffler
If the previous steps did not solve the problem, then it is worth going to the carburetor check. If necessary, it will be adjusted. If you have not encountered such a problem before and have not performed the adjustment at home, then it is better to use the services of a specialist.
Otherwise, a mistake will lead to more serious problems. A carburetor is a complex device that consists of small parts. Careless disassembly may cause parts to be lost.
With frequent use of the tool, problems may arise with its muffler. In the process, carbon deposits form on the walls of the pipe, which further impedes the exit of exhaust gases.
To eliminate this problem, it is necessary to remove the muffler and rinse it thoroughly. To do this, use special detergents. Before installing the silencer in place, it must be thoroughly dried.
It’s important to know: When cleaning a silencer, it should be borne in mind that carcinogens are contained in soot. When dry cleaned, they can get into the respiratory tract, which will negatively affect health.
Lubrication and chain brake problems
The manual that came with the chainsaw indicates the need for control of the chain lubrication system. A common cause of the problem is clogging of the channels responsible for lubricating the lubricant. If the oil leak is insignificant, then the tool can be used further for its intended purpose. But, if you notice a significant leak, then it must be immediately eliminated.
First you need to check the tightness of the connection of the tubes with the fittings. If necessary, replace the tubes or seal the connection using special materials.
It is also necessary to check the oil pump. If cracks are visible on its body, then it needs to be replaced.
In cases where the chain brake does not work, a thorough inspection of the brake band is necessary. In the process, it may become contaminated with grease or sawdust.
Replacing consumables
In addition to the above problems, other malfunctions can occur with a chainsaw. This mainly applies to consumables that have their own life. So, in the process of work, the outcome of the tire, the drive sprocket, and other details may occur.
To prevent the occurrence of more complex problems, it is necessary to timely change such parts.
With such knowledge, you can repair such chainsaws as Friendship 4, Stihl 180, Husqvarna, Urals, with your own hands. This will significantly reduce repair costs.
Below, we suggest you watch a video on how to fix a chainsaw at home with your own hands:
DIY chainsaw repair according to all the rules Video
Video about the device of a chainsaw
Absolutely all chainsaws are similar in structure, regardless of where they are produced. Be it European "ECHO" or domestic "Cedar".
In the chainsaw body you can find the main elements. a fuel tank and an engine. On the outside of the case are a starter, a handle, a saw part with a chain. A chainsaw starts after twitching the cable, which first starts the engine, and then the blade.
Most often, the following occurs with a chainsaw:
Repair from A to Z
First of all, you have to make out the saw. In 90% of cases, the tool malfunctions due to interruptions in the engine. Otherwise, the breakdown is associated with a violation of the fuel supply system, misalignment of the carburetor screws, the exhaust system or the broken cylinder-piston part that has become unusable.
Less often, other systems and components of the tool fail. the clutch, brakes, lubrication system. Let’s look at how to repair a chainsaw without damaging the tool.
Do-it-yourself chainsaw repair should begin with the identification of faulty parts. First of all, inspect the spark plug by first disconnecting the wire. The appearance of the candle says a lot:
- If it is dry, the incendiary mixture does not enter the cylinder. So the problem is not in the candle.
- If it is heavily contaminated with fuel, the carburetor is damaged. You need to carefully wipe the candle and shut off the fuel supply temporarily. Then turn on the starter and remove any remaining fuel. After the operations done, ventilate the combustion chamber and put the candle in place.
- If the candle is covered with a black layer of soot. most likely, you used low-quality oil or incorrectly adjusted the carburetor. Rinse the candle thoroughly, remove the remaining carbon deposits and wipe the electrodes with a sandpaper. Then put the candle in place and try to re-start the chainsaw.
Tip: After you inspect the candle, make sure that the gap between the electrodes is normal. In the ideal case, it should be 0.5-0.65 mm. It is advisable to replace the worn gasket.
It will not be superfluous to check for a spark in a chainsaw. To do this, put on the spark plug on the spark plug and connect the spark plug nut to the cylinder. Then start the starter and follow the spark. If it appears, then the candle is faulty, otherwise the problem is in the wire.
After diagnosing the spark plug, inspect the fuel supply system. It may not fall into the cylinder for several reasons:
Another common failure in a chainsaw is a faulty carburetor. How to repair the chainsaw carburetor with your own hands?
Remember that the carburettor can only be adjusted with screws L and H. If you want to increase the speed. turn the screws clockwise, lower. vice versa. On this, the carburetor adjustment is considered complete.
Video: How To Unscrew Muffler With Stihl 361
Silencer Cleaning and Maintenance
Chainsaw Maintenance Video
After all operations, it does not hurt to repair and clean the muffler. After all, it often happens that at high speeds the chainsaw begins to stall. This is due to the fact that the spark arrester is clogged with combustion products. To clean the muffler from soot should be done only with detergents; dry cleaning is hazardous to health, since harmful substances are present in soot.
After removing the muffler, it is advisable to close the exhaust outlet with a clean cloth. Remember that in order to avoid clogging of the muffler, you should carefully monitor the fuel mixture.
If your engine does not work or you notice a significant loss of power, then this is most likely due to the low pressure in the cylinder. In 80% of cases this occurs due to wear of the bearing, piston, cylinder. It is advisable to place the compressor in the candle hole for a complete analysis of the cylinder-piston system of the instrument.
Specialists are also advised to monitor the chain lubrication system. The main malfunctions in the system are as follows:
- Oil leakage. This is due to the fact that the tubes are not hermetically connected to the fittings. It is advisable to replace or seal up such tubes.
- Not enough oil. In this case, most likely, the channels for supplying lubricant are clogged.
- And the last malfunction is cracks in the oil pump housing. Here, unfortunately, can not do without repair.
The last thing you should repair and adjust is the chain brake. Most often, it does not work due to the fact that it is clogged with some kind of sawdust or oil. It is necessary to clean all parts of the brake from dirt and sawdust. There are times that the cause of the breakdown lies in a worn tape. In this case, repairing chainsaws, you can not do without replacement.
Due to the fact that the repair and maintenance of the chainsaw must be done as often as possible, you should always have the following spare parts at hand:
- drive sprocket. it jumps off the shaft;
- chain. breaks at the wrong time
These parts are most susceptible to wear, as they work under abrasive conditions. DIY chainsaw repair will allow you to get rid of all the malfunctions for little money.
Wizard Tips
A chainsaw with all the desire can not be attributed to complex devices. over, the simplicity of the design is its hallmark. Nevertheless, repairing a chainsaw can take a lot of time. The difficulty is not in the repair itself, but in the accurate diagnosis of the malfunction.
One and the same sign of inoperability can be caused by many reasons. Therefore, before you immediately begin to disassemble the carburetor or engine, you need to think carefully and analyze the symptoms of the malfunction. No chainsaw repair manual can replace simple logic.
Chainsaw Repair
All malfunctions of chainsaws can be divided into two main groups: malfunctions of the engine with all its components and systems (ignition, fuel supply system, cylinder-piston group, exhaust system) and malfunctions of other components (chain brake, lubrication system, clutch, tire, etc. ).
Violations in the operation of chainsaw engines occur quite often, it is their detection and correction that takes the most time from users. Basically, they come down to the following manifestations:
- The engine will not start;
- Starts up, but stalls;
- unstable;
- does not develop power, i.e. normally works at idle, but stalls under load.
When repairing a chainsaw with your own hands, you need to use the exclusion method. to check alternately all possible causes of the malfunction, starting with those that take less time to check and eliminate (see here for the design and operation of a two-stroke engine).
Ignition system. Almost all types of engine malfunctions listed above can be caused by ignition system malfunctions.
Therefore, when they occur, it makes sense to start troubleshooting with a candle. This is all the more justified because the state of the latter can provide useful information about the operation of the fuel system.
So, if a problem occurs, you need to turn out the candle and inspect it.
Chainsaw ignition system:
1. flywheel with built-in magnets, 2. ignition module, 3. spark plug, 4. high voltage wire.
The wire is disconnected, and the candle is twisted with a special key.
Unscrewing the spark plug.
If the candle is dry, it means that the problem is most likely not in the ignition system, but in the fuel mixture not entering the cylinder. You can wrap the candle back and take up the fuel system. If the candle is heavily sprayed with the fuel mixture, then there is an excess of it.
This may occur due to misregistration of the carburetor or violation of the rules for starting. The candle is wiped and dried, the cylinder is drained, cutting off the fuel supply and working as a starter to ventilate the combustion chamber and remove excess fuel.
Then set the candle in place and repeat the launch.
The presence of a large amount of black soot also indicates a malfunction in the fuel system.
Candle with black soot.
The ratio between oil and gasoline in the mixture may be violated, the carburetor is not adjusted, or poor-quality oil is used. The candle is washed in gasoline, cleaned with a needle or an awl of carbon deposits, clean the electrodes with a fine sandpaper and put in place.
In all these cases, it is not superfluous to check the gap between the electrodes of the candle. Depending on its brand, it should be in the range of 0.5-0.65 mm. It is necessary to check the sealing gasket of the candle. If it is worn or damaged, the tightness of the combustion chamber may not be ensured, which leads to a decrease in compression in the cylinder and problems in the engine.
Even if in the case of checking the spark plug there is good reason to believe that the fault is in the fuel system, you need to check the spark plug for a spark. At least in order to be sure that everything is in order with this. For this:
- put on the spark plug cable;
- using pliers with insulated handles, apply thread or nut to the cylinder;
- pull the starter handle and see if there is a spark or not.
If there is no spark, you just need to replace the candle. If the new candle does not have a spark, it is necessary to check the condition of the high-voltage wire for an open and contact with the candle.
The reason for the absence of a spark can also be a faulty ignition module or a violation of the gap between it and the flywheel magnetic circuit. It should be 0.2 mm.
Violation of the gap becomes especially likely if before that the saw was disassembled with the flywheel and the ignition module removed. The clearance is set with a gasket 0 thick.
2 mm placed between the flywheel boss and the ignition module. Defective ignition module must be replaced.
Having checked the ignition system in this way and not having detected a malfunction, we can proceed to the fuel mixture supply system.
Fuel supply system. If inspection of the spark plugs found that fuel does not enter the cylinder, you need to consider all the possible reasons for this. It could be:
- non-receipt of fuel from the tank due to a clogged hole in its cap (breather), while a vacuum is created in the tank that prevents fuel from flowing out;
- contamination of the fuel filter installed in the tank;
- not receipt or insufficient supply of fuel mixture from the carburetor to the cylinder.
To diagnose the first two reasons, it is enough to disconnect the fuel hose from the carburetor and see if fuel flows out of it or not. If it flows fully, the breather and filter can not be checked, if it does not or weakly flows, we can assume that the cause of the malfunction is found.
The breather is cleaned with a needle. The fuel filter is removed through the filler hole of the empty fuel tank with a wire hook, together with a suction hose, from which the filter is disconnected and cleaned or replaced with a new one.
Chainsaw manufacturers recommend changing the fuel filter every 3 months.
Fuel filter.
An insufficient supply of the fuel mixture from the carburetor to the cylinder or a violation of the correct ratio between the fuel and air mixed in the carburetor can occur for several reasons: due to clogging of the air filter, unregulated carburetor, clogging of its channels or mesh filter.
As a rule, repairing chainsaws is not complete without cleaning the air filter, since it gets dirty quite quickly.
When this happens, air intake to the carburetor decreases, the fuel mixture at the outlet of it turns out to be too enriched, which disrupts the normal operation of the engine.
Carefully remove the dirty filter for cleaning so that dirt does not get into the carburetor. The filter should be cleaned or washed in water with some detergent, dried and installed again.
Air purification system:
1. the cover closing the fine filter, 2. the fine filter, 3. the cover closing the coarse filter, 4. coarse filter (it may not be).
Carburetor misregistration is eliminated by its adjustment. Usually this is done with three screws. maximum and minimum speed and idle screw.
Adjustment must be carried out in strict accordance with the instructions, non-observance of which can lead to engine damage.
Some manufacturers of saws leave only one adjustment screw (idle speed). to exclude unwanted interference of inexperienced users in the operation of the carburetor.
If the carburetor adjustment did not help, you need to clean its channels and filter mesh, and at the same time check the integrity of the membrane.
A carburetor is one of the most complex chainsaw devices, so you need to start disassembling and cleaning it with a full understanding of the responsibility of this operation.
It consists of many small parts that have the peculiarity of quietly popping out of their seats and irretrievably lost, so that, having disassembled this capricious device, you can not assemble it.
Chainsaw carburetor.
Top arrow. fuel hose lower. air damper drive.
Chainsaw carburetor.
Arrow. A cable of the lever of a drive of a butterfly valve.
Chainsaw carburetor.
Arrow. fuel hose.
Dismantled chainsaw carburetor.
Below is a diagram of another carburetor chainsaw.
Chainsaw carburetor circuit.
If there is no experience and self-confidence, it is better to entrust the repair of a chainsaw carburetor to a service center specialist. Sometimes for high-quality cleaning of the carburetor it is necessary to apply ultrasonic cleaning.
Muffler. Often the cause of engine malfunction, especially in the case when the engine is operating normally at low revs and stalls under load, becomes clogging of the silencer’s spark arrester, which prevents normal exhaust, from the combustion products.
Repair in this case consists in removing the muffler, disassembling (if it is collapsible) and wet cleaning it from soot using detergents. The non-separable muffler is dried with a hairdryer after washing. Remember that soot contains substances that are carcinogens, and dry cleaning, which may result in inhalation, is unacceptable.
When removing the muffler, the engine outlet is plugged with a clean rag.
Chainsaw silencer.
One of the reasons that the silencer may become clogged is the use of a fuel mixture with excess oil (the amount of oil is more than the manufacturer recommends), and the use of oil that is not suitable for two-stroke engines or low-quality oil.
Cylinder-piston group. Malfunctions of the cylinder-piston group are the most serious.
This is the deterioration of the cylinder and piston, scratches and seizures on their surface, wear or sinking in the grooves of the piston rings, wear of the crankshaft bearings.
Most of these malfunctions lead to a drop in pressure in the cylinder and, as a consequence, to the inability to start the engine, or its inability to give full power. There are several ways to assess the status of a cylinder-piston group (CPG).
Piston and crank mechanism.
You can remove the muffler and look through the opened window, in which a part of the side surface of the cylinder is visible. Despite the limitations of the review, a general idea of the state of the CPG in this way can still be obtained.
It is useful to measure the compression in the engine, which is quite informative regarding the condition of the parts of the CPG. The operation is carried out using a compressor installed in the candle hole.
Chainsaw engine compression measurement.
The crankshaft is rotated using an electric motor (drill) with a flexible shaft or manually by a starter, while controlling the pressure on the pressure gauge. The last for a workable chainsaw should be at least 8-9 atm (0.8-0.9 MPa). With its decrease, engine power also drops. At a pressure of 5 atm, the engine may perhaps work, but only at idle.
It is possible to accurately assess the condition of the CPG only by completely disassembling the engine. by disconnecting the crankcase from the cylinder and removing the piston. If the latter has scuffs, chips or deep scratches, it must be changed.
In relation to the cylinder, when developing or damaging the surface, it is possible to squander it under the repair size. The cause of low compression may be wear and coking of the piston ring.
The serviceable ring should be clean of carbon deposits, sit in the piston groove freely and firmly pressed against the inner surface of the cylinder.
Chain lubrication system
A rare guide for repairing a chainsaw goes without mentioning the faults in the chain lubrication system, which are quite common. They usually occur in non-delivery or insufficient supply of lubricant to the chain and in oil leaks. If the chain is dry, first of all it is necessary to inspect and clean the channels through which oil is supplied to the tire. Their clogging is not uncommon.
Chainsaw oil pump.
Oil pump adjustment. 1. adjustment screw.
With a significant (small is considered normal) oil leakage, it is necessary to check the tightness of the connection of the tubes to the pump fittings. They may fall or crack.
Violation of the tightness of the oil pipe, in addition to sagging, can lead to insufficient lubrication of the chain. The pump begins to suck in air, which affects its performance.
The leak is eliminated by replacing the tubes or sealing them with sealant.
The most serious damage to the lubrication system are cracks in the oil pump housing. In this case, it will have to be replaced.
Failure of the chain brake can occur due to contamination of the underwing and brake band with sawdust or grease. The wear of the tape also leads to this. In the first case, it is necessary to clean the axillary space, in the second. replace the brake band.
Chainsaw brake device.
Replacing Wear Parts
Some parts of the chainsaw, subject to natural wear and tear, must be replaced after a certain period of operation. Their failure is not considered a malfunction. Wear parts include a chain, a tire, a drive sprocket, anti-vibration system elements and some others.
If you do not replace the wearing parts in time, their excessive wear will adversely affect the other parts of the chainsaw. In particular, if you do not change the tire and the drive sprocket in time, increased vibration will adversely affect the crankshaft bearings.
The maximum depth of the tooth teeth should be 0.5 mm. In practice, sprockets are often operated up to a wear depth of 1 mm or more, without suspecting that this leads to an increased load on the crankshaft bearings and their accelerated failure.
When 3-4 chains are worn, it is necessary to change the tire itself, by this time its wear reaches its limit values.
The chainsaw tire wears out especially in the area that is cut most often, usually the underside of the guide bar. For uniform wear, each time the chain is replaced, the tire must be turned 180 ° relative to the horizontal axis.
When installing a new chain, a new drive sprocket should be installed. Since under normal load the service life of the drive sprocket is twice as long as the service life of the chain, it is advisable to use one sprocket for alternating operation of two chains.
Thanks to this, the sprocket and chains wear out almost simultaneously. If a new chain is placed on a worn sprocket, then the leading chain links wear out much faster.
For cost-effective operation of the chainsaw, always spend together: one guide bar, two chain sprockets, four saw chains.
By the way Chinese chainsaw repair not needed, just throw it away.
DIY Chinese chainsaw repair video
The main condition for a successful repair is the correct diagnosis. Therefore, to determine why the chainsaw is out of order 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 nodes (ignition, filtration, lubrication, etc.), that is, the tool as a whole.
In order to simplify the diagnosis of faults, they are usually distinguished into two main categories:
- engine malfunctions;
- malfunctions of other nodes of the chainsaw.
Most often, failures occur in engine systems. however, the remaining parts of the tool, due to heavy use or improper maintenance, may fail at any time. How to determine exactly where the breakdown occurred? This will help us with simple logic.
If the problem is in the engine, it will:
- do not start;
- to stall;
- unstable to work;
- overheat;
- smoke;
- develop insufficient power.
As for all other malfunctions, as a rule they manifest themselves with a normally working motor.
Starting the engine: checking the candles
If the chainsaw does not start, the first thing to do is check for 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;
- fuel splashed candle
It is the result of an overabundance of the fuel mixture, which lies either in violation of the engine starting algorithm or in the incorrect carburetor adjustment;
this is a signal about the presence of poor-quality oil in the engine lubrication system, incorrect carburetor settings, or an incorrectly prepared fuel mixture.
If the spark plug is splashed with fuel, it must be wiped thoroughly after removal. The fuel supply system should also be cleaned. To do this, it overlaps, after which the starter turns on. A candle covered with soot must be carefully cleaned with an awl and emery.
When checking candles, attention should be paid to the distance between the electrodes (normal clearance 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 starting the starter.
If discharge does not occur, replace the spark plug. In the event that a spark does not appear with a new candle, it means that the problem is with the connection to the high-voltage wire or in it.
DIY chainsaw repair: fuel supply system
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 if it is completely worn out.
As a preventive measure, it is recommended to replace the fuel filter at least 1 time in 3 months.
This is nothing but a hole in the fuel tank cap that is cleaned with an awl.
The fuel mixture is not supplied or is not supplied in sufficient 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 in place);
- carburetor settings are lost (this node must be re-adjusted);
- the integrity of the carburetor membrane is violated (must be replaced);
- clogged carburetor channels (it is necessary to disassemble and clean all parts and assemblies).
Silencer Troubleshooting
If at low speeds the chainsaw motor works fine, but at high speeds it starts to stall and smoke, the problem may be hidden in the muffler.
To verify the quality of its work, you must perform:
- dismantling (with mandatory closing of the outlet);
- disassembly (if the silencer is collapsible);
- cleaning of carbon deposits using special detergents or by dry method;
- drying (using a hairdryer);
- Reassembly and assembly.
Dry cleaning without respiratory protection is not recommended. The carcinogens present in the tan 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 operation of the chainsaw, you should carefully monitor the composition of the fuel mixture and the quality of its components.
Repair of a cylinder-piston group (CPG)
If the engine of the chainsaw does not start or cannot develop normal power, it is likely that the pressure in the engine cylinder does not appear sufficient to burn the fuel mixture.
The reason for this may be the wear of the elements of the cylinder-piston group. the piston, rings, bearings, etc.
In order to assess the condition of this unit, it should be visually inspected by first removing the muffler.
For a more complete diagnosis, a compressometer is placed in the spark plug hole of the two-stroke chainsaw engine. With its help, the compression in the engine is measured. Based on the results of the check, it is possible to judge the state of the CPG, however, accurate facts can be obtained only with a complete disassembly of the assembly.
If chips or scratches are present on the piston, it is obvious that they 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 of soot.
Check carburetor and signs of the need to adjust it
A correctly working carburetor guarantees maximum efficiency of the chainsaw, that is, it is possible to develop full power at 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 tuning already in use.
The fact that such a setup will have to be performed by the owner of the chainsaw is indicated by:
Adjustment of the carburetor of the chainsaw is carried out in strict accordance with the manufacturer’s instructions with the help of three special screws that are responsible for the maximum ("M") and minimum ("L") revolutions, as well as the engine idle speed ("T"). In order to eliminate unwanted interference by an inexperienced user in the operation of the carburetor, some manufacturers install only one idle screw.
Calibration algorithm and safety precautions for troubleshooting a chainsaw carburetor
Carburetor adjustment is carried out in two stages:
For basic adjustment, screw the H and L screws all the way and turn them back 1.5 turns. Finishing adjustment requires that the engine be warmed up for 5-10 minutes at low speeds.
Finishing calibration is performed by unscrewing the idle screw until the minimum engine speed is reached (its operation must be stable and the chain stationary). If the engine stops at idle, the screw must be returned back, and in the event that the saw chain is nevertheless set in motion, it should be continued to turn it counterclockwise.
Calibration verification is performed by the test:
If the owner of the chainsaw is not familiar with the carburetor device and does not have the necessary tools for calibrating it, you should contact a specialist. A carburetor is a very complex unit, so any improper action can lead to irreversible consequences, for example, complete engine failure.
Other chainsaw malfunctions
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 parts of the chainsaw. The most common problems are:
- starter failure;
- improper operation of the lubrication system;
- incorrect operation of the chain brake;
- chain wear, etc.
If the cause of the failure of the tool is not visible to the naked eye, as in the case of the engine, it is necessary to carry out a thorough diagnosis of malfunctions and eliminate them in accordance with the manufacturer’s recommendations and safety regulations.
DIY chainsaw repair, video
The 18 most useful and interesting chainsaw repair videos
No wonder they say that everything is not forever. The chainsaw starter cord broke. the workshop is far away, and there are no funds for repairs. What to do? You can quickly and easily do it yourself.
Audit or preparatory work with a chainsaw
Revision, preventive and preparatory work with a chainsaw are clearly demonstrated in this video. Any tool requires attention. So that in the future he will serve you clearly and without fail, you should do this work in a timely manner.
Quality Supplies for Chainsaws
The necessary supplies for chainsaws presented in this video. We’ll also talk about oil filling, changing chainsaws and replacing tires.
We repair independently the chainsaw ignition toggle switch
Often knocks out the ignition switch? A little trick to get around this problem.
Replacing the drive sprocket in the chainsaw
Need to replace the drive sprocket on a chainsaw? We look and learn how to do it on Husqvarna / Husqvarna chainsaws models 142, 365; STIHL / Stihl MS 361 and Chinese GooD LuCK.
Assembly instructions for Makita chainsaws (Makita)
A good example of how to assemble a chainsaw correctly, what tools and sequence of assembly order are needed for this.
Chainsaw Lubrication System. Oil Pumps
Video about the lubrication system of chainsaws Husqvarna (Husqvarna), Pertner (Partner), Chinese Kanakov, namely about oil pumps. Their design, disassembly, assembly, causes of failure and their elimination. all this can be found in the video.
Repair of frequent breakdowns of the STIHL chainsaw (Stihl)
Repair of the air damper and malfunction of the acceleration of the revolutions of the STIHL chainsaw (Stihl). You can complete these steps yourself by watching this video.
Carburetor repair chainsaw Stihl МС 250
How is all this done? The cause of the breakdown is that the saw does not start well, does not gain the required speed and stalls. The wizard will show you step by step how to fix these problems.
Repair oil supply chainsaw Stihl MC 250
The jack of all trades intelligibly and with humor will tell you how to deal with a malfunction in the Stihl chainsaw feed oil.
Chainsaw repair Stihl 180
The reason for the breakdown of your Stihl 180 chainsaw is that it cannot be adjusted either gas or idle and starts poorly. It can be fixed. The specialist will intelligibly present to your attention how the problem is solved in the home workshop.
Husqvarna 236 chainsaw repair
We examine the chainsaw, we find the cause of the breakdown. The carburetor clogged and the gas supply failed. The most common chainsaw problem of this model. We repair together and fix the breakdown.
Dismantling the Husqvarna 440 x-torqe chainsaw
The dismantling of the husqvarna 440 x-torqe chainsaw takes place to the smallest detail. Now you can replace non-working parts with new parts. Clean them from dirt and dust and collect the chainsaw yourself. The tool is ready to go.
Piston repair on a Chinese chainsaw
The chainsaw worked for several hours and broke. What to do? Demonstration of replacing a piston group with a Sterm chainsaw (made in China). The piston diameter is 43 mm and 45 mm.
Chainsaw device
The ZD model of a chainsaw from a disassembled state is assembled practically by screws.
Replacing and tensioning the chainsaw chains
If a chain has fallen off on a gasoline saw, what should I do? How to return the chainsaw to working condition? Just a couple of minutes and you can do it yourself by watching the video.
How to revive a Shtil MS 250 chainsaw carburetor
The chainsaw worked for two years and that’s not the problem. the carburetor broke. Is the problem familiar? You will learn how to solve it yourself by watching the video.
Husqvarna & Partner Clutch Repair
Clutch disassembled presented to your attention. What does the clutch consist of, as well as what frequent breakdowns are found in these parts? If interested, watch the video review.
How to do DIY chainsaw repairs
The choice of gasoline saws is determined by several criteria. One of them is a chain saw chain step. This parameter determines the capabilities of the equipment, the speed of cutting materials and should correspond to engine power, only in this case it will be possible to extend the life of the tool and reduce the specific fuel consumption.
With prolonged use of the chainsaw, its individual components may fail. Most often, it is necessary to repair the oil pump of a chainsaw. This is due to the fact that during the sawing process a large amount of chips is formed, which can fall into the working mechanism.