What a chain saw disassembled looks like

What you can make with a chain saw by yourselves

Dismantling of a chainsaw is an important process that allows to carry out its complete cleaning from dust and dirt, repair its individual assemblies and mechanisms, reactivate this power tool after winter, etc.д.

Complete disassembly and reassembly will require your knowledge, skills, and most importantly, attention to detail, because after you have disassembled the chainsaw, it must be assembled so that there are no extra screws and bolts.

And if you have no experience in disassembling this power tool, we strongly recommend that you first watch a few instructional videos on the subject. Fortunately now on YouTube there are enough such videos devoted to all popular chainsaw brands.

You also need disassembly in order to install new parts for chain saws instead of the failed one, which you can also buy in our online store.

Chainsaw malfunctions and how to repair the bar with your own hands

A chainsaw is a necessary thing in the household and garden, helping to quickly and accurately perform various work with wood. Like any electrical device, it occasionally malfunctions and needs diagnosis. The result of the latter often leads to the conclusion that it is necessary to repair the chain saw tire. the mechanism that experiences most of the load when working.

Disassembling a Chinese chainsaw

Detailed photo instruction on how to fully and consistently disassemble all parts of the mechanism. On the example of Chinese chainsaw, the principle of interaction of all structural elements is shown. Disassembly is performed on a clean drive without tire, chain, gasoline and oil.

To facilitate the manipulation of the object and easy access to the parts, first remove the handle, unscrewing the tire cover in advance.

With some room for maneuvering we can move on to the main components. Remove the top cover, the air filter and the spark plug.

Undo the mounting screws and remove the cylinder head.

Remove the carburetor, for which we disconnect the lever of the air damper, unscrew the 2 fixing screws and remove the air filter base. Disconnect throttle trigger and exhaust pipes.

Remove throttle lever that does not interfere with further disassembly. To do this we remove the upper cover of the handle, disconnect the rod from the trigger and take it out through the hole.

Remove the starter cover by loosening the 4 screws.

Proceed to disconnect the housing from the crankcase by removing the chain catcher and shock absorbers.

Disassembly of the engine begins with the removal of the carburetor elbow ring, gasket and insulator. For convenience, it is better to use narrow pliers.

Unscrew the fastening nuts/screws and remove the muffler. Remove the gasket and pins.

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Now, the removal of the engine cylinder is reduced to a simple unscrewing of 4 screws. You need a screwdriver or a bit with a long rod.

To detach the piston from the crankshaft, remove the circlip and lift out the shaft.

The ignition module is fixed with a couple of screws and can be removed with a few rotations of the screwdriver.

The clutch is unscrewed counterclockwise and rotates together with the crankshaft, which must be secured by placing the axis in the handle of the pliers. You can use a wrench from an angle grinder, or a hammer with a chisel, but it is better to take a special puller.

Chainsaw repair: how to identify and troubleshoot your chainsaw with your own hands

Nowadays almost every villager or countryman has a chainsaw. They are in high demand, because they are quite easy to work with.

Even if it breaks, it can be repaired with your own hands, although it can be very time-consuming.

Household or semi-professional (farming) saws are used by consumers in their households, which are designed for small jobs.

Design of chainsaw

Basically, all chainsaws are equipped with a two-stroke carburetor engine with one cylinder and air cooling. Stability of operation depends on the carburetor, which prepares the air-fuel mixture. The air entering the engine must be free of dust and other impurities that clog it, otherwise the piston group will wear out rather quickly.

The air filter in your chain saw needs to be cleaned regularly to prevent this. To make it clog less often, it has an air precleaner.

The engine is started by a starter motor (a rope with a crank wrapped around a pulley). Modern, even low-powered saws are equipped with mechanisms that facilitate starting. These include:

  • primer. reducing the number of empty revolutions pump pre-pumping fuel;
  • Spring starter, which allows you to slowly pull the cable, the engine is not cranked, but only a special spring, at some point it overpowers compression and sharply cranks the crankshaft;
  • the decompression valve connects the cylinder to the atmosphere, reducing the pressure in it, which allows you to start the engine without much effort, the valve closes after starting under the pressure of the exhaust gases.
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the chainsaw can vibrate a lot when working, that’s why it is equipped with an anti-vibration system. The saw handles are connected to the engine by means of a damper (a rubber gasket or a steel spring).

The sawing part of the chain consists of a cutting chain located on the edges of the bar, a sprocket and a chain wheel.

Troubleshooting the chainsaw

Unfortunately, chainsaws, just like other units, can fail. With at least a little understanding of how the saw works, most malfunctions can be corrected with your own hands. The complexity of the repair is not so much in the work itself, as in the correct determination of the cause of failure.

For example, if the saw does not start, there may be several reasons, so you should not immediately start disassembling it. First analyze the causes of failure, which are divided into 2 groups:

  • Malfunctions in the engine, ignition system, fuel supply, or exhaust system. This also includes malfunctions of the cylinder. piston group.
  • Malfunctions in the lubrication system assembly, chain brake, clutch, or tire, as well as a number of other malfunctions.

Indicators of engine malfunction

Engine malfunctions can be judged by the following problems that occur:

  • It is impossible to start the engine;
  • The engine starts but then immediately stops;
  • the engine works unsteadily;
  • At idle rpm works normally, but at load loses power or stalls.

All of these faults may indicate ignition system malfunction.

Check ignition system

Inspection of the system should begin with an inspection of the spark plug. Dry, it indicates that the fuel mixture did not get into the cylinder and therefore the ignition is not involved. If the spark plug is too full of fuel mixture, the saw was not started correctly or the carburetor is not properly adjusted.

Wipe the spark plug thoroughly, then cut off the fuel supply, remove fuel residue, ventilate the chamber and start the starter. Replace the spark plug and restart the engine.

Black carbon deposits indicate that you have used bad oil or that the fuel mixture has a bad oil to gasoline ratio. The problem could be a faulty carburetor.

The spark plug should be washed and soot removed with a sharp needle or awl, the electrodes should be finely ground and the spark plug screwed back in.

When checking the spark plug, pay attention to the gap between the electrodes. The operating limits are 0.5 to 0.65 mm. If the spark plug has a worn or damaged gasket, it may also cause problems with starting the engine. The spark plug should also be checked for spark.

to do this, the spark plug is connected to the cable, then clamped with pliers with insulated handles and the thread or nut of the plug is put on the cylinder. by pulling the starter rope, check if there is an spark. If there is no spark, the spark plug is simply replaced.

If a new spark plug does not give spark, then the problem is in the high-voltage wire.

Troubleshooting in the fuel system

Fuel cannot enter the cylinder for several reasons:

chain, disassembled
  • The fuel filter is soiled. To remedy the problem, remove the fuel hose and see how the fuel will leak. The fuel filter should be cleaned if trickle is poor. Pull it out through the fuel filler hole, clean the filter, and if heavily contaminated, replace it with a new one.
  • The breather. a small hole in the tank lid. is clogged. You need to remove the hose and clean the blockage with the needle.
  • Fuel is out or not enough. Cause. clogged air filter. Air is not getting to the carburetor in the right volume, the fuel mixture is too enriched, which disturbs normal engine operation. The filter should be carefully removed, rinsed, dried and replaced.
  • The carburetor is not properly adjusted. Since it is one of the main units of the engine, it is better to entrust the adjustment of the carburetor to a specialist. Self-adjustment can finally put the engine out of operation.

Disassembly of clutch and oil pump drive

Before disassembling the clutch, the drive sprocket must be disassembled. To do this, carefully remove the lock washer from the grooves on the shaft and remove the sprocket and needle bearing.

High head 19, unscrew the clutch. The thread stays on it, so it unscrews to the bar and not behind the STIHL 180.

After unscrewing and removing the clutch you must immediately remove the deflector plate and pump the oil out of the pump, this is easy to do as they are fitted on the shaft without fasteners.

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What is required for a do-it-yourself repair

To use any machine properly and for a long time you need to understand the inner workings of the parts and mechanisms. And also to know the rules of operation.

Begin repairs without getting acquainted with the technical side of the case is not recommended, as it can only aggravate the problems and lead, in the future, to more problems.

If the reader is familiar with the device of the chainsaw, he can safely skip this section and go directly to the next, which describes the main types of breakdowns and ways to fix them.

For those, who hold a non-functioning chainsaw in their hands for the first time, here is a short synopsis of chainsaw construction.

The engine that drives the cutting chain is an air-cooled, single-cylinder, two-stroke internal combustion gasoline engine. The motor is controlled by adjusting the quantity and quality of gasoline in the combustion chamber. Controls are throttle valve on carburetor linked to button on handle.

Controls on chain saw

Its operation is ensured by a fuel supply system consisting of:

    Gasoline tank with a capacity of 500 ml. (2 kW saw power and average load lasts approx. 30-35 minutes). operation).

The gas tank consists of a housing, a cap and a breather hose

Throttle valve controls the quality of the injected fuel mixture

Ignition system consists of magnets integrated into the engine flywheel, ignition module with electronic circuitry and spark plug. Between the electronic unit, in which electrical impulses are induced, and the candle there is a high voltage wire.

2-cylinder terminal, 4-electronic unit, 5-wheel

Air is sucked into the carburettor through the air filter.

The air is cleaned by passing it through a thick synthetic fabric

chain, disassembled

Exhaust gases are extracted through the exhaust silencer.

A metal gasket is fitted under the silencer

No engine oiling system. A special 1/50 ratio of synthetic lube is added to the gasoline to prevent the cylinder walls, piston and crank mechanism from wearing out during operation.

Engine oil for two-stroke engines

The rapidly rotating chain requires lubrication. This is provided by a system for feeding oil into the chain drive channel. A pump at the base of the drive sprocket pumps lubricant from the oil reservoir. Comes in two types: piston or diaphragm type. Some models have a manual oil flow regulator.

The crankshaft and chain drive clutch is automatic. The sprocket begins to rotate when the number of engine revolutions increases. The chain saw is thus much safer to operate. if the chain jams in the wood, the clutch is released immediately.

Modern tools are equipped with additional systems that increase productivity and user safety. These include

  • Anti-vibration system. Reduces vibrations transmitted from the engine to the housing.
  • Chain braking system in case of kickback. Enhanced protection against sharp jerks of the body.
  • Relief in start-up and fuel system. Primer, decompression valve, spring starter.
  • Tool-free quick chain tensioning mechanism.
  • Additional air cleaning system in snowy, dusty conditions.

How to disassemble a Chinese chainsaw video

All gasoline-powered saws are structurally similar, so the causes of failure are the same for the expensive European Husqvarna unit, as well as for the popular cheap Chinese chainsaw “Champion 137. Repair with their own hands can be carried out only with knowledge of elementary laws of physics, the ability to read diagrams, drawings, and the presence of skills to work with mechanisms.

So, a chainsaw consists of:

  • Engine (mainly single-cylinder, two-stroke, carburetor);
  • The functional part (the saw part with the chain);
  • Service systems (starter, carburetor and other mechanisms).

Faults of the Chinese chainsaw: an overview of popular and ways to solve them

Buy a cheap chainsaw made in China is not very difficult: the markets, construction hypermarkets and online stores offer a huge number of chain saws from the Celestial Empire. However, the low price almost always hides a poor quality.

The most popular malfunctions of Chinese chainsaws should include:

  • Poor operation of the lubrication system. Clogged oil ducts should be cleaned, and if the oil pump is out of order, it should be replaced.
  • Starter cable break.
  • Breakage of the plastic starter shaft. An ordinary metal bolt will do for its replacement.

In the case of the slightest suspicion of improper operation of the chainsaw, it is worth to immediately make a complete diagnosis of the tool. Only with proper operation and timely maintenance can you count on a long chain saw’s longevity.

It would seem, why a chainsaw is necessary for a countryman, who grows vegetables and fruits, or a country house owner, who has a small garden and a few flowerbeds? The question falls away when there is a desire to build a bath house, upgrade a greenhouse, pile up an old case, or simply make a bench for relaxation. Unfortunately any mechanism periodically needs prophylaxis and replacement of spare parts, but for this purpose it is necessary to understand the device of the product well, moreover chainsaw repair with its own hands will save time and money.

Chainsaw failure typology

Before you disassemble the chainsaw you need to correctly determine the type of failure. Any malfunction of a chainsaw usually falls into one of two types. The first is engine failure. Problems occur in the ignition system, fuel supply, air supply, exhaust of air mixtures, cylinder-piston group.

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The second type. malfunctions in the other systems of the machine. These are breakdowns of the emergency brake, clutch, guide rail, lubrication system, and other parts.

A toolkit for making repairs:

Checking spark plugs

The first thing to do is to check the spark plugs. It is necessary to disconnect the wire suitable to the latter and unscrew it with a special wrench. By the condition of the spark plug you can determine the possible malfunction:

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  • a dry spark plug indicates that the ignition mixture does not enter the cylinder, the ignition system is not involved. The cause of the breakdown may be a clogged conductor tube or carburetor malfunction. It is necessary to clean the fuel line and check the fuel pump and carburetor. If one of the mechanisms does not work, it is necessary to replace it with a new one, as the repair of the latter in the absence of professional skills is impossible;
  • A wet spark plug indicates an excess of fuel mixture in the cylinder or water ingress. It is necessary to dry the spark plug, remove fluid residues and blow out the cylinder chamber. with the fuel supply turned off start the starter. Then place the spark plug and restart. When checking the gap between the electrodes should be measured, the acceptable value is from 0.5 to 0.65 mm. In case of damage or signs of wear and tear, the gasket must be replaced. If after all these operations the spark is good, there might be a problem with the quality of gasoline. Absence or irregularity. the problem is in the ignition. There is a possibility of damage to the supply wire or spark plug. If a new spark plug does not respond, it is necessary to inspect the starting system in more detail;
  • a spark plug with black soot deposits is a sign of poor-quality lubricant, “petrol-oil” imbalance in favor of the latter, one of the filters is clogged. Clogging leads to loss of power and then to chain saw shutdown. Dust doesn’t burn completely and settles on the cylinder walls in a black sludge layer. Change fuel, clean fuel filter, wash and dry air filter. Remove soot from the spark plug with an awl or a needle, and scrape the pins with light sandpaper.

Checking the fuel system

One reason for no fuel in the cylinder was already mentioned in the previous section. the fuel filter is dirty. check the filter by the intensity of a jet from the fuel hose, if it is weak the filter needs cleaning and if it is very worn out. change it completely. Air filter prophylactic change is recommended once in three months.

Poor fuel drainage can mean a clogged tank cap breather. Cleaning is done with an awl.

Another sign of malfunction is no or poor fuel mixture. It is connected with several possible reasons:

  • contamination of the air filter (wash and dry it afterwards);
  • problems with the carburetor. one of the options is possible: settings failure, damaged diaphragm, clogged channels.

The ability to adjust the carburetor by commoners is reduced to a minimum. the idle speed adjustment. But even properly tuning the latter, will significantly increase the power of your chainsaw. Plus, improper factory settings are possible, evidence of the latter are:

Solving Muffler Problems

If the engine stalls at increased operating speeds, the culprit may be a clogged muffler spark arrestor.

chain, disassembled
  • remove the muffler and plug the exhaust port;
  • If there is a constructive possibility. to disassemble;
  • Clean off soot with detergents;
  • dry out;
  • Assemble and reassemble.

Dry cleaning is not recommended because of the harmful impurities in the fouling. Use quality engine oils and pay close attention to the proportions in the fuel mixture to prevent contamination.

How to extend the life of your chainsaw

Have a pair of tires and at least four chains to spare. For even wear and tear, the chain should be turned 180 degrees after three hours of operation and replaced with a new chain after the same interval.

Timely cleaning of the tool ensures that there are no clogged holes, which can lead to difficulties or even interruption of the fuel mixture, which will affect the performance of the chainsaw.

If you are not confident in your abilities and are afraid of damaging your machine, it is better to call in professionals. They, by virtue of their experience, will always be able to correctly diagnose the problem and qualitatively fix your chainsaw malfunction.

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