A chainsaw is a device that is useful for every host. No matter what model you have a chainsaw, sooner or later you have to thoroughly study it in order to diagnose problems, repair the device yourself. Why is this necessary?
Of course, such a working tool is not safe from breakdowns, but some are not so serious that you contact a service center (where you have to leave a tidy sum). Sometimes a chainsaw can fail due to the banal clogging of the breather. Not sure where the breather on the chainsaw is? You will learn about this and much more from this article.
What is a breather?
This is a part that looks like a standard valve. It plays an important role. it normalizes the pressure in the tank of the chainsaw. Why is it important to normalize blood pressure? In order to answer this question, it is necessary to consider the process of vacuum formation in the tank. This happens when fuel is supplied during the hermetic closure of the gas tank (the pressure on the walls rises). Breather equalizes pressure (relative to atmospheric). Without this small valve, the importance of which many underestimate, proper operation of the chainsaw is impossible.
Husqvarna chainsaw owners can also read the manual. how to clean the carburetor correctly?
Where it is located?
Husqvarna chainsaw breather, as in models of different manufacturers, is in the tank. Sometimes it becomes clogged, which leads to problems with starting the tool or the chainsaw works intermittently or does not start.
How to fix the problem? Here are a few options:
- use compressor to clean;
- clean the small opening of the breather with a needle.
In both cases, you have to get to this detail. Given the structural features of chainsaws, in order to clean the breather, you will have to remove the handle of the device.
How to get to the breather?
You do not need special skill. The easiest way is to refer to the instruction manual of your model. Nevertheless, instructions for dismantling the handle can also come to the rescue.
To get started, pay attention to the preparatory phase.
- To carry out cleaning after dismantling the saw handle was easier, remove the bar and chain, side cover. This is optional, but desirable, because at the same time you can, using a brush and compressor, remove traces of oil, dirt, sawdust.
- Set the dismantled parts aside.
After cleansing, proceed to the removal of the handle.
- The handle is attached to the body with three shock absorbers (all rubberized), but they cannot be removed right away, so for starters we work with plugs made of plastic. Usually they are located in the inner cavity of each shock absorber.
- Take a powerful screwdriver and start squeezing the shock absorbers. Start with the one closest to the handle at the back.
- We remove two screws that will allow us to dismantle the wire rod (it is connected with the carburetor and the gas trigger, it is close to the handle where you removed the first shock absorber).
- At the end, you have a handle that is connected to the shock absorber. Now it remains to unscrew the case (break the inner part of the handle to the side).
- Remove the case from the gum. All is ready!
If you previously dismantled the chainsaw, handle the dismantling of the handle quickly.
Usually after this step the disassembly of the starter follows. But, given the standard structural features of the chainsaw, this step is not necessary for us to get to the breather. Optionally, you can remove the starter, as many sawdust accumulate under it.
Breather Cleaning Procedure
A simple cleaning method is to use a sewing needle. Before cleaning the valve, make sure that it is clogged. This is not difficult to do.
- Remove the carburetor (it must be disconnected from the fuel hose), estimate the number of traces of fuel.
- If the fuel escapes and the breather remains clean, then everything is okay with it and you need to continue the diagnosis. If a weak stream of fuel flows out of the gas line, you can be sure that the breather needs to be thoroughly cleaned.
Important! If after cleaning the chainsaw shows an increase in speed when idling, do not rush to panic and disassemble the tool or take it to the workshop. After cleaning, this behavior of the engine and carburetor (their interaction leads to an increase in idle speed) is considered the norm. If this feature is alarming, you can slightly adjust the idle screw located on the carburetor and marked T.
Is Sapun the culprit of problems with the chainsaw?
At the first sign of a broken chainsaw, do not rush to sin on the breather. Many do not want to immediately begin to disassemble the handle, if they are not completely sure that the culprit is the small valve. Before dismantling the chainsaw handle, exclude the probable causes of device malfunction so that the breather needs to be cleaned. Start small.
- Rate the quality of the fuel mixture. Not all manufacturers provide adjustable jets for chainsaw models. However, in some they can be configured. This gives the "masters" the opportunity to experiment with the composition of the fuel mixture. Perhaps you decided on such an experiment, but after a while you forgot about it, and now blame the tool’s gas tank breather for the tool malfunction. Remember that ideally you need to use the brand of oil recommended by the manufacturer (indicated in the instructions for the device), do not use the old mixture (you need to develop it in two weeks as much as possible). After a month, it will deteriorate and cause malfunctions in the operation of the device.
- Check the candle (perhaps at the time you start the tool you fill it). Inspect this part; it should be clean without a trace of oil. If there is plaque on it, then it should be light, brown indicates a problem with the ignition coil. Keep spare candles on hand to quickly remove this item from the saw problem list.
- Not only the breather can become clogged, but the carburetor jet and fuel filter (that is why after dismantling the handle must be removed and the carburetor to properly clean the surface under it from sawdust). With the cleansing of both nodes, you can handle it yourself.
- Clogged air filter. This filter can become clogged with dust, which will become the main obstacle when trying to start a chainsaw.
Consider the features of your tool model to be able to accurately diagnose the problem. This will help you not only eliminate it and return to working with a chainsaw as soon as possible, but it will save you from unnecessary fuss (dismantling those nodes that are not connected with a device malfunction).
Typically, a breather is integrated in the unit’s fuel tank cap, so you can easily get to it, and then quickly and efficiently clean the valve.
Why won’t a chainsaw start? Frequent malfunctions and methods for their elimination
Chainsaws are lightweight in design and reliable in operation.
With the correct appeal of the breakdown, they occasionally appear and are quickly eliminated if the owner knows where to find the reason.
And yet, the question of why the chainsaw does not start cannot be answered exactly. This tool in its own base is an ordinary two-stroke gasoline engine. For its normal operation, four conditions are needed: fuel, air, spark and lubrication.
Video: Where is the Husqvarna 142 Chainsaw
The carburetor is responsible for making the air-fuel consistency, the air cleans the filter from dust, the spark is made by the ignition unit and the spark plug, and the lubricant is in gasoline.
Reasons why a chainsaw refuses to start, must be found in turn, starting from the usual and moving on to more complex ones. Anyone who immediately rushes to disassemble the carburetor when the chainsaw starts poorly on a hot one is at a great risk. This unit is better to repair and adjust in a specialized workshop, and not on the knee.
By the way, some manufacturers of chainsaws so that users do not climb into the carburetor to change the composition of the fuel mixture, make the jets unregulated.
For trouble-free operation of the chainsaw, special attention must be paid to fuel. If the fuel mixture is improperly prepared, even a reliable Husqvarna will not start. In this case, the owner will begin to search for the cause of the malfunction anywhere, but not in the fuel. To eliminate this factor, you must always prepare the fuel mixture from high-quality gasoline and the type of oil that is indicated in the instructions.
You need to do it in such a quantity that in 1-2 weeks you can fully work out. If you keep her for a month in a canister, then gasoline will lose its octane qualities and problems with the saw are guaranteed.
Quite often, chainsaw malfunctions arise due to the filling of a candle gasoline at the time of launch. This problem is eliminated by twisting and drying the candle (without calcining!). Excess fuel is poured out through the candle hole, after which a 20-30 minute break is made, then the candle is put in place and the start is repeated. A good owner always has new candles in stock to exclude this item from the list of suspects when troubleshooting.
The absence of sparks is often caused not only by candle failure, but also poor contact between its tip and the high-voltage wire. If this connection does not raise suspicions during testing, but the spark does not appear when the starter is turned on, the electronic ignition unit is to blame. This unit is not being repaired, but is being replaced by a new one.
In addition to the above nodes, chainsaws have a cleaning system for the air supplied to the carburetor, a tire with a saw chain, a starter, a chain tension mechanism, ignition, a silencer, etc.
Engine
The chainsaw engine has a maximum speed of about thirteen thousand five hundred rpm. This imposes stringent requirements on the oil added to the fuel mixture.
Clutch
At low speeds, elements with friction pads (1), which have a degree of freedom in the radial direction, are attracted to the center of the shaft by springs (4.5) and do not transmit rotation to the drum (3) connected to the chain drive sprocket. When the revolutions of the chainsaw engine reach values, when the centrifugal force exceeds the force of the springs, the friction segments are pressed against the inner surface of the drum and do not start to rotate it. As a result, the drive sprocket starts to rotate, driving the saw chain.
As seen in the photo, asterisk is behind the clutch.
For other chainsaws, the sprocket may be on the outside of the clutch.
The main advantage of couplings of this type is that when the chain is jammed, the clutch of the chainsaw slips without dying the engine without causing damage to the mechanisms that transmit movement from the engine to the chain.
Ignition system
The electronic ignition of the chainsaw contains a flywheel (1) with built-in magnets, an ignition module (5) with an electronic circuit, a candle (3) not a high voltage wire (4). A rotating flywheel with magnets induces an emf in the module, which is converted by an electronic circuit into electrical signals supplied to the candle. In the course between the contacts of the latter, a spark flashes igniting the air-fuel mixture.
Carburetor
Below is a diagram of another carburetor chainsaw.
Carburetors have a throttle that allows you to impoverish, in other words enrich the mixture on the basis of working conditions. For fine tuning, there are several screws that adjust low low engine speeds, in addition to idling. An air filter is installed on top of the carburetor to clean the incoming air.
Fuel system
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So that during the consumption of the fuel mixture, the fuel tank is filled with air, negative pressure is not created here, which will not allow the fuel to enter the carburetor with its use, not in this case, so that fuel does not flow out of the air hole, in the lid that closes the filler hole, made a breather. Not when, if the breather clogs up with dirt, the chainsaw stalls.
From the tank, fuel is pumped through a hose freely hanging in the tank. Using this fact, regardless of the position of the chainsaw, the hose is always immersed in fuel. A fuel filter is attached to the inlet end of the hose. Fuel pumping pump inside the carburetor.
To facilitate starting, part of the chainsaws is equipped with a manual pre-pump. by primer. When starting a chainsaw with a primer, the carburetor is filled with fuel in advance (excess fuel flows back into the tank). Using this fact, the engine starts faster because the stage of filling the carburetor with fuel has already been completed, which without a primer is carried out by the carburetor pump through the use of a starter.
Air purification system
Pre-filters have a different design and do not consist of several elements, for example, from a mesh (2.4) non-snow (1) filter (see photo below).
The latter prevents the ingress of snow into the air purification system; it is not used only in winter; it is removed at positive temperature.
In some chainsaw models, pre-cleaning uses air purification using centrifugal forces. Chainsaw malfunctions Stihl ms 180 and where they are breather in a Stihl ms 180 chainsaw. The air flow is twisted by the flywheel impeller, and as a result, impurities are thrown away from the suction pipe going to the fine filter.
Fine filters are made of diffusion foam, nylon mesh and other materials.
During operation of the chainsaw, the air in the zone of its operation is heavily contaminated with sawdust, not wood dust. Excessive pollution of the filter reduces the amount of air entering the carburetor, which leads to the enrichment of the mixture does not decrease the power of the chainsaw. Therefore, regular cleaning of the filter is necessary. How oil should be carried out not so much when the chainsaw is disassembled for its repair, but much more often, after any lengthy non-dirty work. Cleaning is carried out by a method that depends on the type of filter material. more often than not by flushing.
Fuel tank check valve
No installation replacement process breather no fixation plugs chainsaw breather Husqvarna (Husqvarna) 236, 240.
Starter
The starter mechanism consists of a drum (1) with a cable (5) not a handle (3), not a frame (4) with a return spring. When the handle is pulled up sharply, the ratchet of the drum engages with the teeth on the motor shaft and does not crank the crankshaft. When you release the handle, the return spring returns it to its original position.
The main not the most complex links in the chain are cutting links, which are divided into right-handed non-left-handed. The upper edge of the tooth. the widest of all the elements. Like oil provides a wide cut, eliminating the jamming of the remaining links.
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The shape of the cutting teeth can vary significantly between chains of different manufacturers. There are two main forms. Chipper (a) not chisel (b). However, there are no different intermediate contours of the incisors.
Tooth cutting edges. lateral not upper. sharpened at a certain angle. For chains of longitudinal sawing it is 10 °, for transverse. 30 °. Longitudinal chains are rarely used. If the passage is necessary, the longitudinal sawing is performed not with a cross-cutting chain. Read more about the angle of sharpening chains of chainsaws, read the text of the article Sharpening chains of chainsaws.
The main characteristic of a chain is its step. To establish the chain pitch, the distance between the midpoints of the first and third connecting rivets is measured (see the figure below). This size is not divided in half. The result obtained. chain pitch in mm. However, in the bulk, the chain pitch is set in inches. The distance between the middle of the first and third connecting rivets is measured since the distance between the holes leading links non-cutting links as it is also called connecting links vary in magnitude. The most common chains in increments of 0.325 are not 3/8 inches (8.255 are not 9.525 mm, respectively). Chains with a pitch of 0.325 are used with engines of low power (up to 40-50 cm three), although powerful chainsaws are usually equipped with 0.404 inch chains (such chains have higher performance). Do-it-yourself Husqvarna 142 chainsaw repair there is a breather on the. The cut turns out to be cleaner and not neat, if you use a chain with a smaller thickness of the link with no less step when sawing.
Important characteristics include shank thickness. There are five standard thicknesses: 1.1, 1.3, 1.5, 1.6 not two mm. The most common are chains with a liner thickness of 1.3 mm (0.05") They are widely used both on household and non-professional chainsaws. The thickness of the guide links must be matched to the width of the groove in the guide bar, so that the saw chain fits the guide bar exactly.
To guide the chain, the tire has a guide groove at its periphery when the chain drive links are moved. The groove in the groove serves as a conduit for oiling the chain. The main parameters of the tire include:
- Connection hole sizes (a), depending on type chainsaws.
- The width of the groove (b), which should correspond to the thickness of the shanks of the chain used. The width of the groove of the tire by only a few hundredths of a millimeter is not easy than the thickness leading links appropriate saw chains. For this reason, precise lateral guiding of the saw chain is achieved.
- The sprocket pitch (c) also determines the compatibility of the circuits used with the bus.
- Cutting length (g), which determines the size of the processed material. tree trunk diameter, etc.
Chain brake
Turning on the brake circuit you like contact pin is not inertia. The first occurs when the brake stop (1) is pressed on the worker’s hand, which occurs spontaneously when the saw is thrown away. The displacement of the stop that occurs here causes the brake band (2.4) to tighten on the clutch drum not to stop, and as a result, the non-saw chain stops.
The inertial brake application is based on the inertial forces arising from a sharp blow to the tire acting on the brake elements, which leads, among other things, to a result that is not at the beginning. tightening the brake band while stopping the chain. Inertial brake application is faster than contact. However, the second is more reliable. Any preparation for work, in addition the assembly of a chainsaw after its repair or maintenance, is made to end with a check of the operation of the chain brake. If it does not work, the saw is considered malfunctioning.
Chain tensioning mechanism
For added convenience, the chain tension screw can be positioned on the side.
Chain lubrication system
Oil pumps have a different design (piston in a different diaphragm type) are not made of different materials (metal, in other words plastic). They are driven by a gear train, which receives its professionalism from a driving sprocket. When the engine is idling (the drive sprocket does not rotate the chain), oil is not supplied. Pump performance depends on the number of revolutions of the drive sprocket, the higher they are, the more that oil does not just enter the saw chain. Some oil pumps have a manual capacity adjustment mechanism. by means of the adjusting screw (1).
Video demonstrating a chainsaw device: