In addition to the listed units, chainsaws have a system for cleaning the air supplied to the carburetor, a tire with a saw chain, a starter, a chain tensioner, ignition, a muffler, etc.
The chainsaw engine has a maximum speed of about 13,500 rpm. This imposes strict requirements on the oil added to the fuel mixture.
At low speeds, elements with friction lining (1), having a degree of freedom in a circular direction, are attracted to the center of the shaft by springs (2) and do not transfer rotation to the drum (3) connected to the driving chain sprocket. When the speed of the chainsaw motor reaches values at which the centrifugal force exceeds the force of the springs, the friction segments are pressed against the inner surface of the drum and begin to twist it. As a result, the drive sprocket begins to spin, driving the saw chain.
As you can see in the photo, the sprocket is behind the clutch.
On other chainsaws, the sprocket may be on the outside of the clutch.
The main advantage of clutches of this type is that when the chain is jammed, the chainsaw clutch slips without muffling the engine and without causing breakage of devices that transmit movement from the motor to the chain.
The electric ignition of a chainsaw contains a flywheel (1) with built-in magnets, an ignition module (2) with an electrical circuit, a spark plug (3) and a high voltage wire (4). A spinning flywheel with magnets induces an electromotive force in the module, which is converted by means of an electrical circuit into electronic signals supplied to the spark plug. As a result, a spark jumps between the contacts of the latter, igniting the air-fuel mixture.
Below is a diagram of another chainsaw carburetor.
Carburetors have a throttle valve that allows leaning or enriching the mixture, depending on the criterion of work. For a narrow option, there are a number of screws, with the help of which the adjustment of low and high engine speeds, also idle speed, is made. An air filter is installed on top of the carburetor, cleaning the air entering it.
So that as the fuel consistency is consumed, the fuel tank is filled with air and a negative pressure is not created in it, which will not allow fuel to flow from it into the carburetor, and with all this, so that fuel does not flow out of the air hole, in the cap that closes the filler hole, breather made. How to replace oil seals on a chainsaw. How to remove the sprocket, clutch and flywheel on. And by the way, if the breather gets clogged with dirt, the chainsaw will stall.
From the tank, the fuel is pumped through a hose freely dangling in the tank. Thanks to this, regardless of the position of the chainsaw, the hose is always submerged in the fuel. How to remove the clutch on a chainsaw | tools in. A fuel filter is attached to the inlet end of the hose. The fuel is pumped from the inside of the carburetor.
To facilitate starting, some of the chainsaws are equipped with a manual pump for preparatory pumping - a primer. When starting a chainsaw with a primer, the carburetor is filled with fuel in advance (excess fuel flows back into the tank). Thanks to this, the engine starts faster, because the stage of filling the carburetor with fuel has already been passed, which, without a primer, is produced by the carburetor pump at the expense of the starter.
Preparatory filters can have different designs and consist of several parts, namely, a mesh (2) and snow (1) filter (see photo below).
The latter prevents snow from entering the air cleaning system and is used only in winter, at positive temperatures it is removed.
In some models of chainsaws, at the stage of preparatory cleaning, they use air cleaning using centrifugal forces. The air flow is twisted by the impeller of the flywheel, as a result of which the impurities are thrown away from the suction pipe that goes to the narrow filter.
Narrow filters are made of diffusion foam, nylon mesh and other materials.
When the chainsaw is working, the air in the zone of its action is very dirty with sawdust and wood dust. Excessive contamination of the filter reduces the volume of air entering the carburetor, which leads to a richer consistency and a drop in the power of the chainsaw. removing the clutch from the partner p340s chainsaw. How to remove the clutch on a chainsaw. Therefore, constant cleaning of the filter is needed. It should be carried out not only when the chainsaw is being disassembled for the purpose of repairing it, but even more often, after any long and dirty work. clutch burned out how to change an asterisk on a chainsaw easily and effortlessly. Cleaning is done in a way that depends on the type of filter material - in most cases by blowing and rinsing.
VIDEO
Chainsaw clutches Ural - setting and all aspects. I carefully show how to set up correctly clutch .
The starter mechanism consists of a drum (1) with a cable (2) and a handle (3), and a frame (4) with a return spring. When the handle is pulled up sharply, the drum ratchet engages the teeth on the engine shaft and turns the crankshaft. When the handle is released, the return spring returns it to its original position.
It takes a certain amount of effort to crank the crankshaft at the speed at which the engine starts. It is often not possible to start the chainsaw with one jerk, you have to jerk it several times. To facilitate starting, various methods are used - enriching the fuel mixture using the carburetor flap, or reducing the pressure in the cylinder using a decompression valve (to facilitate crankshaft rotation). clutch burned out how to change an asterisk on a chainsaw how to adjust. The valve is made to automatically close when the pressure in the cylinder rises when the mixture is ignited. how to remove the chainsaw clutch - duration: the oil on the chainsaw is not the chainsaw partner is not. Sometimes an additional spring is used in the starter mechanism, which, when the cable is pulled out, is first compressed and then abruptly unclenched, spinning the motor.
The main and most complex chain links are cutting links, which are subdivided into right-handed and left-handed. The top edge of a tooth is the widest of all elements. It provides a wide kerf to prevent the remaining links from getting stuck.
The shape of the cutting teeth can vary significantly from chain to manufacturer. There are two main forms - chipper (a) and chisel (b). However, there are also different intermediate contours of the incisors.
The cutting edges of the tooth - side and top - are sharpened at a specific angle. Often, people who use chainsaws in their work, during the maintenance process, have a question about how to remove the clutch on a chainsaw. It is 10 ° for rip sawing chains and 30 ° for rip sawing. Rip saw chains are rarely used. If necessary, rip sawing can also be done with a cross saw chain. For more information about the angles of sharpening chainsaw chains, read the article Sharpening a chainsaw chain.
The main characteristic of a chain is its pitch. To establish the chain pitch, measure the distance between the centers of the first and third connecting rivets (see.picture below) and this dimension is halved. The result is the chain pitch in mm. However, in most cases, the chain pitch is specified in inches. The distance between the midpoints of the first and third rivet rivets is measured because the distance between the holes of the driving links and the cutting links or connecting links can vary in magnitude. The most common chains are 0.325 and 3/8 inch (8.255 and 9.525 mm, respectively). Chains with a pitch of 0.325 are used with low-power engines (up to 40-50 cm 3), while powerful chainsaws are usually equipped with 0.404-inch chains (such chains have a higher performance). A cleaner and more accurate cut is achieved by using a chain with a smaller link thickness and a smaller pitch.
Shank thickness is an important characteristic. There are five standard thicknesses: 1.1, 1.3, 1.5, 1.6 and 2 mm. The most common are chains with a shank thickness of 1.3 mm (0.05). How to remove the clutch on any brand of chainsaw. One of the most important parts of any device model is the clutch. They are widely used on both household and professional chainsaws. The thickness of the drive links must be matched to the groove width of the guide bar so that the saw chain fits perfectly on the guide bar.
Chain manufacturers use different technologies for their manufacture and use different materials. The defining characteristic of the latter is not hardness (teeth that are too hard do not lend themselves well to manual sharpening), but toughness and impact resistance. how to remove the clutch from the disassembly of a chainsaw cleaning the carburetor in the Chinese. Clutch at all in order to correctly assemble a partner 350 in a chainsaw, as in. It is they who determine the durability of the chain. Therefore, wear-resistant alloy steels are used in the manufacture of cutting teeth. Cutters are often chrome plated to increase their surface hardness. Some firms use shot blasting to increase the toughness of the teeth.
To guide the chain, the tire has a guide groove on its periphery, in which the driving links of the chain move. The groove of the groove also serves as a channel for supplying oil for lubricating the chain. The main parameters of the tire include:
Dimensions of connecting holes (a), depending on the type of chainsaw.
The width of the groove (b), which should correspond to the thickness of the shanks of the chain used. The groove width of the bar is only a few hundredths of a millimeter wider than the thickness of the drive links of the respective saw chains. This ensures precise lateral guidance of the saw chain.
The pitch of the end sprocket (c), which also determines the compatibility of the used chains with the bus.
The length of the cut (g), which determines the size of the processed material - the diameter of the tree trunk, etc.
The activation of the chain brake can be contact and inertial. The first occurs when the brake stop (1) is pressed on the worker's hand, which spontaneously occurs when the saw is thrown back. The resulting displacement of the stop leads to the tightening of the brake band (2) on the clutch drum and to its stopping, as a result of which the saw chain also stops.
The inertial activation of the brake is based on the inertial forces arising from a sharp impact on the tire, acting on the brake elements, which leads to the same result as in the first case - tightening the brake band and stopping the chain. Inertial brake engagement is faster than contact engagement. How to remove a chainsaw clutch. 1. In order to remove the clutch on the chainsaw. However, the second is more reliable. Any preparation for work, as well as the assembly of the chainsaw after its repair or maintenance, must end with a check of the chain brake. If it does not fire, the saw should be considered defective.
For added convenience, the chain tensioning screw can be located on the side.
Oil pumps have different designs (piston or diaphragm type) and are made from different materials (metal or plastic). They are driven by a gear train, which receives its movement from the drive sprocket. When the engine is idling (drive sprocket and chain do not rotate), oil does not flow. Chainsaw grip how to change a star on a partner? The video will help you change the presenter. The pump performance depends on the number of revolutions of the drive sprocket, the higher they are, the more oil goes to the saw chain. How to remove the clutch on a chainsaw of different brands. Some oil pumps are equipped with a manual capacity control mechanism - using an adjusting screw (1).
A video demonstrating the chainsaw device:
Chainsaw clutch malfunctions are one of the most common failures of this technique. The question of how to remove the clutch on a chainsaw at home correctly and not harm the tool is thought not only by inexperienced technicians, but also by specialists who have repaired it more than once. This is due to the fact that the clutch is an important key element of chainsaws of any power class and brand, on which their serviceable, long-term and successful operation depends.
In cases where gasoline cutters start to start badly, slip instead of starting, checking the clutch for faults is mandatory, recommendations regarding which will be presented later.
Modern chainsaws are equipped with centrifugal clutches. This means that their work is entirely dependent on the torque of the motor, which the saw gives out at a particular moment in time.
Its main structural elements are:
The principle of operation is as follows. When the saw is started, the elements that move freely in the radial direction are pulled together by springs to the shaft axis. In this case, the torque does not go to the drum, which means to the sprocket and the guide. At the moment when the centrifugal force prevails over the force potential of the springs, the clutch elements weaken and compress at the inner part of the drum, initiating its torsion. Together with it, the rotational cycle passes to the sprocket and the tire-chain set itself.
The main advantage of this type of clutch is its slippage when the cutting part is suddenly braked, which does not stop the engine. As a result, the "heart" of the saw - the motors remain safe and sound.
The clutch repair process consists of the following operations:
dismantle the chain set, air filter flaps and the clutch itself;
lock the crankshaft - for this it is enough to simply unscrew the ignition cut;
unscrew the clutch with a special wrench with strong movements clockwise or counterclockwise (different saw models can have both left and right threads). Usually, a tool for removing the clutch is included with the chainsaws;
go to disconnecting the drum and sprocket;
if, when inspecting the clutch, one or several cracked springs were found (there may be several of them, for example, for Husqvarna chainsaws - 3 units), a broken spring needs to be replaced with a new one;
assemble the clutch on the chainsaw, put it in place and screw it in. Remember that the crankshaft must still be stationary;
mount the removed parts on the saw in the reverse order to disassembly;
fix the clutch - move the auxiliary brake handle forward, start the device and carefully remove it from the inertia brake.
When servicing clutches yourself, you need to know that:
several saws have a washer that sits between the sprocket and the clutch and the sprocket and the motor. Consider this when repairing;
the special spring of the oil pump drive must not be damaged during disassembly, and must also be returned to its original position. Otherwise, the chain will receive less lubrication or no longer lubricate at all.
The tool that has been repaired must be checked for the reliability of the bolt ties, the supply of lubricant to the chain and the serviceability of the motor (it must turn on smoothly and work smoothly). Only then can it be exploited.
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1) Malfunction chainsaws: The chain rotates almost constantly (the engine, at the same time, may not work stably). Causes Faults: The clutch spring has burst. Repair DIY chainsaws: Replace the broken clutch spring with a new one (for details, see below "How to remove the chainsaw clutch"). Husqvarna's chainsaws have one clutch spring and two weights, while Calm chainsaws have three clutch springs and three weights (cams, sectors). If you cannot find the clutch spring itself, you will have to change the entire clutch.
2) Malfunction chainsaws: The chain rotates almost constantly, sometimes extraneous sounds are heard in the clutch. Causes malfunctions: The clutch cam broke off (due to overheating) and the clutch spring flew off. Blue clutch cams indicate overheating. Overheating right before the clutch breaks can occur if you operate the chainsaw with the chain brake or a dull chain on. Repair DIY chainsaws: Replace the clutch assembly (see details below "How to remove the chainsaw clutch").
3) Malfunction Chainsaws: The clutch often "slips", sometimes the spring bursts. Causes malfunctions: Chainsaw clutch worn. Repair DIY chainsaws: Replace the chainsaw clutch assembly.
1. In order to remove the clutch on a chainsaw, you must first remove the cutting attachment, then the air filter cover and the clutch cover.
2. Then you need to lock the crankshaft so that it does not rotate when the clutch is unscrewed. To lock the crankshaft, for example, with a large knob, you need to remove the recoil starter cover and screw two bolts into the rotor of the ignition system. Or unscrew the spark plug, lower the piston to BDC and lock it there by pushing a rope into the spark plug hole.
3. Next, unscrew the clutch itself - using a key from the chainsaw kit, or a key for the grinder's discs, or a homemade key (for example, from an old tire with two bolts), unscrew the clutch clockwise (there is a left-hand thread) in order to disrupt a significant effort.
4. Then remove the drum with the drive sprocket from the chainsaw. Chainsaw clutch drum replacement is performed according to the rule: if you replace two tires, replace one drum.
5. Then put on the new clutch and tighten it by hand until it stops (screwed counterclockwise). In this case, it is necessary to stop the crankshaft again so that, when turning the clutch, you do not break the starter located at the other end of the chainsaw crankshaft.
6. Then everything is assembled in the reverse order of disassembly.
7. To tighten the clutch on the chainsaw completely, you need to move the chain brake handle forward, start the chainsaw and then release the brake.
When the chainsaw is idling, the clutch weights, although they rotate with the crankshaft, do not touch the clutch drum (popularly, the clutch cups) as they are tightened by a spring and, accordingly, do not transmit torque from the engine to the saw headset.
Often, people who use chainsaws in their work, during the maintenance process, have a question about how to remove the clutch on a chainsaw. The fact is that this unit of the chainsaw mechanism requires constant monitoring of its operability, which, in turn, requires periodic disassembly for preventive maintenance and repair.
Chainsaw device diagram.
It is worth noting that all chainsaws are classic devices driven by a gasoline engine.
Chainsaw electronic ignition circuit.
In the device of chainsaws, single-cylinder engines running on high-octane gasoline have been used. The power unit does not have a gearbox. It is a single-stage transmission that drives the chain. The simplicity of the design is the key to the reliability and trouble-free operation of the tool, even in the presence of severe operating conditions.
In addition to these units, the design of the chainsaw includes an air purification system that is supplied to the engine for preparing the combustible mixture, a tire with a saw chain installed on it, a starter that starts the chainsaw's power plant, a chain tensioning mechanism, an ignition system, and an exhaust suppression system. In addition, the design of the chainsaw includes the so-called emergency brake, the actuation of which allows in an emergency to instantly disconnect the power plant of the chainsaw from the drive sprocket to prevent injury to the person operating the device.
Types of spark plugs for chainsaws.
In modern chainsaws, a two-stroke single-cylinder carburetor-type power plant is installed.
The engine consists of several systems and components that make up a single whole. In the design of the engine, several elements can be distinguished that ensure its functioning:
flywheel;
clutch;
ignition module;
muffler;
special sleeve for mounting the carburetor.
Engines installed on chainsaws are high-speed. The maximum number of revolutions of the power plant is 13,500 rpm, which requires the use of high quality oil for engine lubrication, which is added to the fuel mixture.
Since the operation of chainsaws is carried out, as a rule, in difficult conditions, good cooling is required for the power plants of the device. The engines used to install the chainsaw are power plants equipped with a forced cooling system. For this purpose, an impeller in a closed housing is installed on one of the crankshaft semiaxes. Due to the rotation of the impeller, air is supplied to cool the cylinder of the power plant through the corresponding air duct.
Chainsaw fuel system: 1 - fuel filter, 2 - carburetor, 3 - manual pre-priming pump.
The carburetor in the power plant device is designed to prepare and feed a combustible mixture into the cylinder. Most often, carburetors produced by manufacturers such as Walbro, Zama and some others are used in chainsaws. A special filter is mounted on top of the carburetor for cleaning the air supplied to the carburetor. The fuel system in its simplest form consists of a tank, a filter element, and a fuel supply hose. Typically, a fuel tank is sufficient to operate for 30-40 minutes.
To fill the tank with air during operation of the device, its lid has a breather, which lets air into the tank and prevents fuel from flowing. If the breather becomes clogged with debris, the engine stops working. A fuel filter is installed at the end of a loose hose. Fuel injection occurs due to the operation of a pump located inside the carburetor.
When the power plant is operating, atmospheric air must be supplied to it for the preparation of a combustible mixture in the carburetor. The incoming air is cleaned with a special air filter. As a rule, two filters are installed in the construction of a chainsaw: a coarse filter and a fine one.The pre-filter has several elements and prevents large contaminants from entering the engine. A fine filter removes dust particles from the air. In some models, a flywheel impeller is used as a cleaning element, which cleans the air stream from large impurities due to centrifugal forces. In the manufacture of fine filters, diffuse foam rubber, nylon mesh, or some other materials are used as a filtering element. The chainsaw filter requires regular cleaning.
Chainsaw two-stroke engine diagram.
Today, gasoline-powered saws are equipped with electronic ignition units, which do not require adjustment and cleaning. The ignition system includes a flywheel with magnets, a module with an electronic system, a spark plug and a high-voltage wire.
A starter mounted on the device is used to start the saw engine by turning the crankshaft. The starter mechanism includes the following elements:
drum;
cable with a handle;
frame;
return spring.
When the cable is pulled sharply, the starter ratchet engages with the crankshaft teeth, which leads to its turning. The return spring is designed to return the cable to its original position. To start the power plant, a certain force is required, since the engine starts only at a certain speed of rotation of the crankshaft.
The design of the chainsaws is equipped with a centrifugal clutch, which works automatically, depending on the amount of revolutions of the engine crankshaft.
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At low revs, the elements installed in the clutch basket and having special overlays are attracted to the center of the shaft by springs. This position of the elements prevents the transmission of rotary motion from the crankshaft to the sprocket. When a certain number of revolutions of the power plant is reached, the elements with special pads diverge and are pressed against the clutch drum, transferring rotation to the chain. The main feature of such a clutch is that it starts to slip when the saw chain stops, which avoids breakdown of the power plant and mechanisms that transmit movement to the chain. Quite often, the clutch, as a result of intensive use, needs to be subjected to preventive maintenance and repair. For this purpose, the clutch is disassembled.
The clutch drum is also the driving sprocket.
This structural element is consumable, and this, in turn, requires regular replacement or repair.
File position when sharpening the chainsaw chain.
The main reason for the failure of this unit is the wear of the sprocket teeth. If the drum is monolithic, then during operation the chain cuts the sprocket. This drum must be replaced. On some drum devices, there is a replaceable rim and during repairs it is replaced, and the drum, while maintaining its normal state, is operated further.
If it is necessary to repair the chainsaw, the question arises of how to disassemble the clutch. If you have a service center, it is better to contact specialists, but in the absence of the latter, the disassembly and repair procedure can be carried out with your own hands. This operation is uncomplicated and, with the appropriate tools, it can be performed by almost everyone. Almost every model of this tool has its own nuances in carrying out the dismantling of the clutch, but the general sequence of actions is the same for all models.
The first step is to remove the chain brake cover. For this purpose, you need to pull the handle towards you. This is to ensure that the tape does not come into contact with the clutch cup. After that, the cover nuts and the chain tensioner are loosened.
Loosening the tensioner will loosen the chain and bar. After that, the nuts securing the brake cover are unscrewed, after which the cover is completely dismantled.
At the second stage, the guide bar and chain are dismantled, dirt is removed.
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The next stage of disassembly is to unscrew the cylinder head plug. Then the piston is fixed in the cylinder. For this purpose, the crankshaft is rotated and after closing the outlet, a piece of rope is lowered into the cylinder, which prevents further movement of the piston. After the repair, the rope is pulled out at the other end.
The fourth stage of disassembly is the direct dismantling of the clutch. First you need to unscrew the nut on the clutch. It should be remembered that this one has a left-hand thread; when unscrewing it, you need to turn the key clockwise. For work, a key is used, which is included in the chainsaw accessory kit.
After unscrewing the nut, you need to disassemble the clutch and inspect the drum with the drive sprocket for wear. Then, after inspecting the drum and sprocket, the condition of the needle bearing is inspected. If necessary, worn-out elements must be replaced.
The assembly of the tool is carried out in the reverse order.
There are several nuances that you need to know when repairing a clutch:
On some modifications and models of chainsaws, a washer is placed between the clutch and the drive sprocket cup. In the case of disassembling this element, the washer must be installed in the position in which it was previously. This washer can sometimes be fitted between the motor and the cup.
Some models of oil pump drives have a special spring. It transfers rotation from the sprocket to the oil pump drive. Correct installation of this spring is very important when assembling the device. If installed incorrectly, the oil pump stops supplying oil to lubricate the chain. Which can lead to costly repairs.
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After carrying out repair work, before using the chainsaw for its intended purpose, it is required to check the operation of the oil pump and the supply of oil to them for lubricating the saw chain and the mechanisms of the guide bar.
Many users are interested in the question of how to remove the clutch on a chainsaw. This will require special tools and a repair manual.
The chainsaw device includes a clutch mechanism, which consists of elements such as:
crankshaft;
driven disk;
pressure disk;
protective cover of the mechanism;
release lever;
bearing;
inclusion plug;
crankcase;
gears;
pipeline;
fasteners.
At minimum revolutions of the power unit, the chainsaw clutch is attracted to the center of the shaft by a spring device and does not transmit torque to the drum. At a time when the engine speed begins to reach indicators at which the breakout force exceeds the force of the spring device, the friction-type segments begin to press against the inner surface of the drum mechanism, which contributes to the rotation of the Chinese chainsaw drum.
During this, the drive sprocket begins to rotate, which is responsible for moving the saw chain.
Do-it-yourself repair of the chainsaw clutch is carried out only in special protective clothing: a mask and glasses.
Main malfunctions, their causes and remedies:
If the chain mechanism constantly rotates during unstable operation of the power unit. This could be caused by a broken spring. In this case, it is recommended to replace the damaged mechanism with a new one.
During the movement of the chain, extraneous noise is heard. This problem could be due to overheating of the knuckle or a broken spring. It is necessary to conduct an external inspection of the system and replace all worn out elements.
If the breakdown is due to the fact that the hitch often slips, you need to completely replace the mechanism.
In order to replace this mechanism, it is necessary to dismantle the old hitch. During repair work, the saw must be securely fixed on a non-slip surface using special devices.
During the dismantling and installation of the clutch, it is recommended to take into account the following nuances of such work:
On some versions of the tool, a washer is located between the hitch and the drive gear cup. Therefore, at the end of the repair, it is necessary to install this element in place.
Some oil lines have a special spring. It is mounted between the sprocket and the oil pump drive. It also needs to be properly reinstalled after replacing the hitch.
In order to remove and disassemble the clutch, you need to install the chainsaw on a flat, non-slip surface and secure it with fixing elements.
First you need to unscrew the saw chain and bar using the universal wrench. Then you can remove the cover from the air filter element. Then you need to remove the spark plugs, and fix the piston part in the master cylinder.
Then install a suitable puller and unscrew the clutch.
After the actions taken, remove the clutch drum on the chainsaw and the clutch. At the end, you can conduct an external inspection of the system for damage and defects and, if necessary, replace the failed parts with new ones.
In order to assemble the mechanism back, it is necessary to install the clutch in place and fix it with a special handle. The saw motor must be turned off at this moment.
After that, the spring device, drum mechanism and sprockets can be installed in place.
All parts must be securely fixed with fasteners.
Then you can install the clutch mechanism back into the tool body, remove the crankshaft from the stopper, install the filter mechanisms, the throttle valve and the step with the chain in place.
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At the end of the work, it is recommended to start the chainsaw and check the performance of the assembled clutch. If all parts are installed correctly, the clutch will engage immediately, there will be no delays or leaks.
It would seem, why does a chainsaw need a summer resident who grows vegetables and fruits, or the owner of a country house who has a small garden and several flower beds? The question disappears when there is a desire to build a bathhouse, update a greenhouse, throw down an old business, or just make a bench for relaxation. Unfortunately, any mechanism periodically needs prophylaxis and replacement of spare parts, and for this you need to be well versed in the device of the product, besides, repairing the chainsaw with your own hands will save time and money.
All chainsaws are similar in structure, regardless of whether they are European (ECHO, Stihl, Husqvarna) or domestic (Kedr, Ural). The main elements are located inside the body - the fuel tank and the engine, and outside the starter, the handle, the saw part (tire) with the chain. A sharp jerk in the cable starts the engine, which starts the saw blade.
To begin with, we suggest that you familiarize yourself with the video clips that show how the chainsaw works and how it works:
From time to time, the saw malfunctions, which require disassembly to eliminate. What can happen to such a simple mechanism as a chainsaw? At least the following:
Stops getting started;
Starts up, but soon stops;
Ceases to function in the cut;
Loses its power;
Most of the malfunctions are associated either with interruptions in the operation of the engine (fuel supply system, exhaust system, ignition, cylinder-piston part), or with malfunctions of other systems and assemblies (clutch, chain brake, tire, lubrication system).Consider the most common breakdowns and techniques for their elimination.
A serviceable chainsaw starts with one jerk and does not fail in the cut
The first thing to do if a chainsaw breaks down is to inspect the spark plug by disconnecting the wire and carefully unscrewing it with a special key.
The components of the chainsaw ignition system: 1 - flywheel with magnets, 2 - ignition module, 3 - spark plug, 4 - high voltage wire
Unscrew the spark plug to check its condition.
Her appearance says a lot:
Dry. Most likely, the fuel mixture does not enter the cylinder. It's not about the ignition system, so the plug is screwed back in.Strongly splashed with fuel. The reason for the excess fuel mixture lies either in the violation of the starting rules, or in the incorrect adjustment of the carburetor. The spark plug is carefully wiped, shut off the fuel supply and turn on the starter - to remove excess fuel and ventilate the combustion chamber. Then the candle is put in place and the mechanism is started again.Covered with black carbon. This may indicate the use of low-quality oil, an incorrectly adjusted carburetor, or an incorrectly calculated gasoline to oil ratio. The candle should be washed, cleaned of carbon deposits with a sharp object (awl or needle), wipe the electrodes with a sandpaper and put in place.When checking the candle, you need to pay attention to the gap between the electrodes: it is considered normal from 0.5 to 0.65 mm. A damaged or worn gasket must be replaced.
A large amount of black carbon on the spark plug indicates a malfunction of the engine.
To be sure, you should also check for a spark. To do this, put the ignition cable on the spark plug, connect the plug nut and the cylinder with pliers, start the starter and watch for the spark. If it is missing, the plug must be replaced. If the new spark plug also does not emit sparks, the problem is in the high-voltage wire or in the broken connection with the spark plug.
Fuel may not enter the cylinder for the following reasons:
Dirty fuel filter. Remove the fuel hose and check how the fuel flows. If the jet is weak, the filter may need to be cleaned. It is taken out through the filler hole of the fuel tank and cleaned; in case of severe contamination, it is replaced with a new one. As a preventive measure, it is recommended to replace the fuel filter every three months.Clogged breather (holes in the fuel tank cap). It is also checked by disconnecting the hose, in case of blockage, clean it with a needle.Lack or insufficient amount of fuel. There may be several reasons for the malfunction. The first reason is a clogged air filter. Air ceases to flow into the carburetor in the required amount, in this regard, due to a too rich fuel mixture, engine operation is disrupted. The contaminated filter is carefully removed, cleaned and washed in water, then dried and reinstalled.Another reason is improper adjustment of the carburetor. The adjustment is made with three screws.
Timely replacement of the fuel filter ensures full fuel supply
The fuel hose and choke actuator must fit snugly on the fittings
The throttle lever cable must be in place
During work, you must use the instructions, otherwise you can only make it worse.
And the last reason is a violation of the integrity of the membrane or clogging of the carburetor channels.
To repair the carburetor yourself, you need to get acquainted with all its parts.
All parts must be clean, dry and in good condition.
If the engine works fine at low speeds, and at high speeds it starts to stall, the reason may lie in the muffler spark arrester, clogged with combustion products.
remove the muffler;
disassemble (there are also non-separable models);
remove carbon deposits using detergents;
dry with a hairdryer;
install in place.
Dry cleaning is unacceptable, as the soot contains carcinogens, the inhalation of which is hazardous to health. After removing the muffler, cover the outlet with a clean cloth.
Interruptions in the operation of the chainsaw signal a possible clogging of the muffler
To avoid clogging of the muffler, it is necessary to monitor the composition of the fuel mixture. The amount of oil should not exceed the rates recommended by the manufacturer. Poor oil quality also negatively affects engine performance.
Often the engine will not start or run at full capacity due to low cylinder pressure. It can be caused by piston or cylinder wear, piston ring sinking, bearing wear. You can partially examine the state of the cylinder-piston group (CPG) by removing the muffler and looking into the opened hole.
A compressor placed in the spark plug hole will help to measure the compression in the engine - according to the measurement results, you can also talk about the state of the CPG. Accurate data is obtained only after complete disassembly of the mechanism. If the piston is chipped or scratched, it must be replaced. The piston ring must be clean, free of carbon deposits, and be exactly in place.
Piston and crank mechanism wear is considered a serious problem.
According to the results of measuring the compression, one can judge the condition of the parts of the CPG
Let's consider three main faults:
Oil leakage. Check that the pipes are tightly connected to the pump unions and that they are not cracked. Problem tubes are sealed with sealant or replaced.
Insufficient oil supply. Most likely, the lubrication passages are clogged.
Cracks in the oil pump housing. Part needs to be replaced.
Here's how to diagnose the lubrication system:
The chain brake often does not work due to clogging of grease or sawdust in the brake band and the space under the cover. All parts should be cleaned from blockages. Perhaps the tape is simply worn out, then it needs to be replaced.
The chain brake is restored by mechanical cleaning
Video (click to play).
Some parts of a chainsaw will wear out faster than others. These include the drive sprocket, bar, chain, anti-vibration elements. For quick replacement, it is best to always have spare parts on hand. Sharpening the chain should not be neglected.
