DIY chainsaw tire repair

In detail: do-it-yourself chainsaw tire repair from a real master for the site my.housecope.com.

A chainsaw is a very useful thing in the household. After all, with it, a lot of tasks of home construction, gardening and landscaping are quickly and relatively easily solved. Chainsaws are a rather capricious tool, but with proper handling it is an indispensable assistant. Which has one weak point: the guide rail. It accounts for most of the operational loads. And this means that knowing why tires fail more often than other parts of chainsaws and how to replace them correctly if necessary will help you save money and time more than once during seasonal or project work with a tool.

3 Replacing the chainsaw tire and its fastening elements
4 Do-it-yourself chainsaw tire and chainsaw replacement, video

The tire and its fastening elements are consumable parts. The wear of this unit occurs both under workloads and as a result of improper operation. You will immediately determine the presence of malfunctions in this area. The tire will not be able to provide normal tension, lubrication and smooth running of the chain, and its fastening will not be able to fix the cutting axis relative to the tool body.

It is not safe to operate a saw with a broken bar. Therefore, at the first sign of a breakdown of the unit, you need to turn off the engine and find out what's wrong. Knowing the design features of the tire and its mounting on your chainsaw will help to successfully eliminate the cause of the malfunction.

The bar determines the axis and length of the cut by guiding the chain. But the basis of the mechanism is still fastening. It is installed in the groove between the inner plate on the motor housing and the outer plate located on the casing of the chain set. The tire and casing are fixed with a bolted connection. This part of the mount is called the “engine assembly”, and its shape and design depend on the chainsaw model. The tire mounting and the drive sprocket are closed with a separate cover.

Video (click to play).

Chainsaw bar studs

The saw chain drive links are mounted in a guide groove on the edge of the bar and are engaged with a drive sprocket connected to the power take-off shaft. When the fixing bolts are loosened, the tire can move. The chain tension can be adjusted manually or, like on professional chainsaws, automatically. Finally, a stop is located in front of the tire mount. It serves to securely fix the cutting axis when the moving chain contacts the tree.

Execution of the chainsaw drive sprocket: with a replaceable and stationary crown

A serviceable tire should provide normal chain tension. To check it, you need to release the chain brake and pull the chain by hand in the direction of its movement. If the chain does not move, then the fastener is too tight. It must be slightly released, and then again check the free play of the chain.

Adjusting the chain tension with a key

The main parts of the tire are the body and the groove. The width of the latter is called the gap. The front part of the saw bars is made of high-strength steel. The tire body is also hardened.

Currently, there are various types of saw bars on sale, which differ in:

body length and width;
gap size;
the presence of a nozzle of increased strength on the front;
the presence and type of driven sprocket hidden in the front of the tire body.

Various types of saw bars

The shape of the shank and the location of the technological holes in the tires for most amateur and professional chainsaws are standard, but structurally they can be divided into open and closed. It is obvious that the first ones are inferior to the second ones in terms of reliability of fastening to the case; the tire casing and the bolted connection are subjected to increased loads. You also need to monitor the integrity of the sprocket teeth - if it becomes dull or chipped, it will quickly render the leading links of the chain unusable.

The chainsaw tire needs regular maintenance. After each session of work, its grooves must be cleaned of dirt and sawdust, otherwise the lubricant will not flow to the chain. The wear of the groove of the tire should be even, so it should be turned over from time to time. In addition, before starting work, always check the presence of oil on the body of the chain and in the gap.

Checking the operation of the lubrication system

More than three chain sets with one bar are not recommended. During operation, the gap, despite all the strength of the metal of the tire body, expands, which leads to the appearance of play when the chain moves and its sagging even at the extreme forward position of the tire.

The driven sprocket located at the front of the tire is lubricated separately. Oil does not get there, unlike the rest of the guide groove. It is poured into special holes in the front of the tire, and if there is no asterisk, it is applied to the toe of the tire.

Separate nose sprocket lubrication system

To replace the fastening elements, the bar and the chain set, it is necessary to disassemble the entire fastening mechanism. It does not hurt to prepare a rectangular piece of cloth or cardboard in advance, as well as free space on the table for disassembling the tool and temporarily placing the removed parts.

Chainsaw tire mounting scheme

Replacing the fasteners and chainsaw tires is necessary when:

Critical wear of the landing groove or shank elements.
Casing damage.
Violation of the fastening bolts.
Damage or deformation of the tire body.
Abrasion or breakage of the teeth of the drive and driven sprocket.
Damage to the grooves for supplying lubrication to the chain.
Worn chain tensioner.
Wear of the mounting groove and tire retainer.

That's why the guide bar and fasteners are consumable parts - you only need one universal key, supplied with the tool, to replace them. And, of course, knowledge of the algorithm for disassembling, assembling and adjusting the mechanism.

Chainsaw with tire removed

To disassemble the tire mount:

put the engine vertically and, having unscrewed the corresponding nuts, remove the cover of the drive sprocket;
lift the bar by the front end and turn the chain clamping screw, releasing it from the groove of the bar;
pull the chain from below and, turning the clamping screw, release it from the groove;
remove the chain from the drive sprocket and pull it out from under the casing, then set it aside;
in the presence of damage or signs of wear, the casing and fastening gaskets should be replaced;
remove the chain bar to be repaired or replaced from the groove.

After that, the chain must be put on a new tire and install the latter in the groove being installed. Next, the headset is engaged with the drive sprocket and closed with a lid. Just before starting work, do not forget to check the absence of slack in the chain and the quality of its tension.

If the fastening of the new tire and the installation of the headset are done correctly, the chainsaw is ready to work again. By the way, just in case, you should make sure of this by sawing a few thin branches.

A chainsaw is a very useful thing in the household. After all, with it, a lot of tasks of home construction, gardening and landscaping are quickly and relatively easily solved. Chainsaws are a rather capricious tool, but with proper handling it is an indispensable assistant.Which has one weak point: the guide rail. It accounts for most of the operational loads. And this means that knowing why tires fail more often than other parts of chainsaws and how to replace them correctly if necessary will help you save money and time more than once during seasonal or project work with a tool.

Chainsaw bar studs

Execution of the chainsaw drive sprocket: with a replaceable and stationary crown

With all the desire, a chainsaw cannot be attributed to complex devices. Moreover, the simplicity of the design is its hallmark. But repairing a chainsaw can still be time consuming. The difficulty lies not directly in repairing a chainsaw with your own hands, but in accurately diagnosing a malfunction. One sign of inoperability can be caused by many reasons. Therefore, before disassembling the engine or carburetor, it is necessary to analyze the symptoms of a malfunction well. No instructions for repairing a chainsaw on your own can replace simple logic.

A chainsaw is a tool that cuts wood with a closed chain and is equipped with a two-stroke gasoline internal combustion engine. The ability of a chainsaw to work continuously for a certain time is the main distinguishing ability, which should be paid attention to.

The main structural units of a chainsaw are: a chainsaw tire, a chain and a gasoline engine that drives the chain and tire. By scope and functionality, chainsaws are divided into the following categories: professional, semi-professional and household amateur.

Amateur chainsaws are used mainly in everyday life, for gardening in the countryside or at their summer cottage. Such saws are very light in weight (3-4 kilograms without a chain and bar), compared to their older brothers, their vibration is very low, which makes working with this device quite comfortable.Household chainsaws are primarily designed for a short period of use (about 5 hours a week), the motor power is small, but these shortcomings are compensated by ease of operation. With the help of household chainsaws, summer residents most often do a little work - harvesting, firewood, cutting garden trees and pruning branches.

With a semi-professional chainsaw, you can easily perform a wider range of work - from repairs on your site to logging. The time of continuous operation of such a saw is 2-3 hours per day. The power of the gasoline engine in semi-professional devices has been increased. It is possible to achieve maximum productivity, to carry out a blockage of trees with medium and small trunk diameters. Often, semi-professional chain saws are used to cut knots. The only difference between such devices and professional ones is that they cannot be used continuously throughout the working day.

Professional chainsaws are mainly used in logging and industry. The engine power of professional chainsaws is designed for sawing trees of any size and diameter. Such chainsaws are made of wear-resistant material and have a particularly strong chain, which allows you to work continuously for 8-16 hours.

All breakdowns of chainsaws are conditionally divided into two groups: malfunctions of the engine with all its systems and components (fuel supply system, ignition, exhaust system, cylinder-piston group) and malfunctions of other components (lubrication system, clutch, tire, chain brake).

Violations in the functioning of chainsaw engines occur quite often, it is their correction and detection that takes users the most time. They boil down mainly to such manifestations: the engine does not start, the engine starts, but stalls or is completely unstable, the engine does not develop power, that is, it works normally at idle, but stalls under load.

When repairing a Stihl chainsaw with your own hands, it is necessary to act by elimination method - check all possible causes of failure one by one, starting with those whose diagnosis and elimination will take you less time.

Almost all types of engine problems that were listed above can be caused by ignition system failures. When they occur, it is recommended to start troubleshooting with a candle. This is justified by the fact that its condition will also provide useful information about the functioning of the fuel system. If a problem occurs, remove the spark plug and inspect it.

When the candle is dry, then most likely the problem is not in the ignition system, but in the fuel mixture not getting into the cylinder. You can wrap the candle back and take on the fuel system. When the spark plug is splattered with the fuel mixture, there is an overabundance of it. This can be caused by misalignment of the carburetor or a violation of the rules for starting. The candle must be wiped and dried, draining the cylinder, then shut off the fuel supply and operate the starter to remove excess fuel. After that, replace the candle and repeat the start.

Maybe in your case the ratio between gasoline and oil in the mixture is violated, the carburetor is not adjusted, or low-quality oil is used. Rinse the candle in gasoline, remove carbon deposits with a needle or awl, clean the electrodes with a fine sandpaper and reinstall. Even when repairing a goodluck chainsaw with your own hands, which consists in checking the candle, there is good reason to believe that the malfunctions are in the fuel system, it is necessary to check the candle for a spark.

If there is no spark, simply replace the spark plug. The reasons for the lack of a spark can also be hidden in a failed ignition module or violations of the gap between the flywheel magnetic circuit and it. The distance should be 0.2 mm.Violation of the gap becomes especially likely if before that you disassembled the saw with the removal of the ignition module and flywheel. The gap must be set using a gasket, which has a thickness of 0.2 mm, placed between the ignition module and the flywheel boss. A defective ignition module must be replaced.

If it has been determined by inspection of the spark plug that no fuel is being delivered to the cylinder, all the reasons for this must be considered. In particular: not flowing from the fuel tank due to the fact that the hole in its cover is clogged, while a vacuum is created in the tank, which prevents the fuel from flowing out; insufficient flow or non-flow of fuel from the carburetor into the cylinder; contamination of the fuel filter, which is installed in the tank.

Insufficient fuel supply or the lack of the correct ratio between air and fuel, which are mixed in the carburetor, occurs due to the following reasons: due to an unadjusted carburetor, clogged air filter, clogged filter screen or carburetor passages.

Repair of a chainsaw, as a rule, is not complete without cleaning the air filter, as it gets dirty quickly enough. When this happens, air intake into the carburetor is reduced, the fuel mixture is too rich at the outlet, and this in turn disrupts the normal functioning of the engine. The dirty filter must be removed for cleaning very carefully so that dirt does not get into the carburetor from it. Clean the filter or wash in water and detergent, dry and reinstall.

Eliminate misalignment of the carburetor by adjusting it. This can be done with three screws - minimum and maximum speed. Carry out the adjustment in the strictest accordance with the chainsaw repair instructions, failure to comply with which often leads to engine failure. Some chainsaw manufacturers leave one adjusting screw to prevent unwanted interference by inexperienced users in the functioning of the carburetor.

If the carburetor adjustment did not help, it is recommended to clean the filter mesh and channels, and also check the membrane for integrity. The carburetor is one of the most complex chainsaw devices, therefore, it is necessary to start disassembling and cleaning it with an understanding of the responsibility of this operation. This unit consists of a large number of small parts that have an unpleasant feature of jumping out unnoticed from their places and getting lost forever, so that after disassembling this capricious device, it may not be possible to assemble it.

The cause of the engine malfunction, especially if it functions normally at low speeds and stalls under load, is the clogging of the muffler spark arrester with combustion products, which prevents normal exhaust. In this case, do-it-yourself repair of a Husqvarna chainsaw consists in removing the muffler, if it is collapsible, then disassembling it, and wet cleaning the unit from carbon deposits using a detergent.

After washing, dry the non-separable muffler with a hairdryer. Remember that soot contains substances that are carcinogenic, and dry cleaning, after which they can be inhaled, is unacceptable. When removing the muffler, plug the engine outlet with a clean rag.

The muffler can become clogged due to the following reasons: due to the use of a fuel mixture with a large amount of oil (oil level recommended by manufacturers), the use of low-quality oil or oil that is not intended for two-stroke engines.

The most serious are the breakdowns of the cylinder-piston group of the chainsaw. This is the wear of the piston and cylinder, scuffing and scratches on their surface, sinking in the grooves of the piston ring and their wear, as well as wear of the crankshaft bearings.In the usual manner, these malfunctions provoke a drop in the pressure level in the cylinder and the inability to start the engine in the future, or its inability to give full power.

There are several ways to help assess the condition of the cylinder-piston group. Remove the muffler and look through the window, in which part of the side surface of the unit is visible. Despite the limited overview, it is possible to get a general idea of the CPG.
Turn the crankshaft using a flexible shaft electric motor or a starter manually, while monitoring the pressure on the pressure gauge.

For a working chainsaw, the last indicator should be in the range of 0.8-0.9 MPa. With its fall, the power of the engine also decreases. At a pressure level of 5 atm, the engine can and will work, but at idle.It will be possible to accurately assess the state of the CPG only after repairing the ground saw with your own hands, which consists in disassembling the engine - disconnecting the crankcase from the cylinder and removing the piston. If there are scuffs, deep scratches or chips on the last one, it must be changed. If the surface of the cylinder is damaged or worn out, there is a chance to bore it to the repair size. The causes of low compression are coking and wear of the piston ring. Serviceable rings are always clean from carbon deposits, sit freely in the piston groove and are pressed tightly against its inner surface.Rare do-it-yourself Ural chainsaw repair manuals do without mentioning breakdowns in the chain lubrication system, which are quite common. They usually manifest themselves as insufficient or no lubrication of the chain and the formation of oil smudges. If the chain is dry, first of all, it is necessary to inspect the channels through which oil is supplied to the tire and clean them. Their blockage is not uncommon. Image - Do-it-yourself chainsaw tire repair

In case of significant oil leakage (a small level of leakage is considered normal), it is recommended to check the tightness of the connection to the pump fittings of the tubes. They may crack or fall off. In addition to smudges, a violation of the tightness of the oil line can also provoke insufficient chain lubrication. The pump will suck in air, which will necessarily affect its performance. It is customary to eliminate such violations by sealing the tubes with sealant or replacing them. The most serious malfunction of the lubrication system are cracks that form in the oil pump housing. It must be replaced in this case.

Some chainsaw parts that are subject to natural wear must be replaced after a certain useful life. Their breakdown is a regularity and not at all a malfunction. Wear parts include a tire, a chain, a drive sprocket, anti-vibration system units, and others.

If you do not repair the husqvarna chainsaw with your own hands and replace the wear parts in time, then their excessive wear will affect other parts of the chainsaw in the most negative way. In particular, if the drive sprocket and tire are not changed in time, then the increased vibration will badly affect the crankshaft bearings. The limit of the depth of development of the teeth of the sprocket should reach 0.5 millimeters.

Although sprockets in practice often operate to wear 1 millimeter or more, not suspecting that this causes an increase in loads on the crankshaft bearings, their accelerated failure. When three or four chains are worn out, it is necessary to change the tire directly if its wear by this time reaches the limit value.

The chainsaw bar wears particularly hard in the areas where cutting occurs most often, usually on the underside of the guide bar. For any chain replacement, the bar must be rotated 180 degrees relative to the horizontal axis for even wear.

Now you know that you can troubleshoot the chainsaw with your own hands.To do this, always have a chainsaw repair manual at hand. And in order to finally understand this difficult matter, we suggest that you watch a video about chainsaw repair, which will help consolidate all the acquired knowledge in practice.

Do-it-yourself chainsaw repair

All chainsaw malfunctions can be divided into two main groups: engine problems 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.).

the engine does not start;
starts, but stalls;
works unstable;
does not develop power, i.e. Runs fine at idle, but stalls under load.

When repairing a chainsaw with your own hands, it is necessary to act as an exception - to alternately inspect all possible causes of a malfunction, starting with those that take the least time to check and eliminate (see here about the device and operation of a two-stroke motor).

Ignition system. Almost all types of engine problems listed above can be caused by ignition system failures. Therefore, when they occur, it makes sense to start troubleshooting with a candle. This is all the more justified since the state of the latter can provide useful information about the operation of the fuel system. So, if a problem occurs, you need to unscrew the candle and inspect it.

The wire is disconnected, and the candle is unscrewed with a special key.

If the spark plug is dry, it means that the problem is most likely not in the ignition system, but in not entering the cylinder fuel mixture. You can wrap the candle back and take on the fuel system. If the spark plug is heavily splattered with the fuel mixture, then there is an excess of it. This may be due to misalignment of the carburetor or a violation of the rules for starting. The candle is wiped and dried, the cylinder is drained by cutting off the fuel supply and working with the starter - to ventilate the combustion chamber and remove excess fuel. Then install the candle in place and repeat the start.

The presence of a large amount of black soot also indicates malfunctions in the fuel system.

The ratio between oil and gasoline in the mixture may be violated, the carburetor is not adjusted, or low-quality oil is used. The candle is washed in gasoline, cleaned with a needle or awl from soot, the electrodes are cleaned with fine sandpaper and put in place.

In all these cases, it will not be superfluous to check the gap between the spark plug electrodes. Depending on its brand, it should be in the range of 0.5-0.65 mm. You also need to check the sealing gasket of the spark plug. 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 a spark plug test, there is good reason to believe that the malfunction is in the fuel system, you need to check the spark plug for a spark. At least to be sure that everything is in order with this. For this:

put the ignition cable on the spark plug;
using pliers with insulated handles, apply the thread or nut of the candle to the cylinder;
pull the starter handle and see if there is a spark or not.

If there is no spark, just replace the spark plug. If the new candle does not have a spark, you need to check the condition of the high-voltage wire for a break and contact with the candle.

The reason for the lack of a spark may 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 the saw was disassembled with the removal of the flywheel and the ignition module before that. The gap is set using a 0.2 mm thick gasket placed between the flywheel boss and the ignition module.A defective ignition module must be replaced.

After checking the ignition system in this way and not finding a malfunction, you can proceed to the supply system fuel mixture.

Fuel supply system. If by inspection of the spark plug it was found that fuel was not entering the cylinder, all possible reasons for this should be considered. It could be:

non-flow of fuel from the tank due to a clogged hole in its cover (breather), while a vacuum is created in the tank that prevents fuel from flowing out;
contamination of the fuel filter installed in the tank;
no intake or insufficient intake 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 with a full jet, the breather and filter can not be checked, if it does not flow or flows weakly, we can assume that the cause of the malfunction has been 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 the 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.