How to remove a sprocket from a Husqvarna 136 chainsaw

Table of Contents:

The leading sprocket of the chainsaw. Correct selection and replacement

remove, sprocket, husqvarna, chainsaw

The chain transmission of a chainsaw of any design determines the performance of the tool. over, during operation, the chain stretches, and the teeth of the drive sprocket wear out. An illiterate sprocket selection will dramatically reduce the durability of the chainsaw teeth, and its incorrect adjustment will lead to premature wear.

Design features of the leading sprockets

Any manufacturer specifies the pitch of the teeth in the instruction manual. Considering that a driven sprocket is also installed on the saw bar (designed to create the necessary tension), the step there and there should be the same.

Chainsaw drive sprockets can be solid and prefabricated. In the first case, the sprocket includes a hub onto which a ring gear is pressed. This is how the parts in Champion chainsaws are arranged. The product should be removed completely when replacing, since at home it is almost impossible to comply with the preload value set at the manufacturing plant. And buying a crown separately is also a problem.

In chainsaws from Stihl or Husqvarna, the replaceable crown is located directly on the drum shaft, and therefore its replacement is not difficult.

Tooth wear is established according to the following criteria:

  • There are clearly visible radii in the places of transition from tooth to cavity.
  • Tooth width uneven in height.
  • Chipped metal at the top of the tooth.
  • On the inner surface of the bore in the hub, there are numerous seizures and risks (due to poor lubrication).
  • A groove from the saw bar is visible on the sprocket (it is also necessary to change the chain).
  • The chain is seized at the initial moment of start.

If at least one of the above factors is present, the drive sprocket must be replaced.

Before starting work (especially if the chainsaw has worked relatively little), it is worth checking the fastening of the saw bar. The tensioning screw has come off or the fastening nuts have been unscrewed. the guide is already misaligned with the longitudinal mowing line of the saw blade. It begins to contact not with the center, but with the periphery of the drive sprocket teeth, provoking their intense wear. After tightening the indicated elements, the operation of the chainsaw is checked: if the backlash is not eliminated, then the asterisk will have to be changed.

A little about the rules for operating the node

Regardless of the manufacturer’s brand (Stihl, Husqvarna, Partner, Patriot, Makita), chainsaws are divided into household, semi-professional and professional. The difference, however, is not in the quality of the assembly or the manufacture of the components, but in the class of tasks performed, the performance and the continuous power of the drive. This predetermines the choice of the material of the leading sprocket for the chainsaw, its design and the design of the saw chain.

The performance of the tool will be determined by the way the chain-sprocket pair is operated. In most cases, users use one of two options:

  • The chain is operated until the teeth are completely worn out, and then both the saw blade and the sprocket are replaced at the same time;
  • Periodic replacement of chains with different pitch, and each will require its own drive sprocket.

The choice of option is often determined by the owner’s attitude to his instrument. If it doesn’t matter what to cut (wood or steel staples stuck in it, screws, etc.), then you can stop at the first option. The chain, however, will have to be adjusted periodically, thereby reducing the performance of the chainsaw.

It is strongly not recommended to leave the old chain with a new sprocket and vice versa. When the saw blade is worn out, the probability that the tooth pitch will not match is almost one hundred percent. Therefore, at the initial moment of starting, both components of the chain drive will be subjected to significant dynamic loads. As a result, either the chain will stretch prematurely, “adjusting” to the sprocket, or upon impact, one of the teeth on the drive sprocket will burst.

In addition, it is worth focusing on the operation of the bearing assembly of the drive sprocket shaft. When the saw is operating at working speed, only the crankshaft rotates. But all chainsaws periodically operate at idle speed when the bearing rotates. With a lack of lubrication, the wear of the seat occurs, and. as a result. additional beating of the teeth of the still fully functional chain transmission.

It follows from this that when replacing the chain and the drive sprocket for a chainsaw, it is a good idea to replace the bearing at the same time.

How to remove a drive sprocket from a chainsaw?

As already noted, the sprocket can have a split and pressed-on crown. Therefore, the sequence of actions will be different.

For a stationary positioned crown, the following are sequentially produced:

  • Dismantling the casing;
  • Removing the bar along with the chain;
  • Disconnecting the clutch from the engine (you must first lock the piston);
  • Removing the clutch together with the drum;
  • Removing the crown from the drum using a conventional open-end wrench (some manufacturers also attach a puller to the spare parts kit).

The assembly is carried out in the reverse order. For some models, before dismantling the crown, you will also have to remove the air filter.

When disassembling the drive sprocket for a chainsaw, which has a replaceable crown, the order of work will be almost the same, but at the final stage only the crown needs to be replaced.

After completion of work, it is necessary to check the effectiveness of the replacement. To do this, check the chain tension: if, when the brake is released and you try to pull the chain in the direction of its movement, it is motionless, then the fastener is “overtightened”, and the tensioner should be slightly released.

The success of the work is determined by the availability of a special repair kit purchased for a specific brand of chainsaw. Otherwise, you should know exactly the size of the saw and the pitch of the teeth.

Algorithm for replacing the clutch drum

Chainsaw clutch closes the sprocket.

First of all, it should be noted that when buying spare parts for a chainsaw, you need to strictly observe the type of drum or use the advice of a specialist when it comes to modernizing it. As a rule, when changing the drum and saw chain at the same time, the drum bearings are also replaced.

Here you should purchase a special repair kit, which provides for the presence of both a drive sprocket and a bearing. Then you should prepare the tool and parts that will be required for the work:

  • universal wrench sold with chainsaw
  • mechanism piston stopper (plastic or metal in standard versions)
  • puller of the centrifugal mechanism or clutch (selected depending on the model of the chainsaw).

During the operation, the following actions are performed:

Chainsaw sprocket location diagram.

  • First, the saw headset is removed, the tire cover nuts are unscrewed with a universal wrench. The cover is removed, the bar and chain are removed.
  • After that, the air filter is removed.
  • The saw candle is unscrewed with the universal wrench. Instead, a prepared piston stopper is inserted, which will allow fixing the position of the piston in the cylinder.
  • The clutch remover fits into the universal key socket. Then, using the resulting device, the clutch is unscrewed. All actions must be carried out clockwise.
  • The clutch is removed, freeing access to the internal parts. Now you can remove the sprocket (clutch drum).
  • Depending on the type of drum, it is inspected or the crown is checked. The asterisk or crown is replaced with new ones. When installing new parts, the condition of the clutch separator must be carefully checked. Particular attention must be paid here to the springs of the centrifugal mechanism and the cams. If severe wear is detected, these parts also need to be replaced.
  • If the condition of the parts does not cause any complaints, all parts of the chainsaw are assembled in reverse order. First of all, the piston stopper is unscrewed, the starter cord is pulled out, then the stopper is screwed in again. Such complex actions allow you to clamp the centrifugal mechanism of the chainsaw on the crankshaft.
  • Using a standard universal key, the clutch is clamped counterclockwise, that is, against the rotation of the chain.
  • After that, all nodes and parts can be successfully screwed into their original places.
READ  How to Lubricate a Husqvarna Flexible Trimmer Shaft

In order to replace the sprocket on a chainsaw, all work must be done carefully and carefully.

Without special tools, repair work may end in failure: not only the star or centrifugal mechanism may break, but also the saw chain.

Troubleshooting

Whatever one may say, but breakdowns still occur. But it is important not just to repair the device, but to determine the root cause.

The most common problems:

  • Oil leaks due to a violation of the integrity of the oil hose or its sealing at the attachment points.
  • Oil does not flow to the chain due to clogged feed channels with dust and chips.
  • The engine does not start or starts and immediately stalls due to an unregulated / malfunctioning carburetor, clogged sopun, air filter, muffler.
  • Chain wedges due to drive sprocket defects.
  • Engine clogged due to carburetor malfunction and high fuel supply.

Replacing an asterisk on a chainsaw with your own hands

In the process of regular operation of the chainsaw, the sprocket shown in the photo experiences heavy loads, and therefore it often fails. The sprocket, or otherwise the clutch drum, is an important and integral part of the chainsaw, which transfers the rotational energy from the drive to the chain.

Considering the safety of the drive sprocket and chainsaw chain, there are two ways to operate:

  • using only one chain
  • using two or more chains alternately.

In the first case, the chain can be operated until it is completely erased. However, there are a number of inconveniences here. Using only one chain, it is problematic to monitor its condition during intensive work. Hitting nails or other metal parts makes it necessary to adjust the chain, but since it is alone, the work is slowed down.

In the second case, the alternation of the chains allows uniform wear of both the sprocket and the chains.

In addition to the wear of the sprocket itself, do not forget about its bearing, which operates in idle mode. Therefore, very often they do not pay attention to it and forget to lubricate.

Usually, when replacing a drive sprocket, they immediately try to replace both the bearing and the chain. This is done due to the change in the length of the chain pitch as a result of intensive work.

Features of the clutch drum in chainsaws

The drum located at the base of the clutch of the mechanism is an integral part of the chain drive system. This detail resembles a star in its shape, due to which it got its name. Depending on the type of chainsaw, the part can be professional or household. Since a professional saw is used more often than a household saw, the drive sprocket also needs to be replaced regularly. If we talk about household tools, then everything here depends on the amount of work performed and the load that is on the circuit of the device.

Most often, the sprocket, ring and saw bearing need to be replaced.

In any case, the main reason for replacing a sprocket is chain wear on its teeth. In the event that a monolithic drum is installed in the device, the surface of the chain cuts it almost completely, which requires a complete replacement of the entire part. If the chainsaw has a drum with a replaceable crown, here you can limit yourself only to replacing the crown.

Usually, in order to remove the sprocket from the chainsaw, many people turn to specialized service centers, but if there is a need to save the family budget, you can do this work yourself. This activity does not look complicated, but it requires you to have all the necessary parts and tools. The sprocket replacement process is the same for any device model.

Chainsaw Husqvarna 137. Replacing the clutch drum

The clutch drum of a chainsaw is one of the most common consumables in a chainsaw, because it is he who drives the cutting chain. The drums themselves are divided into two types. with a welded drive sprocket and with a replaceable rim, and in the second case only the replaceable rim wears out, the drum itself changes much less often.

Husqvarna Chainsaw Repair. Replacing the Clutch Drum (Husqvarna Part # 537291602)

When repairing the clutch of a chainsaw, they adhere to the rule. when two chains are completely worn out, the tire changes, when two tires are worn out, the clutch drum changes. The level of wear of the sprocket can be determined without special devices, it is enough to simply inspect it. the chain, moving at high speeds, over time wipes the teeth along which it moves. If the wear is strong enough, then replacing the chainsaw clutch drum is inevitable.

The article will focus on the Husqvarna 137 chainsaw. Replacing the clutch drum is a simple procedure and takes place in several stages.

  • First you need to remove the tire and chain brake cover. For this, the combination key that comes with the chainsaw is suitable.
    Then remove the air filter cover, unscrew the spark plug, and lock the piston of the Husqvarna 137 chainsaw. For this procedure, it is recommended to use a regular rope, since when using a metal stopper there is a risk of puncturing the piston.

How to remove an asterisk from a chainsaw: self-replacement

Today, almost every resident of a country house or summer resident has his own chainsaw. You cannot do without it during regular logging, gardening and municipal work. The demand for chainsaws does not fall, but even grows due to the fact that these devices do not require much knowledge and skills to work. The only thing that needs to be done regularly is to carry out technical inspections.

As with any tool, chainsaws require careful personal care. It is necessary to constantly check the oil supply to the chain, chain tension, brake operation, ignition system and other things. Fortunately, almost any malfunction can be solved at home on your own.

Recommendations: how to remove an asterisk from a chainsaw

  • Features of the clutch drum in chainsaws
  • Algorithm for replacing the clutch drum

Many tools require regular replacement of consumable parts. This also applies to drinking. That is why the question of how to remove an asterisk from a chainsaw, which is also often called a clutch disc or centrifugal mechanism, is very relevant for home craftsmen. In this regard, it is necessary to consider what is called an asterisk and why it is needed.

The clutch drum, called a sprocket, is an integral part of your chainsaw.

Replacing an asterisk on a chainsaw with your own hands

In the process of regular operation of the chainsaw, the sprocket shown in the photo experiences heavy loads, and therefore it often fails. The sprocket, or otherwise the clutch drum, is an important and integral part of the chainsaw, which transfers the rotational energy from the drive to the chain.

Considering the safety of the drive sprocket and chainsaw chain, there are two ways to operate:

  • using only one chain;
  • using two or more chains alternately.

In the first case, the chain can be operated until it is completely erased. However, there are a number of inconveniences here. Using only one chain, it is problematic to monitor its condition during intensive work. Hitting nails or other metal parts makes it necessary to adjust the chain, but since it is alone, the work is slowed down.

In the second case, the alternation of the chains allows uniform wear of both the sprocket and the chains.

In addition to the wear of the sprocket itself, do not forget about its bearing, which operates in idle mode. Therefore, very often they do not pay attention to it and forget to lubricate.

Usually, when replacing a drive sprocket, they immediately try to replace both the bearing and the chain. This is done due to the change in the length of the chain pitch as a result of intensive work.

How to remove an asterisk from a chainsaw: self-replacement

Today, almost every resident of a country house or summer resident has his own chainsaw. You cannot do without it during regular logging, gardening and municipal work. The demand for chainsaws does not fall, but even grows due to the fact that these devices do not require much knowledge and skills to work. The only thing that needs to be done regularly is to carry out technical inspections.

As with any tool, chainsaws require careful personal care. It is necessary to constantly check the oil supply to the chain, chain tension, brake operation, ignition system and other things. Fortunately, almost any malfunction can be solved at home on your own.

READ  How to change the rope on a chainsaw starter

Troubleshooting

Whatever one may say, but breakdowns still occur. But it is important not just to repair the device, but to determine the root cause.

The most common problems:

  • Oil leaks due to a violation of the integrity of the oil hose or its sealing at the attachment points.
  • Oil does not flow to the chain due to clogged feed channels with dust and chips.
  • The engine does not start or starts and immediately stalls due to an unregulated / malfunctioning carburetor, clogged sopun, air filter, muffler.
  • Chain wedges due to drive sprocket defects.
  • Engine clogged due to carburetor malfunction and high fuel supply.

The procedure to change the asterisk on a chainsaw with your own hands

There are many videos on the Internet that clearly demonstrate how to replace the clutch drum (sprocket) of such famous brands as Stihl, Husqvarna, Druzhba, Ural and others. It’s easy to find them.

Each type of chainsaws has its own design features, but their principle of operation is the same, so the general idea is reduced to the following actions:

  • The chain brake cover is removed. In this case, the brake should be pulled towards you so that the brake band does not come into contact with the clutch cup. Next, a couple of nuts holding the cover are loosened. The chain tension is released allowing the cover to be removed completely.
  • The tire is removed with a chain, along the way, any dirt is removed.
  • Now you need to fix the piston in the cylinder. This is done using a special stopper and retainer, but you can use a regular rope. By rotating the clutch, it is necessary to detect the moment when the piston reaches the outlet. The rope is lowered into the spark plug hole and fixes the piston. For convenience, several knots are tied on the rope. After replacement, the rope will need to be removed, so it should not be released.
  • After that, you can start unscrewing the clutch nut. It is important not to forget that there is a left-hand thread, that is, you need to twist it in a clockwise direction. The use of a chisel with a hammer is unacceptable. This will damage the nut.
  • The clutch and sprocket drum can now be removed.
  • Replacing the clutch drum.
  • Assembling all parts together in reverse order.

When replacing a sprocket, some features of the various saws should be taken into account. For example, a Stihl chainsaw may have a washer between the sprocket and the engine. You need to remember its position, remove and repeat the position during assembly.

Also, some chainsaw oil drives are equipped with a mustache spring to transfer rotational energy from the sprocket to the pump. If, when assembling the saw, the mustache does not fall into its groove, then the oil will stop getting on the saw chain, which can lead to sad consequences.

To avoid most breakdowns, including the drive sprocket, it is necessary to monitor the technical condition of the saw, regularly inspect, lubricate, etc. You also need to make sure that nails, concrete, stone and other obstacles that lead to early wear of parts do not meet in the path of the chain.

As for replacing the drive sprocket, here you should use information about the design features of the saw (Husqvarna, Stihl, Ural, Druzhba and others), which can be found in the instructions attached to the saw.

Design features

The leading sprocket of the chainsaw can be of two types: prefabricated or solid (stationary). The one-piece is in the form of a one-piece device, which is located directly behind the clutch. Such sprockets in the form of a clutch plate with a welded toothed sprocket are also called stationary. This type of construction is used in most chainsaws. Replacing such crowns on a chainsaw does not present any difficulties, but you only need to remove them entirely with a drum.

On expensive chainsaws, assembled type sprockets are used. The crown is put on the drum shaft, as a result of which the torque is transmitted to the chain. Replacing a prefabricated device is even easier, since the crown is removed and the drum remains in place. The prefabricated structure of the element in question is a way to extend the life of the clutch. When the drive sprocket is worn out, it needs to be replaced. If this is not done, then the tool life is significantly reduced, as a result of which the wear rate of the internal combustion engine increases.

Algorithm for self-replacement of the clutch drum with an asterisk

The technology for replacing the leading sprocket provides for the implementation of the entire amount of work in a given sequence:

  • dismantling the headset and air filter;
  • installation of a piston retainer in the spark plug hole;
  • the clutch and the gear drive, made in one piece with the drum, are removed by means of a puller, the sprocket can only be unscrewed clockwise.

If a large cage wear is detected, the springs of the centrifugal mechanism and cams are broken, it is recommended to replace the entire set.

If the condition of the removed parts is not in doubt, the entire mechanism is assembled in reverse order. To securely fix the clutch on the crankshaft, it is enough to unscrew the piston stopper, pull out the standard starter cord and return it to its original position.

Amateur craftsmen should be warned against simplifying the requirements of repair technology and saving money on installing relatively cheap Chinese components.

The quality of the work done is guaranteed by attention, accuracy, adherence to the sequence of all dismantling and assembly operations.

Oil pump and clutch replacement on Husqvarna 136 replacement

Tips: how to remove a sprocket from a chainsaw

  • Features of the clutch drum in chainsaws
  • Method for changing the clutch drum

Many tools require constant replacement of consumable parts. This also applies to drinking. That is why the question of how to remove an asterisk from a chainsaw, which is often called a clutch disc or a centrifugal mechanism, is very topical for home craftsmen. In this regard, you need to discern what is called an asterisk and for what purposes it is needed.

The clutch drum, called an asterisk, is an integral part of the chainsaw.

Replacing the drive sprocket on a chainsaw

Regardless of the class of the chainsaw and its performance characteristics, the design of the removable saw sets is almost identical. The saw set includes a guide bar made of a special alloy and a chain, which is activated by the gear rim of the drive mechanism. To extend the resource of the saw chain, timely replacement of the sprocket on the chainsaw is important.

How to remove an asterisk from a chainsaw: varieties and design features

With the constant use of a tool such as a chainsaw, it is important to regularly carry out diagnostic measures by replacing consumables and parts. One of these consumables is a sprocket or chain drive mechanism. If the question arises of how to remove the sprocket from the chainsaw correctly, then it’s time to replace it. When and how correctly the replacement of crowns on chainsaws is carried out, we will consider further.

Husqvarna 137, clutch and sprocket replacement

A fairly common problem in Husqvarna 137 and 142 chainsaws is a breakdown of the oil pump. This video shows the fast-moving.

How to remove a sprocket from a Husqvarna 137 chainsaw

The movement of the chain along the tire of the chainsaw is carried out due to the drive sprocket connected to the engine gearbox.

The wear of the spline on the sprocket indicates that it needs to be replaced as soon as possible, otherwise the clutch with the chain will not occur, and the chain itself will be damaged.

It should be borne in mind that the drive sprocket has a number of features depending on the saw model and its type. In this article, we will highlight such a question as how to remove an asterisk from a chainsaw.

Here you should receive a special repair kit, in which the presence of both a drive sprocket and a bearing is foreseen. Then you should prepare the tool and parts that will be required for the work:

  • a universal wrench sold with a chainsaw;
  • mechanism piston stopper (in standard versions, it is plastic or iron);
  • puller of the centrifugal mechanism or clutch (selected depending on the model of the chainsaw).

During the operation, the following actions are performed:

Chainsaw sprocket diagram.

  • First, the saw headset is removed, the tire cover nuts are unscrewed with a universal wrench. The cover is removed, the bar and chain are removed.
  • Then the air filter is removed.
  • The saw candle is unscrewed with the universal key. Instead, a prepared piston stopper is inserted, which will allow fixing the position of the piston in the cylinder.
  • The clutch remover fits into the universal key socket. Then, with the help of the resulting device, the clutch is turned out. All actions must be carried out clockwise.
  • The clutch is removed, freeing access to the internal parts. Now you can remove the sprocket (clutch drum).
  • Depending on the type of drum, it is inspected or the crown is checked. The asterisk or crown is changed to new ones. When installing new parts, you need to painstakingly check the condition of the clutch separator. Special attention should be paid here to the springs of the centrifugal mechanism and the cams. If severe wear is detected, these parts also need an inevitable replacement.
  • If the condition of the parts does not cause any complaints, all parts of the chainsaw are assembled in a reverse sequence. First, the piston stopper is turned out, the starter cord is stretched, then the stopper is screwed in again. Such complex actions allow you to clamp the centrifugal mechanism of the chainsaw on the crankshaft.
  • Using the universal key, the clutch is clamped counterclockwise, in other words, against the rotation of the chain.
  • After that, all nodes and parts can be successfully screwed into their original places.
READ  How to Reduce the Supply of Oil to a Chainsaw Chain

In order to change the asterisk on the chainsaw, all work must be done carefully and carefully.

Without special devices, repair work can end in failure: not only the star or the centrifugal mechanism can break, but also the saw chain.

As you can see from the information presented, the question of how to remove the asterisk from the saw can be successfully solved on your own. Once performed, the operation will allow you to perform it again and again, as the need arises, and attention and accuracy will be the key to a job well done.

The movement of the chain along the tire of the chainsaw is carried out due to the drive sprocket connected to the engine gearbox.

The wear of the spline on the sprocket indicates that it needs to be replaced as soon as possible, otherwise the clutch with the chain will not occur, and the chain itself will be damaged.

It should be borne in mind that the drive sprocket has a number of features depending on the saw model and its type. In this article, we will highlight such a question as how to remove an asterisk from a chainsaw.

Criteria for self-selection of a repair kit

The owner’s desire to equip the headset with a saw chain with a different pitch leads to the need to change the sprocket to a part with a crown of the corresponding profile. This requirement applies to the entire range of European and Chinese-made chainsaws.

The operational reliability of a European-assembled saw, when working in difficult conditions of increased loads, can significantly deteriorate if, instead of a branded part, a Chinese-made sprocket is installed.

How to determine the need to replace the crown

The sprocket is replaced immediately after the product in question wears out and cannot perform its functions. The wear of the crown can be determined by the following characteristic properties:

  • The presence of noticeable radii in the area of ‚Äč‚Äčtransition of the tooth to the cavity.
  • Metal chips at the top of the teeth.
  • Uneven tooth width.
  • Detection of scoring on the inside of the hub.
  • Grooving from the tire.
  • The chain comes off the tire.

The most important sign by which you should check for the above points is the appearance of signs of chain jamming when starting the chainsaw. Any of the above factors requires immediate replacement of the element in question. Details about the types of leading stars and their differences can be seen in the video.

Sequencing

Chainsaw sprocket, crown and bearing

The vast majority of household saws are sold under the Partner brand. In them, it is enough to simply change the asterisk even at home by purchasing a repair kit.

Since most often the sprocket in household saws is an assembly mechanism, it rotates due to the bearing. That is, by changing the sprocket, you inevitably change the bearing not to the shaft.

In professional models (such as Stihl and Husqvarna), as well as in household ones, if it is not possible to have a specialized key for removing the star at hand, use a soft cord with a diameter of 5-6 mm.

In all cases, the sequence of actions is as follows:

  • You need to open the side cover to gain access to the tire and sprocket.

  • Next, you need to remove the tire by loosening the chain.

This is what a chainsaw tire looks like.

  • After the sprocket is free, you need to unscrew the spark plug to access the engine piston.

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  • Turning the sprocket manually, bring the piston almost to the very top of the channel and fill the hole formed from the candle as tightly as possible with a soft cord, thereby blocking the movement of the piston.
  • Depending on the saw model and gearbox type, use an open-end wrench and unscrew the sprocket.

Thus, adhering to the recommendations given in the article, you can easily remove the sprocket from the chainsaw yourself.

How to remove and replace the drive sprocket on Husqvarna and Stihl chainsaws is described in detail in this

How to remove an asterisk from a chainsaw: varieties and design features

With the constant use of a tool such as a chainsaw, it is important to regularly carry out diagnostic measures by replacing consumables and parts. One of these consumables is a sprocket or chain drive mechanism. If the question arises about how to remove the sprocket from the chainsaw correctly, then it’s time to replace it. When and how correctly the replacement of crowns on chainsaws is carried out, we will consider further.

How to remove an asterisk from a Husqvarna, Partner, Stihl chainsaw with your own hands

The movement of the chain along the tire of the chainsaw is carried out due to the drive sprocket connected to the engine gearbox.

The wear of the spline on the sprocket indicates that it needs to be replaced as soon as possible, otherwise the clutch with the chain will not occur, and the chain itself will be damaged.

It should be borne in mind that the drive sprocket has a number of features depending on the saw model and its type. In this article, we will highlight such a question as how to remove an asterisk from a chainsaw.

What is a chainsaw sprocket for?

Chainsaw sprockets are parts of the clutch basket that rotate the chain. On chainsaws, a type of centrifugal drive is used, which is triggered automatically, which depends on the speed of the engine itself.

The device of the centrifugal mechanism is such that when the chainsaw is idling, the sprocket does not rotate. This is due to the fact that the elements of the clutch basket have a degree of freedom. This freedom is provided by friction linings and springs. As soon as the number of revolutions increases, the centrifugal force increases the force of the springs, as a result of which the elements with the friction linings are displaced. This transfers torque to the drum and sprocket, which in turn moves the saw chain.

This design of the clutch mechanism is due to the fact that when the chain is jammed, it slips. Thus, it is possible to prevent seizure of the internal combustion engine, as well as to avoid its premature failure. Regular use of the saw leads to the fact that the crown wears out, and it becomes necessary to replace it.

Alternative solutions

The sequence of working moments is identical for almost all known models on the domestic market for chainsaw technology. Experts advise using a branded part for replacement.

If we are talking about the modernization of this unit, the advisability of such a change should be clarified by consulting an experienced specialist.

The best option is to buy a repair kit, which also includes a replacement bearing. In addition to the key, you may need an individual clutch drum puller for each model, a metal or plastic stopper to fix the piston in a given position.

Feasibility of timely replacement of worn out parts of the chain drive

The design of its crown determines such an important parameter as the choice of the chain in step.

  • Installing a new part on a worn sprocket reduces the smoothness of its movement, accelerates wear, initiates the risks of its breakage and creating a traumatic situation.
  • There is also an increase in operating loads on the engine and the elements of the kinematics of the tool.
  • A similar process takes place when old stretched chains are installed on the tire, the diameter of which is adjusted to the size of the tire by removing some of the links.

Experts also advise against arbitrarily changing the size of the sprockets. The experiment can negatively affect the engine life and the kinematics of the tool as a whole.

Safety of sawing works of various degrees of complexity is ensured by the effective operation of the emergency stop brake and devices that block the expansion of the chain ends in case of accidental breakage. In any case. the most reliable prevention of emergency situations, maintenance of the chainsaw in good technical condition.