Is it wise to try to fix or sharpen the star?
The cost of this spare part is small, and self-repair or an attempt to restore a worn part never leads to the efficient operation of the chainsaw. It is recommended to replace the part with a new one if there are signs of wear.
How to unscrew an asterisk on a chainsaw:
Method for a star with a collapsible clutch drum
Do not forget that the installation of a new chain on the tire of the chainsaw. One reason is to re-equip the dust with a new asterisk. Otherwise, the chain will stretch ahead of time or break during operation. Less wear on the clutch drum gives the alternating use of several chains and periodic maintenance of its bearing. This mechanism is used exclusively at idle: when the speed rises, it is not involved in work. Experts recommend changing it along with the chain and sprocket and systematically lubricating it with chain oil.
The main signs that the asterisk needs to be changed:
- The chain has been replaced twice on your chainsaw (one of the current rules for operating a chainsaw and a saw. With frequent and active use of the tool, after two chain changes, the drive sprocket should be replaced)
- The quality of sawing has worsened, the chain needs to be tightened more often;
- You have installed a new chain, which does not fit the old drive sprocket (this part is not universal, and also has its own pitch, in addition, the steps of the drive and driven chain sprockets must match, otherwise the tool will not work)
- You are using a different bus, shorter or longer.
About replacing an asterisk on a chainsaw:
Replacing a worn chain saw sprocket. Expert advice: How to remove a sprocket from a chainsaw?
The chainsaw requires regular diagnostics and periodic replacement of worn parts. With regular use, not only the saw headset, but also the drive sprocket, becomes unusable. In this tool, it acts as a clutch disc, which is why it has a significant load both during start-up and during operation. The asterisk on the chainsaw has a simple design, so repairs and maintenance are easy to do with your own hands. In this article, we will look at how to determine the degree of wear of this part and carry out a planned replacement.
How to reduce wear on the drive sprocket?
The service life of the chainsaw clutch can be increased by routine maintenance and high-quality tool maintenance. Helpful hints:
- Lubricates the needle bearing after each sprocket change;
- Correctly select all parts of the saw headset, depending on the chain pitch, use reliable consumables;
- DO NOT replace the clutch and saw parts at the same time. This leads to a change in pitch, wear of the headset;
- Cleans dust regularly by removing the side cover.
Chainsaw sprocket replacement. A planned procedure that ensures reliable and stable operation of the tool. When diagnosing or repairing the coupling mechanism, one should take into account the design features of the model, the manufacturer’s requirements. To avoid frequent breakdowns, it is recommended to use only original parts or high-quality analogs, systematically cleans the chainsaw.
Replacing the sprocket on a Husqvarna chainsaw
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)
- Centrifugal mechanism or clutch puller (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 key. Instead, a prepared piston stopper is inserted, which allows you to fix 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 mechanisms and cams. If severe wear is detected, these parts also need to be replaced.
- If the condition often causes criticism, all parts of the chainsaw are assembled in reverse order. First of all, the piston stopper is unscrewed, the 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.
In order to replace the sprocket on the chainsaw, all work must be done carefully and carefully.
Without special tools, repairs can fail: not only the star or centrifugal mechanism, but also the saw chain can break.
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 a replaceable crown, and in the second case only the replaceable crown wears out, the drum itself changes much less often.
When repairing a chainsaw clutch, 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 wear level of the sprocket can be determined without special tools, 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 cover and the chain brake. For this, the combination wrench included in the chainsaw is suitable.
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Then remove the air filter cover, unscrew the spark plug, stopper piston of the Husqvarna 137 chainsaw. For this procedure, it is recommended to use a regular rope, as when using a metal stopper there is a risk of puncturing the piston.
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 it all 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 prerequisite for changing the sprocket is the wear of its teeth by the chain. 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 asterisk 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 all the necessary parts and tools. The sprocket replacement process is the same for any device model.
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 is NOT falling, but even growing 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 systems and other things. Fortunately, almost any malfunction can be solved at home on your own.
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 is under heavy loads, and therefore it often fails. An asterisk, or otherwise a clutch drum. It is an important and integral part of the chainsaw that transfers the rotational energy from the drive to the chain.
Considering the safety of the drive sprocket and the 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 disadvantages here. Using only one chain is problematic. Monitor its condition during intensive work. Hitting nails or other metal parts makes it necessary to reign the chain, but since it is alone, the work is inhibited.
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 works in idle mode. Therefore, very often they DO NOT pay attention to it and forget to Lubricate.
Usually, when replacing the drive sprocket, they immediately try to replace both the bearing and the chain. This is done due to the change in the chain pitch length as a result of intensive work.
The main signs that the asterisk needs to be changed:
- The chain has been replaced twice on your chainsaw (one of the current rules for operating a chainsaw and a saw. With frequent and active use of the tool, after two chain changes, the drive sprocket should be replaced)
- The quality of sawing has worsened, the chain needs to be tightened more often;
- You have installed a new chain, which does not fit the old drive sprocket (this part is not universal, and also has its own pitch, in addition, the steps of the drive and driven chain sprockets must match, otherwise the tool will not work)
- You are using a different bus, shorter or longer.
About replacing an asterisk on a chainsaw:
Is it wise to try to fix or sharpen the star?
The cost of this spare part is small, and self-repair or an attempt to restore a worn part never leads to the efficient operation of the chainsaw. It is recommended to replace the part with a new one if there are signs of wear.
How to unscrew an asterisk on a chainsaw:
When and why you need to replace a worn out chainsaw sprocket
Drive sprocket for chainsaw or chain saw. One of the most important parts of a gazing apparatus. The main function of the chainsaw sprocket is to transfer engine torque to the saw chain. This transmission is via a centrifugal clutch. By types, sprockets can be divided into professional and household, as well as chains. During the operation of the chainsaw and sawing wood, the drive sprocket, like the chain, gradually wears out.
Let’s find out in more detail why you need to replace a worn chain sprocket or saw and when it is better to perform such a replacement.
About replacing a chain sprocket on a chainsaw or saw. Are there ways to extend the life of an existing sprocket?
The main ways to extend the working life of the chain saw drive sprocket:
- Use multiple chains (preferably. Three). This method is the most gentle and convenient for the owner of the chainsaw in that it is not necessary to constantly tighten the chain worn out by intensive work. Operation of three chains in turn will save the resource of the sprocket and delay its replacement;
- Quality maintenance of the drive sprocket bearing. This part plays an important role in the function of both the drive sprocket and the motor. It is recommended to use a special lubricant for lubrication. The sprocket bearing is NOT engaged constantly, but only at idle speed, therefore it needs periodic lubrication. Tire nose grease can be used, such as standard grease from Repsul or Husqvarna.
Algorithm for self-replacement of the clutch drum with an asterisk
How is the drive sprocket replaced with a saw or chainsaw. Further on this in detail.
For the sprocket replacement procedure, you need to do the following:
- Remove the chain brake cover and pull it towards you (avoid contact of the brake band with the clutch parts)
- Using a wrench, loosen the nuts holding the chain tension and the chainsaw cover;
- Remove the chain and then the bar by removing debris and sawdust from the mounting holes;
- We fix the piston in the cylinder using a regular cord, but if possible, you need to use a piston stopper or a special lock;
- The clutch begins to rotate and do this until the piston touches the outlet;
- After that, the stopper or lace is lowered into the candle opening and fixed there, tie a few knots (the stopper will fix itself)
- We unscrew the clutch nut (pay attention. The thread of this nut is left, Take this into account when unscrewing)
- It is forbidden to use hard tools, so as not to break the soft metal of the clutch nut;
- Next, the clutch is removed;
- After removing the sprocket gear itself;
- Replace the old sprocket with a new one;
- The assembly of the structure is carried out in the reverse order.
Practical tips for repairing chainsaw tires with your own hands
Chainsaw. A very useful thing in the household. After all, with it, a lot of problems of home construction, gardening and landscaping are quickly and easily solved. Chainsaws. Quite a whimsical tool, however, if handled correctly, it is an indispensable assistant. In which there is one weak point: the guide rail. It is she who accounts for most of the operational loads. And this means that knowledge of why tires fail more often than other parts of chainsaws and how to replace them correctly if necessary will help you more than once to save money and time during seasonal or design work with a tool.
Replacing the tire of the chainsaw and its fasteners
Chainsaw tire fastening diagram
Replacing the fasteners and tires of the chainsaw is necessary when:
- Critical wear of the seat or shank elements.
- Damage to the casing.
- Violation of fixing bolts.
- Damage or deformation of the tire body.
- Abrasion or breakage of the drive and driven sprocket teeth.
- Damaged chain lubrication grooves.
- Chain tensioner wear.
- Wear of the groove and tire retainer.
This is why the guide bar and fasteners are consumable parts. To replace them, you only need one universal wrench supplied with the tool. And, of course, knowledge of the algorithm for disassembly, assembly and adjustment of the mechanism.
Chainsaw with tire removed
To disassemble the tire mounting you should:
- Place the engine in a vertical position and remove the drive sprocket cover by unscrewing the Corresponding nuts;
- Lift the bar at the front end and return the chain clamping screw, freeing it from the bar groove;
- 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 put it aside;
- If there is any damage or signs of wear, the cover and mounting gaskets should be replaced;
- Remove the chain bar to be repaired or replaced from the groove.
Chainsaw bar mount
Mounting the guide bar
It is not safe to operate a saw with a faulty tire. Therefore, at the first signs of a breakdown of the unit, you need to turn off the motor and find out what is wrong. Knowledge of the design features of the tire and its attachment to your chainsaw will help you to successfully eliminate the cause of the malfunction.
The bar also determines the length of the cut, guiding the chain. But the basis of the mechanism is still the fastening. It fits into the groove between the inner plate on the motor housing and the outer plate located on the chain guard. The busbar and casing are fixed with a bolt connection. This part of the mount is called the “engine unit” and its shape and design depend on the model of the chainsaw. The tire holder and the drive sprocket are covered with a separate cover.
Chainsaw bar mounting studs
The drive links of the saw chain fit into a guide groove on the edge of the bar and engage with a drive sprocket connected to the PTO shaft. When loosening the fixing bolts, the bar can move. The chain tension can be adjusted manually or, as on professional chainsaws, automatically. Finally, a stop is located at the front of the bar mount. It serves to securely fix the cutting axis when the moving chain comes into contact with the tree.
Chainsaw drive sprocket: with removable and stationary crown
A good tire should provide adequate chain tension. To check it, 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 wrench
Guide bar weaknesses
Saw bar device
Currently, there are various types of saw bars on sale, which differ in:
- Body length and width;
- The size of the gap;
- 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 are standard for most amateur and professional chainsaws, but structurally they can be divided into open and closed. Obviously, the former are inferior to the reliability of attachment to the body of the latter, i.e. The busbar cover and bolt connection are subject to increased loads. You also need to Watch the integrity of the sprocket teeth. When blunt or chipped, it will quickly deteriorate the leading chain links.
Parameters and versions of chainsaw tires and their elements in the photo
Your chainsaw tire needs regular maintenance. After each session of work, its grooves must be cleaned of dirt and sawdust, otherwise the lubricant will not go to the chain. The wear of the tire groove should be uniform, therefore it should be turned over from time to time. In addition, before starting work, always check for the presence of oil on the body of the chain and in the gap.
Checking the operation of the lubrication system
It is not recommended to use more than three chain sets with one bus. During operation, the gap, despite all the strength of the metal of the tire body, expands, which leads to the appearance of backlash 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 sprocket. Applied to the toe of the tire.
Separate sprocket lubrication system
The sequence of actions when removing the tire of the chainsaw in the photo
After that, the chain must be put on a new tire and the last one must be installed in the groove to be 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.
The chainsaw is back at work
If the new tire is attached and the headset is installed correctly, the chainsaw is ready for use again. By the way, just in case you should make sure of this by sawing several thin branches.