Stihl chainsaw do-it-yourself starter repair

To quickly start any chainsaw, a starter is required. With accelerated scrolling of the crankshaft of the tool, the fuel-air mixture supplied to the engine is compressed and subsequently ignited. Therefore, the normal operation of the starter for a chainsaw determines the performance of the entire mechanism.

Almost all leading manufacturers of chainsaws complete their products with starters of a similar principle of operation. It is no coincidence that specialized stores offer universal starter designs that are equally successful for both Stihl, Husqvarna, Makita chainsaws, and for Chinese semi-official fakes under the named brands. Some features have only domestic-made chainsaw starters (Lesnik, Ural and a number of others).

The principle of operation of a starter for a chainsaw is as follows. A handle is installed in the groove of the body, through which the cable is passed. If the handle is raised sharply, the cable is pulled out and engages the ratchet drum, which transmits the movement to the splined drum provided on the shaft. In this case, the crankshaft makes several revolutions, and the working mixture in the space between the piston and the cylinder head is compressed. Accordingly, when the handle is lowered, the contact between the ratchet and the splines is lost, and the shaft stops.

With an increase in engine size, the required amount of the fuel-air mixture necessary for its subsequent ignition also grows, so the number of jerks for the starting cable for high-power saws increases. Therefore, in order to accelerate the return of the drum, unwitting return springs made of steels with high elastic properties are used.

Facilitating the launch of a chainsaw is implemented in the following ways:

1. Preliminary enrichment of the working mixture, for which there is a special damper in the design of the carburetor.
2. Installing an automatic decompression valve that reduces the working pressure in the chainsaw cylinder.
3. By installing an additional spring, which, in the process of moving the cable, facilitates the unwinding of the crankshaft.
4. The presence in the design of some chainsaws (for example, Partner S series, Maxcut, etc.) of a primer - a pump that provides preliminary pumping of fuel.

With frequent starts of the chainsaw, some parts of the starter are constantly subjected to dynamic loads. As a result, the cable may burst, several teeth of the ratchet may crumble, and the shaft will rotate at a much lower speed. Therefore, the revision and even repair of the starter are operations that are sometimes carried out several times per season.

When it is pulled out, the cable constantly rubs against the starter housing. To replace, the assembly body is disassembled, and the ratchet drum is carefully lifted in such a way as to prevent the return spring from jumping off its sockets. It is better to do this work together: the assistant fixes the spring while the cable is being replaced. After fixing the cable in the handle and in the grooves of the drum, the cable is wound on the roller, and the body is assembled.

If the material of the starter spring is of poor quality, the spring bursts (usually at the point of its attachment to the drum, where it forms a loop). In this case, it is not necessary to replace the spring.It is enough to thoroughly clean its surface from dirt and traces of grease, gently grind the place of destruction, and then release the spring at 600 ... 650 ° C (the spring steel should acquire a crimson color). It is necessary to cool the spring slowly, and at 100 ... 150ºС it is already possible to carefully wrap its end in the form of a restrictive ledge on the inner surface of the drum (the steel will acquire the necessary plasticity) and insert it into place. The elastic properties of the spring will not change.

Putting the starter spring in the right groove is not an easy task even for an experienced user. First, the spring should be twisted to the previous diameter and installed in the cavity of the drum hub. The outer end of the spring is fixed by the restrictive ledge, and the outer end with a screwdriver should be placed opposite the hole in the lock. The loop at the inner end of the spring is combined with a screwdriver with a hole, after which the disk is lowered. By rotating the disc, check whether the ratchet pawl is in place. Next, the ratchet itself is assembled.

After installing the spring, it is necessary to adjust its tension. To do this, a cable is inserted into the groove on the circumference, and a return spring is twisted around it. After eliminating the slack, it is better to wind the spring a few more turns to ensure the required preload on the part.

Repairing the ratchet itself at home is not recommended, since many operations will require the use of a CNC machine. It is easier to purchase a new node in specialized stores.

Today we will look at the problems with chainsaw starter malfunctions and we will remove them. This type of breakdown is not uncommon during intensive use of a gasoline-powered saw. And in our case, in logging, this happens systematically.

I happened to repair starters from the Ural chainsaw, with which we felled the forest while working in the forestry. I was still very young and dealt with the design for the first time, myself. The malfunction arose due to the breaking of the “tongue” of the spring, which is fixed in the drum (case). I remember how I was covered in graphite grease (hands and face) trying to tame the “snake” (metal tape), which “fell apart” into rings and did not want to gather in the bay))). I think whoever assembled (twisted) the spring remembers , as cramps palms from the constant resistance of the spring. The repair was also aggravated by a metal cable. Nevertheless, I successfully coped with the task, although it took me a lot of time and nerves. On chainsaws of world brands, the design is not so complicated and capricious.

So, the chainsaw starter is designed to start the tool. On gearless saws, it is located in the side cover on the flywheel side (left side of the tool). This is a purely mechanical principle of operation. But in order to competently and efficiently repair the starter, it is necessary to understand the principle of its functionality (work). I suggest that you carefully consider this issue.

On top of the cover (body) of the starter, there is a handle in a special seat of the cover. The handle is connected to a cord, which in turn is wound on a pulley and the end of the cord is fixed to the pulley. When the operator (chainsaw user) pulls the handle up with a jerk, the cord unwinds along the pulley (coil), bringing it to a "centrifugal" state. The pulley has in its design (on the back) a ratchet - this is a gear with teeth rounded to one side. The teeth of the gear (ratchet) mesh with the "dogs" that are located on the drum (flywheel) of the crankshaft. The crankshaft rotates, the fuel is compressed under the pressure of the piston and the “engine” head. The operator, meanwhile, lowers the handle, the return spring, which is fastened to the coil (pulley), winds the cord to its original state (on the coil). The teeth of the ratchet, meanwhile, slip along the "dogs" of the flywheel, excluding contact with them, since they already rotate in the opposite direction.I remind you that the ratchet teeth are rounded in one direction - it is this principle that allows engagement with the crankshaft splines. Rotating in the opposite direction, engagement with the "dogs" is excluded.

But, as lumberjacks know, a pulley comes with a ratchet without characteristic teeth - gears. These are classic pro chainsaws, the ratchet of which is either a steel "cup" of small diameter with side cutouts (protrusions), or plastic counterparts (grabs). For example, on Calm 361, the ratchet has dog grips. It is these "cutouts", "captures" or "dogs" that engage with the splines - "dogs" on the shaft. The principle of operation of splines - “dogs”, I think, is understandable - when the shaft accelerates in rotation, the “dogs” slip along the ratchet.

Let's take a look at the general circuit of the starter.

In addition, the starter comes with a damper spring, the so-called "easy start» smart start. On a chainsaw model with an “easy start”, the letter “e» (e.g. Husqvarna 340e). However, there are models of professional chainsaws without the letter “e”, since they have no analogues without the Smart Start system. The starter cover, with the presence of a damper spring, looks more convex. By the way, damper springs break quite often than the main spring.

While working on a shift, we encountered a similar problem - on a Husqvarna 340 loppere the spring burst (there is no damper spring on the analogue Husqvarna 340). And on the watch, every hour of road operation, they worked according to the 10 × 4 scheme. It was not possible to replace and repair the damage. I had to use a “horned” chainsaw and a crosscutter to periodically saw off the branches so that there was no downtime for the tractor driver. The bough cutter had to take an axe. The next day we replaced the starter - we put on a cover from a similar chainsaw (I don’t remember the model, but not the Husqvarna 340), which had a design without a damper spring. Of course, the lid did not fit completely, there was a gap on top, but the seat fit. However, this was the only way to solve the problem, there were no specialized stores in that outback, except for the Selpovsky grocery ...

So, you have a chainsaw starter “covered up”. If the cord simply breaks, then the malfunction is “obvious” and it should be replaced. Other typical signs of a starter failure are as follows:

• the shaft does not seize (the winding cord scrolls freely);
• after a jerk of the winding, the cord does not wind up;
• starter jammed

The first step is to wrap and remove the cover, make a visual inspection. The breakdown of the chainsaw starter can be different - a broken spring, a pulley (“coil”) defect, a worn winding cord.

Next, we prepare the tools for repair - these are screwdrivers and round-nose pliers. In the event of a break, you will need a new cord. I think that lumberjacks have a starter cord in stock. If it is not possible to purchase a factory cord, then you can replace the “pulled” with a clothesline, choosing the appropriate diameter.

We unscrew the starter mounting screw, remove the clamp and damper spring, if any, on your brand of chainsaw. We dismantle the pulley with the cord, untie or cut off the knot of the cord, remove it. Since the cord is torn, the spring is discharged, and, in principle, you can not be afraid of the spring falling out of the cover.

Loosen the starter mounting screws.

The cord is torn, the spring is discharged, you can not be afraid of the spring falling out of the cover when disassembling.

We dismantle the torn cord from the pulley

We remove a fragment of a torn cord from the handle

We take a new cord, select the appropriate length (focusing on the length of the old broken cord), divide, melt the ends of the cord so that they do not “discharge”.We put a new cord into the coil, tie a fixing knot and “hide” it in the pulley for the cord to move freely along the coil stream (on some models of chainsaws, the cord is tied around the ratchet - as provided by the design). We pass the free end of the cord through the hole in the starter cover and put it into the handle. We fix the cord in the handle with a knot. We wind the cord on the coil (pulley) in the appropriate direction. We place the pulley in the starter cover on top of the return spring (and on top of the damper spring, if any) and make sure that the spring is engaged with the coil - we slightly turn the coil in the appropriate direction. We fix the pulley with the fixing screw.

We measure the new cord by the length of the damaged cord

We melt the end of the cord before threading it into the pulley so that they do not “discharge”.

We put the melted end of the cord into the technological hole through the pulley

We put a new cord into the coil.

Tie a knot at the end of the starter cord with round nose pliers.

We “hide” the tied fixing knot in the pulley for the smooth running of the cord along the coil stream

We pass the free end of the cord through the hole in the starter cover and put it into the handle.

We put the free end of the cord into the handle.

We tie a knot at the end of the cord in the handle for fixation

We melt the loose knot of the starter cord in the handle

Next, you need to charge (cock) the spring. To do this, pry off the free part of the cord with a screwdriver and pull it out. We grab the cord with our hand, place it in the technological half-hole, which is located at the edge of the coil. We make several turns by turning the coil (pulley) by the cord in the direction of tension.

We pry the starter cord with fingers or a screwdriver, pull it off and wind it on the coil.

We wind the cord on the pulley in the direction of tension

We make several turns of the cord on the pulley for an acceptable tension

Too little tension will "break" the edge of the pulley housing, and too much tension will adversely affect the return spring. Choose your tension.

We check the tension of the cord in the starter by pulling it up by the handle

Reinstall the starter cover and secure with screws.

When the spring is charged, the starter is installed in place - the cover is screwed to the chainsaw. During screwing, the mounting screws are slightly tightened, and the starter must be turned to fully seat and engage the pulley with the flywheel "dogs".

When you try to start the chainsaw, the jerk of the cord is “idle”, i.e. there is no engagement with the shaft. The operator jerks the starter to no avail, the cord unwinds along the pulley without resistance and rewinds. What is the reason?

The fault lies in a broken damper spring ("easy start», «soft start mechanism"). If you remove the starter cover, then a breakdown is detected without difficulty, since most often the spring bursts closer to the cover. However, it is not the damper spring itself that may break, but its mounting location.

If the spring has burst, then only replacing it with a new one will help to eliminate the malfunction. That is why I am not a fan of chainsaws with a soft start system. Of course, I don’t impose my tastes and opinions on any of my colleagues - everyone has the right to decide their own preferences in this choice of chainsaw model.

Another reason for the lack of reliable engagement with the shaft may be a defect in the ratchet. This is a model of ratchets with a plastic gear, when the teeth for engagement are cracked and chipped. In this case, it is also necessary to replace this node - that is, the ratchet mechanism. And it is better to have a chainsaw model with a steel ratchet.

By the way, the "dogs" on the flywheel shaft can also be covered - the springs that perform the return function will burst and, as a result, the clutch with the ratchet will disappear. A similar malfunction in my personal practice also occurred.The springs of the "dogs" were made from fragments of the cable (from the cores). But it cost incredible patience, time and focus. I am sure that you should not pervert like that and work out with another chainsaw.

Another reason when the shaft does not seize is the banal mistake of reassembling the starter - fixing it to the flywheel. This picture is observed in inexperienced lumberjacks. The reason is the lack of engagement of the coil with the "dogs". The fact is that during the final screwing of the cover, the user of the chainsaw does not check the engagement by turning the starter and the ratchet lies on top of the “dogs”, and in this case there is no engagement. An inexperienced operator is perplexed and does not understand the cause of the malfunction. He disassembles and assembles again until he guesses (or until a more experienced colleague tells him) about the competent collection of the starter.

The picture, when the starter is jammed, is as follows: the operator jerks the cord by the handle, and the cord either does not move at all (the pulley does not turn), or with great difficulty “passes a short distance” and finally stops. Of course, no return movements of the cord to its original position occur.

I am sure that a similar picture is familiar to most lumberjacks. The cause of the malfunction lies in the wear of the pulley, or to be more precise, in the support casing that holds the cord in the "stream" of the pulley. The cord goes beyond the edges of the housing, crawls out, it is rubbed between the edge of the casing and the pulley, and the cord loses its ability to roll back to its original position.

To continue working, you need to rewind the cord onto the pulley, “charge” the spring. To start the chainsaw, you need to “catch” the engagement by carefully pulling the cord up by the handle and only then pull. The cord must be in a taut position when pulled to prevent it from falling out of the reel body. This method will help only for a short time of using the tool, since the wear of the assembly is irremovable - it is necessary to promptly replace the starter coil with a new one.

You should pay attention to one important nuance: during the dismantling of the pulley, it is important that the return spring (if it is intact) does not fly out of the seat. Otherwise, you will get tired of collecting the spring in the bay and laying it in place. In order to avoid falling out of the return spring from the seat, it must first be discharged. This is done as follows: the cord (closer to the handle) is picked up with a screwdriver and placed in the technological half-hole of the pulley. Next, you need to pull out the cord and make several turns in the opposite direction of winding until the spring weakens. Another option for unloading the spring is to cut off the cord at the base of the handle, but by doing so you will sacrifice a small piece of the cord. When removing the pulley, make sure that there is no engagement of the spring with the pulley.

The return spring serves to wind the cord onto the pulley and is located under the pulley. If it bursts, and this depends on the resource (as a rule) of using the tool, then there is only one way out in this situation - to replace the spring with a new one. You can, of course, pervert, and “blind” a short analogue from fragments, but this is only in the case when there really is an “edge” and it is necessary to finish the work in the cutting area. The end of the spring tape will need to be annealed to take the form of a fixation hook. Such forced absurdities happen, as a rule, on the watch and the “Russian peasant” has to “surprise the world” (or amuse) with his ingenuity. But in reality, to eradicate poverty in order to feed the family.

If the spring burst, then for replacement we remove and throw away its remnants. In its place, we install the bay of the new spring. We cover the spring with a protective cover.

The coil (pulley) is mounted on the spring (on top of it). After that, it is necessary to turn the pulley, making sure that the coil is engaged with the return spring.Then we proceed in the order indicated in the chapter. "In the event of a broken cord".

Write comments, supplement if I missed something, didn’t add it, or made a mistake somewhere. I will be glad to our discussion.

A chainsaw is the main tool with which you can stock up on firewood for a bath or fireplace, and you can also use it for construction work in a summer cottage or in a private house. Subject to all operating conditions and the implementation of preventive measures that are provided by the manufacturer, the chainsaw can last a long time. But after a while, minor malfunctions may occur that you can deal with on your own. For example, do-it-yourself repair of a chainsaw starter is quite possible, subject to the sequence of operations.

Chainsaw starter device: 1 - starter screw, 2 - bushing, 3 - easy start spring, 4 - screw, 5, 6 - starter coil, 7 - deflector, 8 - starter cover, 9 - handle and cord, 10 - screw.

The most common tool failures include:

• problems in the ignition system;
• stopping the chainsaw in the process of cutting;
• loss of power during operation;
• wear of some structural elements of the chainsaw (brake band, drive sprockets, anti-vibration parts);
• problems in the fuel supply system;
• starter related problems.

In addition, it is necessary to carry out a visual inspection of the chainsaw before starting work and preventive measures. These include chain lubrication, control of the amount of fuel mixture, as well as the presence of the required amount of oil.

The spark plug is unscrewed to check its condition.

Each of the faults is eliminated according to its technology. So, for example, repairing the fuel system of a chainsaw should begin with an inspection of the appropriate filter. After that, the correct adjustment of the carburetor is checked, which is carried out with the help of screws. The gaps must be set in strict accordance with the manufacturer's instructions, which must be included with the chainsaw. The repair of the ignition system includes inspections of candles. If a strong deposit is detected, the gap changes or other visible damage is detected, this element must be replaced.

Problems with the starter may prevent the tool from starting. That is, after the cord is pulled, the chainsaw does not start working.

The causes of the malfunction are:

• pulley breakage or crack;
• broken spring;
• starter cable break.

Before repairing the starter, it is necessary to prepare the tools with which to carry out the work:

• a set of screwdrivers or a special tool that is supplied by the manufacturer with the tool;
• a rope that will be used as a replacement for a broken cord if necessary.

A large amount of black soot on the spark plug indicates a malfunction in the engine.

Before proceeding directly to repairing the starter and finding out the causes of malfunctions, it is necessary to remove it from the tool body. To do this, unscrew a few screws holding the side cover to which the starter is attached. This is done with a screwdriver or a specialized tool.

After the lid is unscrewed, it is turned over and inspected. Next, unscrew the screw with which the starter is fixed. After that, the clamp and spring are dismantled for a smooth start. Now the pulley on which the cord is wound is available for removal. After the knot on the rope is untied, it can be pulled out from the pulley and replaced with a new one. Provided that the loss of starter performance is associated with a break, this may be enough to eliminate the breakdown. However, the remaining parts that make up this element of the chainsaw should be carefully examined.

When inspecting the components of the starter, the following malfunctions can be detected:

The most common damage to the soft start spring occurs at the end where it is visible when disassembling the housing.

1. The pulley may be damaged. There may be cracks or tears, and there is damage on the back. As a result of these problems, the tool cannot perform work.
2. Damaged soft start spring. In this case, both the spring itself may be mechanically faulty, and there may be defects in the place of its fastening. The weakest point of this element is precisely the mounting point and the tip of the spring, which is inserted into it.

If defective or partially damaged starter parts are found, they must be replaced with new ones. In this case, the new elements must correspond to the saw model being repaired.

After the repair is completed, it is required to properly assemble the starter.

The pulley is mounted on top of the spring. In this case, it is necessary to check how much they grappled with each other. In continuation of the repair, it is necessary to wind the pulley. This must be done in such a way that during rotation it pulls the cord into the starter. It is enough to make 3-4 turns to give the required voltage. Previously, the rope is threaded through the hole in the cover of the chainsaw.

You may have to make a few more turns to align the cord fixing holes in the pulley and housing. A new rope is threaded into the technological hole and a loop or knot is made: this will allow it to slip out of the pulley. The rope is taken aside so that it does not interfere with further work. Next, you need to fix the pulley.