The Champion 254 chainsaw does not develop speed. Do-it-yourself chainsaw repair: analysis of the main breakdowns and methods for eliminating them

There are often cases when owners of chainsaws are faced with their breakdown and it does not matter at all what model of this type of equipment, since the nature of the breakdowns is almost the same for all. Well, the chainsaw has stalled, so what next? Undoubtedly, you can take the equipment to specialized services that will repair your “iron friend” for a fee. But as they say: why pay more?

After all, you can personally disassemble the instrument and repair it, since the damage may be insignificant, but in the service you will pay a lot for this. But naturally, in order to bring a tool back to life yourself, you need to be able to understand the reasons for its breakdown and how to troubleshoot it. So let's learn! In this article you can find answers to questions regarding situations when the tool simply stalls after directly pressing the gas. So let's get started.

Basic elements of chainsaws

Before we begin to delve into the issues of tool breakdowns and repairs, let’s first figure out what the chainsaw itself consists of. First of all, I would like to note that this tool belongs to the category of equipment whose operation directly depends on the internal combustion engine.

It is also important that chainsaws are equipped with a single cylinder engine, and which operates on a type of fuel such as gasoline. It is worth noting that, despite its similarity with other tools, it does not have a gearbox. And it is replaced by a kind of single-stage chain transmission, through which the chain (saw) itself moves.

In fact, a chainsaw is a fairly simple design, but this does not prevent it from being reliable, practical and capable of fully ensuring immediate uninterrupted and cyclic operation even in quite difficult conditions. This tool consists of a huge range of certain elements “vital” for its correct and productive operation. This is a carburetor, a direct chain tensioner, a tire equipped with a chain and other elements.

Characteristics and possible causes of failure. Fixing the problem yourself

Chainsaws are fairly reliable and simple designs. Therefore, if you properly care for them and handle them based on the manufacturer’s recommendations, then they fail very rarely and various types of breakdowns are quickly eliminated. But if you are faced with this situation and want to repair your instrument yourself, without resorting to the help of professionals, then delve into the information presented below.

In fact, it is impossible to clearly and accurately determine the reason why or stalls when you press the gas, since there are quite a lot of factors influencing this. But do not forget that starting from the fact that the chainsaw is equipped with a simple two-stroke engine, such conditions as lubrication, fuel, spark and air are important for its effective performance.

Consequently, the carburetor directly prepares the fuel-air mixture, the filter cleans the air from dust, the ignition unit and spark plug create a spark, and the gasoline contains lubricant.

1. An important fact is that for trouble-free operation of the tool it is necessary to pay close attention to the fuel itself. Since if this kind of mixture is not prepared correctly, then most chainsaws simply will not start. Consequently, not every owner will think to look for the cause of the breakdown in the fuel. That is why, in order for your tool to always work correctly, you need to use only high-quality gasoline for the mixture.
   

   And also use only the oil that is made by the manufacturer of your tool. In addition, it is important to prepare this kind of mixture in the quantity that you will definitely use in one or two weeks, but no more (see).

   Because otherwise, overexposure of the mixture directly in the canister will lead to it losing all its octane properties and this will lead to significant problems with the instrument.

2. The cause of the breakdown may also be a direct pouring the mixture into the candle at the moment when the mechanism is started. In order to solve this problem, you need to turn out and dry the candle, but remember that it should not be heated under any circumstances. Excess fuel must be drained through the hole (spark plug), wait 20-30 minutes, then put it back in place and try to start the tool again.
3. The chainsaw stalls when you press the gas because no spark. This can happen when there is no good contact between the tip of the spark plug and the wire (high voltage). However, if this kind of connection works correctly, but there is still no spark, then the ignition unit (electronic) is the cause. It is important to note that these types of spare parts cannot be repaired, so they can only be replaced.

   

   Do not forget that by examining the spark plug you can obtain significant information regarding the breakdown of the chainsaw. Since if its surface is dry, then the reason for this is the cylinder, into which fuel is not directly supplied. That is why you will have to check the entire range of its supply step by step. If the spark plug is covered in black soot, this means that the carburetor is not working properly, that is, it supplies either a lot of fuel or pours oil directly into gasoline.

4. If the chainsaw stalls when adding gas, this means that fuel is supplied in insufficient quantities for full operation of the chainsaw. The reason for this may be either a clogged carburetor (its jet) or contamination of the filter itself (fuel). Remember that the first unit should be checked exclusively by professionals, but you can clean the second one yourself.
5. In addition, the cause of failure may be filter (air) if it is contaminated with dust. But do not forget that each model has its own easily eliminated and characteristic features. It is for this reason that do not hastily start disassembling and repairing the instrument, but it is best to “walk” through the forums, where there are a huge number of reviews from various owners, so as not to make things worse.
   

   Since, for example, a chainsaw stalls when you press the gas for a simple reason, namely a simple blockage of the direct breather.

   In order to solve this kind of problem, all you have to do is disconnect the (fuel) hose from the carburetor and pay attention to whether fuel is leaking out of it. Since if the mixture flows in a full stream, this means that the breather is not contaminated, but if on the contrary, then the cause of the breakdown has been found.

6. Here is another reason why a chainsaw stalls when you press the gas - muffler. It is this part that can interfere with the full operation of the tool in cases where it is directly contaminated with exhaust resinous deposits. To do this, you just simply need to clean it.
7. Quite often the chainsaw partner stalls when pressed and the reason for this is cylinder-piston group. Since by examining them, namely the piston and cylinder, you can easily determine the cause of the tool malfunction by directly replacing them. You can also directly bore the cylinder itself relative to the dimensions of the new piston.

   

   But if after inspection you find that there is no damage on both the piston and the cylinder, then the reason may lie directly in the rings (piston). To do this kind of check, you need to insert a piston into the cylinder and carefully begin to rock it using a connecting rod. If you suddenly feel play, then the rings need to be replaced, as they are already worn out.

8. Many people wonder: why does the chainsaw stall when I press the gas? The answer may also lie in insufficient chain lubrication(see), since the oil line may leak, or the immediate channels may simply be clogged. That is why pay attention to the chain, because if it is dry, then without delay, start cleaning the channels that supply oil directly to the tool tire. Then inspect in detail the parts where the oil pump fittings are connected to the pipes. But if you notice that oil is leaking at the joints, or you find cracks in the tubes themselves, then in the first case, seal the leaks with sealant, and the tubes will have to be replaced.

First of all, what you should remember when purchasing this kind of tool is that certain parts of the saw need to be replaced with new ones after their service life (passport) has expired. It is for this reason that the instructions should always be at your fingertips, since everything is described there in detail.

These types of details include: sprocket (drive), tire, part of the system (anti-vibration), as well as a chain. Since we should not forget that if this “filling” is not replaced with a new one at the required time, then these worn-out spare parts will negatively affect the remaining parts of the chainsaw. It is for this reason that you should check the depth of the immediate tooth cutting quite often. Remember that it should not be higher than 0.5 mm a week.

To sum it up...

Definitely, every item we buy has its own expiration date and sooner or later it breaks, and it becomes a shame when the degree of its breakdown is so great that it cannot be repaired. But you must admit that quite often we simply treat technology negligently (see about proper operation and that), and when it stops working, then we try to find ways to fix the breakdown, turning to a huge number of services.

But remember that even though the equipment breaks down, we can extend its “life”. All you need to do is simply take care of it, run it in after replacing parts (read how it happens here) and keep its parts clean and in order. And then, undoubtedly, it will serve for many more years. It is also important to use exclusively high-quality spare parts and “additives” (see). Then your equipment will work smoothly, and you will simply forget what repairs are.

Situations why chainsaw stalls- so many. Since it is a technical mechanism, at the slightest deviation it tends to react through partial or global breakdown. There is a list of the most common malfunctions, the causes of which we will consider in this article:

1. The mechanism stalls immediately. The tool cannot start fully, the reason is in the parts of the unit that take part in the start of the tool’s operation.
2. Under load. The problem is in the fuel system or air filter, as the pressure on all components of the tool increases significantly.
3. When tilted. The fuel tube of the gas tank, when positioned on its side, is in the air, and not in the fuel mixture.
4. At high speeds. The problem may concern three spare parts: the fuel pump, the gasoline filter and the air filter. The filter must be washed and cleaned, and the fuel pump must not leak liquid. Otherwise, it needs to be replaced with a new one using the Kosi Kosa store.

With us you can have others, we will be happy to answer all your questions and suggest possible solutions to problems even in hopeless situations with the tool.

What to do if the chainsaw starts and stalls

One of the most popular situations when working with a saw is when chainsaw starts and stalls. This can happen with both a new and an “experienced” tool, and there are more than enough reasons for this. The most common of them is the lack of the required amount of fuel in the gas tank. It doesn’t matter what kind of saw you have, a Chinese Husqvarna or an original Shtil: if there is not enough fuel, then the problem in question arises from this. So, if there is little fuel, then you need to increase its volume in the tank by preparing the required amount according to the established proportion. How to do this - look in the instructions; the brand of oil that needs to be used is also indicated there. An interesting nuance with gasoline - it must have a maximum octane number, its quality depends on this, and accordingly the operation of the saw itself.

For the sake of economy, many saw users, and most often this happens with the domestic brands Ural and Druzhba, do not drain excess fuel, leaving the saw to “winter” with it for many months. This is strictly forbidden to do, firstly, for fire safety reasons, and secondly, in order to avoid deliberately provoking the breakdown of your instrument. There are also other situations when chainsaw owners manage to add new fuel to the old fuel, forgetting about the lost qualities and the possible chemical reaction of this “explosive mixture”. This absolutely cannot be done.

In addition to fuel, you also need to check the spark plug. Remove excess carbon from it or replace it with a new one, check the contact with the high-voltage wire and, if the gap is more than 0.5 mm, carry out a mandatory replacement of the spark plug.

For owners of saws of the popular Partner 350 brand and other lesser-known analogues, which include Chinese products, it is important to approach the issue of a stalled saw very delicately, especially if it is heated up. Do not rush to disassemble the entire structure into parts, consult with specialists. In addition to products that play a huge role in the ignition and continuous operation of the saw engine, you can also find here, which is the main cutting element of the entire structure.

The chainsaw stalls when you press the gas - reasons and solutions

Even an amateur in working with a chainsaw should distinguish between two situations of a stalled saw: if chainsaw stalls when pressing gas, then there is an insufficient supply of fuel, and the load means not only an increase in gas, but also a complication of the work of all other components of the saw that were not previously involved in overcoming obstacles. What we mean here is that the moment when the saw collides with the element that it must cut, that is, wood, it operates at a stronger power than when the gas is normally pressed.

A saw that stalls when gas is added may indicate a dirty fuel filter, which you can clean yourself. If the carburetor jet or another component does not work, then it is better to have it repaired. If the saw starts and stalls, the cause may be fuel liquid poured onto the same spark plug, or a dirty air filter.

When heating any tool, you should not inspect it, you need to let it cool, and it is better not to check any hot part, in order to avoid unforeseen situations. If you had to replace some component or global part of the mechanism, do not despair: our service will be happy to help you with this.

Is repair needed if the chainsaw stalls at idle?

Everyone knows the situation when, at idle speed, his tool simply stalls. This happens with almost all devices that have a motor. The main reasons:

• stalls at idle due to clogged air or fuel filter;
• lack of spark due to a bad spark plug;
• Carburetor misalignment, as one of the most important reasons for a stalled saw, can also be the reason why this happens when heating up. Its substandard operation also contributes to the fact that the instrument stalls “when hot.”

If your device does not idle, does not pick up or develop speed, then perhaps this is not yet a major breakdown, and with the help of our articles you can cope with it yourself. From the proposed reasons, a more realistic picture becomes clear: does your device need specialist intervention, or can you fix a breakdown at a specific level yourself. If you need to replace a specific part, for example,

Even with a strong desire, a chainsaw cannot be classified as a complex device. And let us also note: the simplicity of the design is its characteristic feature. However, despite this fact, even such a simple device breaks down, taking a considerable amount of time to repair.

The difficulty is not the repair procedure itself, but the correct identification of damage. Completely different deficiencies can cause the same breakdown. Therefore, there is no need to rush to immediately disassemble the engine or carburetor before signs of failure have been examined. There is little that can be useful here; you will have to use your own mind more.

Existing types of breakdowns can be classified into one of two categories: damage to the engine system with numerous groups and components in it (ignition, fuel supply, exhaust, cylinder-piston) and breakdowns of other components (lubrication system, brake, tire, clutch, etc. ).

When the engine is faulty

It often happens that the normal performance of the engine in chainsaws is disrupted. It is the search and restoration of damaged engine systems that takes up the lion's share of users' time. They may have the following manifestations:

• cannot start;
• the chainsaw stalls when it starts;
• job instability;
• It idles normally, but stalls at high rpms.

When planning to repair a chainsaw yourself, it is advisable to use the method of exceptions - consistently check the probable causes of damage. They start checking those that will take the least time to correct.

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Ignition system malfunctions

Absolutely all of the indicated types of engine malfunctions can be caused by malfunctions in the ignition system. If problems occur with your chainsaw, you should start looking for the problem with the spark plug. Which also has some other meaning: the condition of the spark plug will give a hint about the operation of the fuel group as a whole. If you find any problem, you need to analyze the spark plug, first unscrewing it. Why do you disconnect the wire and unscrew it using a special key?

A dry spark plug indicates that the source of the problem is not with the ignition system, but with a lack of fuel fluid in the cylinder. In this situation, the spark plug is screwed back in and the fuel group is analyzed.

If the spark plug is significantly contaminated with fuel, it means there is an excess of fuel. This phenomenon is associated with carburetor misalignment or non-compliance with starting requirements. In such a situation, the spark plug is cleaned and dried, the cylinder is released by closing the liquid supply and using a starter to ventilate the combustion chamber and get rid of excess liquid. Then the spark plug is returned and the start is repeated.

The presence of abundant dark carbon deposits also only confirms the presence of problems in the fuel system.

Violations may occur in the proportions between gasoline and oil, in poor carburetor adjustment, or in the addition of low quality oil. They wash the spark plug with gasoline, remove carbon deposits using a needle or awl, clean the electrodes with fine-grained sandpaper and put them back.

Also, in all situations, it makes sense to check the gap between the spark plug electrodes. According to its vintage, it must correspond to a value in the range of 0.5-0.65 mm. The sealing spark plug gasket also requires checking. If it is worn out or damaged, it will provide an insufficient seal to the combustion chamber. And this will cause a decrease in compression in the cylinder and problematic engine operation.

Even when checking the spark plug gives reason to believe that the damage is related to the fuel system, the spark plug is tested for spark formation. At least to eliminate suspicions that there are problems with this issue. Perform:

• putting a cable on the spark plug;
• using insulated pliers, press the spark plug nut or thread against the cylinder;
• press the starter handle and observe whether a spark appears or not.

When a spark does not occur, the spark plug is changed. If even when replacing the spark plug no spark occurs, then the high-voltage condition is analyzed for breakage and contact with the spark plug.

A lack of spark can be caused by a malfunction of the ignition module or failure to maintain the gap between it and the magnetic wire of the flywheel. The latter should be equal to 0.2 mm. In particular, violation of the gap becomes quite possible if the saw was disassembled the day before and the flywheel with the ignition module was removed. The defective ignition module is replaced.

Having completed all the steps to check the ignition system and not finding any deviations, proceed to analyze the fuel supply system.

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Fuel supply system is faulty

If, when examining the spark plug, it is determined that liquid is not supplied to the cylinder, then the probable reasons for this fact are determined. They are:

• fuel is not supplied from the tank due to the cap hole (breather) being clogged, and a vacuum arises inside the tank, creating an obstacle to the exit of liquid;
• the fuel filter located in the tank is dirty;
• fuel fluid does not flow from the carburetor or does not flow in sufficient quantity into the cylinder.

In order to diagnose the first 2 reasons, remove the fuel hose from the carburetor and observe whether fuel flows out of it or not. When it flows out in a full stream, the filter and breather are not looked at. If the flow is weak or does not flow at all, then the source of damage is considered to have been found. The breather is cleaned with a needle.

Through the fill hole of the empty fuel tank, use a wire hook to remove the fuel filter along with the suction hose. From the latter, the filter is removed and cleaned or replaced with a fresh one. Chainsaw manufacturers recommend changing the fuel filter after each trimester.

A weak flow of liquid into the cylinder from the carburetor or poor proportions between liquid and air is caused by several reasons:

• clogging of the air filter;
• unadjusted carburetor, clogging of its channels or filter mesh.

Typically, the chainsaw repair procedure is accompanied by cleaning the air filter, since it becomes dirty very quickly. When this happens, the flow of air into the carburetor is reduced, and the fuel fluid at the outlet becomes too rich, which leads to interruptions in the normal functioning of the engine.

Removing a dirty filter for cleaning is done with great care so as not to shake off dirt into the carburetor. The filter is cleaned or washed with water and a cleaning agent, dried and returned to its place.

Centrifugal clutch of a chainsaw: 1 – friction linings, 2 – springs, 3 – drum.

By adjusting the carburetor, misalignment is eliminated. As usual, this is done using 3 screws - maximum and minimum rotation, idle speed. The adjustment is carried out strictly following the descriptions in the instructions. Otherwise the engine will simply break down. Other manufacturers of chainsaws provide a single idle screw in order to eliminate unnecessary interference in the performance of the carburetor by inexperienced users.

When carburetor adjustment turns out to be ineffective, clean the channels with the filter mesh and immediately check the safety of the membrane. The carburetor of a chainsaw is considered a capricious device, so you should disassemble and clean it, understanding the full responsibility of the operation.

The peculiarity of working with it is that many small elements of its components have the ability to imperceptibly jump out of their places and get lost forever. Having disassembled such an unruly mechanism once without thinking, you may not be able to put it back together in the same form.

If you have little or no experience in carburetor repair, then it is better not to tackle it yourself, but to entrust this important undertaking to a specialist from the service center. The carburetor is sometimes cleaned there using ultrasound.

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The muffler has failed

Chainsaw fuel system: 1 – fuel filter, 2 – carburetor, 3 – manual pre-priming pump.

Often the cause of engine breakdown, especially when the engine functions perfectly at low speeds, but at high speeds it heats up and the chainsaw stalls, is clogging of the spark arrester in the muffler with combustible products, creating obstacles to full exhaust.

Repair in such a situation comes down to removing the muffler, disassembling it and wet cleaning of carbon deposits using detergents. After washing the non-removable muffler, dry it with a hairdryer. Since soot consists of carcinogenic particles, it is unacceptable to clean it dry, because toxins will enter the master’s respiratory system. After removing the muffler, the exhaust hole is plugged with a cloth.

The reason for clogging is also the reason why they use fuel fluid with an excess amount of oil (more than recommended by the manufacturer), low-quality oil or not intended for 2-stroke engines.

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Damage to the cylinder pistons group

Damage to the cylinder-piston group (CPG) is considered more serious. This includes: wear of the cylinder and piston, scratches on their walls, wear or sinking of the piston rings in the grooves, wear of the crankshaft bearings. Many of these problems cause a decrease in pressure in the cylinder and the inability of the engine to start or operate at full capacity when it heats up.

Air purification system: 1 – cover covering the fine filter, 2 – fine filter, 3 – cover covering the coarse filter, 4 – coarse filter.

The condition of the CPG is assessed in one of several ways.

1. Removing the muffler allows you to view part of the end surface of the cylinder in the opened hole. Although the visible area is small, it can still shed light on the state of the CPG.
2. Compression is measured, which is very informative regarding the condition of the CPG elements. The procedure is performed using a compression gauge placed in the spark plug hole.
3. Using a drill, a manual starter or a flexible shaft, rotate the crankshaft, immediately checking the pressure on the pressure gauge. For a saw with normal performance, it should be at least 8-9 atm (or 0.8-0.9 MPa). As it decreases, it leads to a decrease in engine performance. A pressure of 5 atm still assumes the engine is running, but at idle.

Accurate assessment of the condition of the CPG is only possible with complete disassembly of the engine: unlocking the crankcase from the cylinder and removing the piston. If nicks, chips or deep scratches are found on the latter, it is replaced. As for the cylinder, if there is damage on the surface or it is worn out, it is bored to the repair size. Low compression can be caused by wear or coking of the piston ring. A serviceable ring does not contain carbon deposits, is held freely in the piston groove, adjoining the surface of the cylinder from the inside quite tightly.

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Chain lubrication system malfunctions

Without exception, all chainsaw repair manuals contain references to damage to the chain lubrication system, which is quite common. This:

• supply of lubricant to the chain in insufficient quantity or non-supply at all;
• oil leakage.

Coarse air purification system: 1 – snow filter, 2 – mesh filter.

When the chain is dry, inspect and clean the channels supplying oil to the tire. Clogging them is not uncommon.

In case of significant (small quantities are considered normal) oil leaks, inspect the connection of the tubes to the pump fitting for leaks, which may fall off or crack. Changes in the integrity of the oil line (drips are not taken into account) can cause insufficient chain lubrication. Air is sucked into the pump, which reduces its performance. Problems with tightness can be corrected by changing the tubes or sealing them.

Cracks in the oil pump housing are considered a significant problem with the lubricant group. Then they change it.

Any tool can break and the Stihl MS 180 chainsaw is no exception. Today we will try to understand such questions as: why the chainsaw stalls when the speed increases, also at idle and at full speed. Let's consider options for diagnosing and troubleshooting problems associated with this behavior of the Shtil 180 chainsaw.

Let's say the chainsaw operates normally at idle, but when you press the gas sharply it stalls. What could be the reason? It is immediately clear that the issue is not the ignition (lack of spark), because if the ignition was faulty and there was no spark, the tool simply would not start. This means the fuel system remains.

There are a lot of malfunctions in the fuel system, and to determine the exact reason why the Stihl 180 chainsaw stalls when you press the gas, it is necessary to carry out a complete diagnosis of it. We recommend reading about common ones and their elimination.

Filter check

The first thing you need to check is the fuel filter.

In some cases, a filter clogged with dirt is unable to pass through the fuel mixture in sufficient quantities. Accordingly, there is a shortage of fuel in the system, which leads to the fact that when you press the gas of the chainsaw, the fuel burns out, and new fuel does not yet have time to arrive, as a result of which the Shtil chainsaw stalls. Also, if the fuel filter is clogged, there may be a noticeable drop in the power of the chainsaw at maximum speed, but this is with minor contamination.

Air filter

Carburetor

In order to check the nozzle, you need to remove the carburetor and disassemble it. To remove, you need to unscrew the two nuts securing the air filter and the carburetor, then remove the air filter and the engine control lever, while disconnecting the air damper control rod from the carburetor. Next, you need to slightly pull the carburetor towards you and disconnect the fuel supply hose.

You need to remove the fuel hose as carefully as possible and prepare a plug for it in advance, since fuel should come out of it.

After removing the carburetor, you need to blow it out and clean it of dirt, only after that the carburetor can be untwisted.

It is necessary to unscrew the cover of the main chamber of the carburetor; this is the one on which the compensator is installed on top. Next, use an 8 mm bolt and a length of at least 50 mm. We knock out the valve.

It is necessary to knock out the valve by placing the carburetor on a wooden stand, this will protect it from damage to the body.

After the nozzle is removed, you can blow it out using a compressor. The valve should only allow air to flow in one direction; if the valve can be freely blown in both directions, it means it is faulty and needs to be replaced with a new one. Reassembling the chainsaw after the valve has been repaired must be carried out in the reverse order of disassembly.

You can see clearly how a carburetor is repaired, or rather, how to correctly knock out the injector valve from the carburetor body by watching the video.

Another common reason why a saw may stall when the speed increases is air leaking into the carburetor. This can only be checked with a special tool, but it is worth noting that if preventive work has not been carried out on the carburetor for a long time, then you can install a new set of gaskets in the carburetor. In some cases, this helps solve the problem of its depressurization.

When disassembling the carburetor to replace the gaskets, you need to carefully inspect its needle valve, press the rocker arm and check its lifting. Sometimes, especially after the Stihl chainsaw has stood for a long time with fuel in the carburetor, the needle may burn to the carburetor body and not perform its functions. Simply put, the needle valve will not allow the fuel mixture to pass through. In this case, the saw will not work.

Why does it stall at idle?

The first and most common cause of this malfunction is incorrect carburetor adjustment. You can adjust the idle speed yourself; for this you need to have a Stihl adjusting screwdriver, which is supplied with the unit. The adjustment hole is located on the right side of the Shtil 180 saw on the handle and is indicated by the symbols “-” and “+”.

If the Stihl chainsaw does not maintain speed and stalls at idle, you can be almost 90% sure that it has a malfunction in the fuel pump operating system, as a rule, this is air leaking into the crankcase through the pan gasket, or, more often, through the oil seals crankshaft. Air leakage reduces or completely stops the impulse, which is supplied through special channels to the fuel pump of the chainsaw. As a result of this, the Stihl 180 chainsaw does not receive the required amount of fuel and stalls at idle.

Diagnostics can be carried out using a special device called a vacuum gauge.

The second way to check the performance of the oil seals is to pour gasoline into the engine crankcase and look at them; if the oil seals leak gasoline, it means they cannot provide normal pressure in the crankcase, which will make idling impossible. And when operating at high speeds, with leaky oil seals, there is a possibility of the crankshaft bearings jamming.

The algorithm for checking the Shtil 180 crankcase and seals for leaks is as follows:

1. The top cover is removed.
2. The air filter housing and carburetor are dismantled.
3. The chainsaw handle is removed.
4. The starter spins up and retracts.
5. On the side opposite the starter, the side cover and drive sprocket are removed.
6. A piston stopper is installed in the spark plug hole or a string from an old starter with knots tied on it is stuffed into the cylinder.
7. The flywheel and clutch are unscrewed, after which the parts are removed. It is worth knowing that the chainsaw clutch has a left-hand thread and unscrews clockwise.
8. The oil pump drive gear is removed.

You can see the seals, after which you need to fill the crankcase with gasoline and check for leaks. The crankcase can be filled through the fuel window in the cylinder; to do this, the piston must be raised as high as possible. If leaks are detected, it is necessary to replace defective oil seals or re-seal the pan. You can assemble Shtil 180 by following the reverse sequence of the algorithm.

Why does it stall at full speed?

Very often you can hear the question why a chainsaw stalls at full speed. There may be several reasons. First, you need to consider exactly how the saw stalled. Let's say the tool was working normally and suddenly, for no apparent reason, it suddenly stalled and the starter does not turn over. In such a situation, you can be 100% sure that the chainsaw is jammed and you need to start overhauling it.

The second situation is when the Shtil 180 chainsaw worked normally, then gradually lost power in a short time and stalled, and the cylinder overheated. In this case, the most likely reason is air leakage under the rubber pipe connecting the carburetor to the cylinder or its rupture. The mixture became lean, resulting in overheating. The cause can be eliminated by changing the pipe.

Conclusion

If the Shtil MC 180 chainsaw stalls at idle, does not gain power when you press the gas, or even stalls at full speed, it is necessary to diagnose the fuel system and check the crankcase for leaks. You can do this yourself, but you need to have certain skills. If you are not very familiar with push-pull saws, it is better to turn to specialists, since this technique is quite capricious and any mistakes are expensive.

The Stihl 180 chainsaw does not develop speed, or after you release the gas trigger, it continues to work without slowing down. These problems are quite common. Let's try to understand the reasons that result in the occurrence of such malfunctions. Also in this article we will look at how to diagnose if the chainsaw does not pull.

There may be several reasons for the lack of traction and poor speed of the chainsaw. Therefore, you should not immediately start disassembling and repairing the carburetor, since the reason may not be hidden in it.

The Shtil MS 180 chainsaw is equipped with a reliable carburetor, on which the manufacturer has limited the ability to adjust the power and maximum engine speed, so if the chainsaw loses traction, the carburetor is the last place to look for problems.

Muffler

You may ask, which is the first? The answer is a muffler. The muffler is responsible for exhaust gases and extinguishing the flames in them. All combustion products pass through it, which can clog it over time. The situation with a muffler clogged with soot is far from uncommon, and it occurs due to an incorrect fuel mixture.

With a normal ratio of gasoline to oil, combustion products are not so saturated with soot that they clog the muffler. If the amount of oil is more than normal, excessive carbon deposits will form during its combustion. Further, carbon deposits accumulate under the piston rings and in the muffler of the Stihl 180 chainsaw. Thus, a coked muffler is the most harmless thing that can happen, the maximum damage from excessive carbon deposits is the need to replace the piston.

How to check the muffler

To check the muffler, it must be removed from the chainsaw. To do this, using an 8 mm socket, unscrew the two fastening nuts and remove the part.

Important: after the muffler is removed, it is necessary to check the integrity of the gaskets between it and the cylinder, since very often they stick and break when the muffler is removed.

You can clean the part mechanically, using screwdrivers or a knitting needle, and then blow it thoroughly with compressed air. The seat on the muffler can be cleaned with sandpaper to remove burnt parts of the gasket.

The muffler must be installed in the reverse order.

Important: when tightening the muffler mounting nuts, do not over-tighten the nuts, as the threads on the screws can be stripped.

The second reason why a calm chainsaw engine may reduce power and not develop speed is a blockage in the fuel system. As a rule, the first place to start looking for a blockage is the fuel filter.

Checking the fuel filter

The fuel filter is installed in the tank of the Shtil 180 chainsaw, and it is not very convenient to remove it. To make the process easier, you can take a small piece of aluminum wire and bend it at the end, then use it to hook the fuel hose and remove it, along with the filter, from the tank. To check the filter, you need to blow into it; if air does not pass through, then the cause has been found, and the filter needs to be replaced.

If the filter is clean, you need to check the fuel hose for clogging. To check, you need to disconnect it from the carburetor and, with the air filter removed, blow into it. If a blockage is detected, you can clean the hose mechanically, using a wire, and then blow it out with compressed air.

Strainer in carburetor

The last likely place for a blockage to form is the strainer in the carburetor. In the diagram below, it is indicated by the number 13.

In order to clean the mesh filter, you need to remove the carburetor from the Shtil 180 chainsaw. The work begins by removing the top cover of the saw, after which, using an 8 mm socket, unscrewing the two fastening nuts. Next, the filter housing is removed from the guides, after which the air damper rod and the engine control lever are disconnected. Lastly, the fuel hose and throttle linkage are disconnected, after which the carburetor can be removed from the guides.

The carburetor strainer is installed in the fuel pump chamber; in order to get to it, one screw securing the pump cover is unscrewed and it, along with the gaskets, is removed.

The mesh filter can only be cleaned using compressed air. Any mechanical methods are strictly prohibited, since the mesh is very soft and easily changes shape. When you press it, it easily wrinkles and bends form along the edge of the seat, through which unfiltered fuel can enter the carburetor.

During the cleaning process, the seat with the filter installed in it must be half covered with your finger and only then blow with air, otherwise the mesh may fly away and it will no longer be possible to find it.

Carburetor depressurization and nozzle blockage

Sometimes, when the screws securing the carburetor cover are loose or the gaskets have become unusable, the chainsaw may also experience a loss of power. To eliminate the possibility of this malfunction, it is necessary to check the integrity of the gaskets and the tightness of the screws on the carburetor covers. To do this, you need to remove it from the engine (the algorithm is described above) and disassemble it. Defective gaskets must be replaced using spare ones from the repair kit for the Shtil MS 180 carburetor.

In the case where a complete check of the fuel supply and exhaust gas system has been carried out, but there are no results. The main fuel injector valve needs to be checked. To check, you need to knock it out of the carburetor body. All work should proceed according to the following algorithm:

1. The carburetor is removed from the chainsaw.
2. The four screws securing the cover with the compensator are unscrewed, after which the cover can be removed.
3. The carburetor is installed on a wooden lining, after which, using a bolt with a diameter of no more than eight millimeters and a length of 50, it is knocked out into the internal cavity of the carburetor.
4. Next, you need to select a small hose, the inner diameter of which matches or is slightly smaller than the outer diameter of the nozzle and put it on the nozzle.
5. The next step is to blow inside the hose. If it only blows in one direction, the nozzle is working properly; if it blows in both directions or does not blow at all, then the valve needs to be replaced.

All of the above actions should help in eliminating the problem associated with the fact that the chainsaw does not pick up speed, otherwise, a full diagnosis at the manufacturer’s service center will help.

Why does the chainsaw not slow down?

There may be several reasons why a chainsaw does not slow down:

• throttle spring broken;
• jamming of the gas trigger;
• the throttle linkage is bent;
• The corkscrew of the throttle shaft is lost, causing it to jam.

It is not difficult to solve all these problems; you need to conduct a careful inspection and accurately determine the cause, and then replace the faulty part. As a rule, if the chainsaw picks up speed well, idles and has normal power, then the problem with the fact that it does not slow down is purely mechanical. And finding and eliminating a mechanical fault is much easier than identifying and stopping air leaks in the chainsaw crankcase.

Video

Calm 180 does not develop speed, a video of the most common reason can be seen below. In it, the owner of the Shtil ms 180 chainsaw tells his story of solving a problem with loss of power.

Conclusion

If the first signs of loss of power (reduction in speed) appear with the Shtil MS 180 chainsaw, under no circumstances should you continue to work, but you should immediately contact a specialist or carry out diagnostics and fix the malfunction yourself. There are not many reasons for power loss and you can cope with them even without certain skills. The main thing is to calmly analyze the behavior of the saw and find out the reasons why it stopped pulling (the speed dropped), and eliminating the malfunction is not a difficult task.