Adjusting the carburetor of the Chinese Stihl chainsaw

Why does the chainsaw stall? Causes and their elimination

What to do if the chainsaw stalled? Many owners of chainsaws know the weakest points of their tool, however, a situation may arise when the reason is not immediately found, but this manual will be useful for those who have recently purchased a chainsaw.

ATTENTION! If you did not find your reason in the list below, you can ask your question in the comments. So the chainsaw stalled. There can be many reasons, because although the saw is not a Formula 1 car, it is a technical device.

Here, the main condition for a successful repair will be an accurate diagnosis of the malfunction..

You should not immediately start disassembling the chainsaw, first you need to check the simplest possible causes of the malfunction.

Carb Adjustment on The Chinese Chainsaw

Let’s take a look at the sample steps for checking the possible cause of a malfunction.

(This is the second edition of this article, in which I will try to describe in as much detail as possible all possible reasons.)

If your chainsaw does not start, then in more detail here:

Chainsaw service

Chainsaw maintenance includes:

  • Monitor the quality of the gasoline and oil you use to prepare the fuel mixture. Stick to the correct proportions while doing this;
  • Do not use fuel that was prepared more than two weeks ago. Check and clean the gasoline and oil tanks regularly, otherwise the engine will stall or the saw will not start at all;

adjusting, carburetor, chinese, stihl

Chainsaw chain maintenance

  • Clean the air filter regularly. It has a simple device and this operation does not require much effort from you;
  • Flip the bar every time after sharpening the chain again – this will extend the life of the saw headset;
  • Check regularly and thoroughly clean the oil inlet and outlet holes, oil passage and groove on the guide bar. Remember that if the automatic lubrication system is faulty, your saw will start or stall;

air filter or change it.

A dirty air filter does not allow the supply of air in the volume for which the normal operation of the chainsaw is designed. That is, if the carburetor, which mixes air and the fuel mixture, was adjusted with the same amount of air supplied, then when the air filter becomes dirty, the amount of air decreases, but the settings remain the same and as a result we get a rich working mixture.

Idle speed adjustment

Idle speed adjustment sequence:

  • The engine is started and warmed up for 5-7 minutes.
  • The screw is unscrewed, increasing the speed until the chain starts to spin.
  • Then the screw is screwed back 1/4 turn.

If there is an electronic tachometer, you need to use its readings when adjusting. Most chainsaws should idle at 2500 rpm..

Adjusting the carburetor of a Chinese chainsaw with your own hands

Adjustment is not provided for all carburetors of Chinese chainsaws. Today there are many models of household-grade chainsaws, including European brands, on whose carburetors there are simply no adjusting screws. Or there is only one idle speed adjustment screw.

Such carburetors require adjustment only when the chainsaw at idle speed makes too few exhaust (rpm) and sometimes stalls. Below in the text, the algorithm for adjusting the idle speed of the carburetor on a Chinese chainsaw will be considered.

How to adjust the carburetor on a Partner chainsaw

The chainsaw carburetor is a device responsible for supplying fuel to the engine combustion chamber. How correctly it works depends not only on the power and efficiency of the tool, but also on its economy..

  • Need for customization
  • Features of setting up the Makita carburetor
  • Adjustment screws
  • Adjusting the carburetor of a Chinese chainsaw with your own hands
  • Required tools
  • Algorithm for adjusting the carburetor
  • Idle speed adjustment
  • Nuances that arise in the process
  • Adjustment video
  • How to Set Up a Carburetor on a Partner 350 Chainsaw
  • “PARTNER 350” Correct carburetor adjustment
  • How to adjust the carburetor on a Partner chainsaw
  • How to flush a chainsaw carburetor?
  • Why does the chainsaw stall? Causes and their elimination
  • Troubleshooting
  • fuel mixture.
  • air filter or change it.
  • candle
  • fuel filter
  • carburetor
  • Troubleshooting Walbro
  • Chainsaw service
  • Self disassembly and repair of the carburetor
  • How to clean a chainsaw carburetor?

Need for customization

Chainsaw misalignment is a fairly common occurrence, especially for Stihl and Ural chainsaws. The need is determined in accordance with the presence of the following signs:

  • Instability of motor work. The tool can be hard to start and stall almost immediately, and also not start at all. The root cause is most often a low octane fuel mixture..
  • Significant overconsumption of fuel. Significant exhaust emissions and incomplete fuel consumption can be observed. This situation is typical for the use of highly oversaturated mixtures in Stihl saws.
  • Faults or fluctuations of the coating over the protective caps of the adjusting screws. Such a violation is extremely rare and occurs as a result of inept handling of the adjusting parts..
  • Severe piston wear, briefly corrected by adjustment, but requiring a major overhaul of the chainsaw engine.
  • Carburetor blockages of varying degrees, provoked by the use of low-quality gasoline, as well as malfunctions of the air filter or the ingress of scale. Such a violation requires adjustment in conjunction with high-quality flushing..

Current setting

Experienced operators in the process of work may notice that the internal combustion engine of the chainsaw has begun to work worse. Sometimes it is enough to turn the screws H and L alternately in one direction or another by a small step of 1/5 – 1/6 of a turn and immediately check the result of adjusting the carburetor in real work. This is one of the easy ways to get a good setup..

The video material contains information on how to tune the carburetor of a chainsaw and check the tuning result.

Symptoms of malfunctions and breakdowns in which carburetor adjustment is required.

The following symptoms and malfunctions indicate the need to adjust the carburetor:

  • the engine starts with an effort and stalls almost instantly;
  • gasoline consumption is too high, the exhaust is too thick, the combustible mixture in the cylinder does not completely burn out;
  • the factory settings of the chainsaw carburetor are knocked down (due to vibrations or unsuccessful attempts to regulate);
  • malfunctions of the air cleaning system, which led to the ingress of debris particles into the mechanism for distributing the fuel mixture;
  • significant wear of the piston group – setting the carburetor in this case acts as a temporary measure.

It is clear that if dirt gets into the fuel system with one setting, the problem cannot be solved – it needs flushing. If the piston is worn out, a major overhaul is required. However, in all these cases, the carburetor is also tuned..

What is needed to adjust

To access the adjustment, simply remove the top housing cover and the air filter. Therefore, only a screwdriver for the slots of the adjusting screws is required from the tool..

An electronic tachometer is required for professional carburetor adjustment. It accurately indicates idle and maximum rpm. Idle speed of the Stihl MS 660 chainsaw – 2,500 rpm, maximum – 13,000 rpm.

Without a tachometer, the quality of the carburetor adjustment is determined by ear and by the real operation of the internal combustion engine of the chainsaw.

Chainsaws Partner and Stihl, their adjustments.

In Stihl and Partner chainsaws, the proportion of air and gasoline in the mixture is set with adjusting screws H and L. When the screws are loosened, the mixture is enriched, the speed increases. Screwing in leads to a leaner mixture and, accordingly, a decrease in engine speed.

Setting the carburetor of the partner’s chainsaw to idle is carried out with the T screw (Stihl marks this adjustment with the letters LA). Basic tool setting is done in the factory during final testing. In most cases, the carburetor is adjusted to deliver a slightly richer air-fuel mixture than the optimal design. The factory settings must be saved during the first few hours of operation, during the running-in period. After that, a finer adjustment can be made, although this is not necessary, the saw will work normally on the basic settings..

For fine adjustment of the carburetor, a tachometer is required, in addition, technical documentation will be required in order to carry out work in strict accordance with the manufacturer’s requirements. The best solution would be to entrust the jewelry tuning of the fuel equipment to specialists..

If, nevertheless, it is decided to adjust independently, you should start with the L screw, then go to the H nozzle, and then set the idle speed by rotating the T screw (or LA – if it is a Stihl saw).

By smoothly turning the screw L in both directions, a position is sought at which the idle speed will be maximum. After this point is found, it is required to unscrew the screw L by 1/4 turn. If the chain continues to move when the engine is idling, the T (LA) screw is slowly unscrewed until the chain stops..

After setting the maximum speed with the screw H, the value of their frequency is checked by the tachometer. If the speed at maximum does not correspond to the values ​​indicated in the documentation, the adjustments are repeated. If the mixture is too rich at maximum speed, too much smoke comes out of the muffler, when the mixture is poor, the saw makes a squealing sound and the engine heats up unnecessarily. The adjustment ends by setting the idle speed – the position is considered correct if the engine runs exactly at the minimum speed and the chain is at a standstill. The idle speed setting can be viewed in the video below..

Idle speed adjustment

Carried out with LA screw.

Adjustment is required if the engine stalls at idle – few revolutions, or the chain scrolls – many revolutions.

Reduce RPM by turning screw LA counterclockwise until chain stops, then unscrew back 1 / 5-1 / 4 turn.

Adjustment with screw LA is almost always required after adjusting screw L, which also changes the parameters of the engine at idle.

Screws LA and L regulate idle speed in principle differently. L Changes the quality and quantity of fuel delivery through the calibrated holes. LA is called “booster” because it affects the position of the throttle at idle..

The device and principle of operation of the carburetor chainsaw Stihl MS 660

The carburetor of this model consists of almost 50 parts, including fasteners.

The main nodes of the carburetor of the Stihl MS 660 chainsaw:

  • The body is made of light alloys of non-ferrous metals, with channels for supplying a fuel-air mixture, a storage chamber.
  • Diffuser and chamber in housing for fuel atomization.
  • Nozzles with calibrated holes for metering fuel supply.
  • Air and throttle valves.
  • Needle valve for opening and closing the gas supply channel from the tank.
  • Elastic diaphragm for positioning the needle valve.
  • Manual fuel priming pump for starting a cold engine (primer, or suction).

When you first start a cold chainsaw engine, gasoline is manually pumped up with a primer button. The first jerks of the starter are made with the air damper closed. After setting and during operation of the internal combustion engine, the air damper opens.

During the operation of the internal combustion engine, a vacuum is formed in the combustion chamber, and the mixture is sucked in automatically.

Correct Way To Adjust Or Tune The Carburetor On A Chainsaw – Video

At idle, the flow of the mixture is limited by a closed throttle valve with an opening for a small amount of fuel.

The throttle position is adjusted when the chainsaw is running with the throttle handle. When the handle is pressed, it opens, the fuel supply to the internal combustion engine increases, and vice versa.

On a note! A mixture with low m of gasoline and a large amount of air is called a lean mixture. Conversely, a mixture with more gasoline and less air is called rich..

For normal operation of the internal combustion engine, the mixture must be optimal in terms of the proportions of fuel and air, which is achieved by adjusting the carburetor of the Stihl MS 660 chainsaw.

Husqvarna Saw Carburetor Adjustment.

For the break-in mode, so that the parts receive sufficient lubrication, the carburetor setting of the Husqvarna chainsaw is made so that the maximum speed is 600-700 rpm. below working. If it is not possible to set the operating maximum frequency by the tachometer, you should not change the presets with the H screw. It is forbidden to exceed the value of the maximum number of revolutions by the manufacturer. If, after completing the adjustment, the saw chain moves when the engine is idling, turn the screw T counterclockwise to bring it to a complete stop..

For accurate adjustment, the saw must be warmed up for at least 10 minutes, set on a flat surface. The tire should point away from the person making the tune. At the initial stage, the highest idle frequency should be found. To do this, screw L is smoothly turned first from left to right, then vice versa. When the maximum revolutions are found empirically, screw L should be unscrewed counterclockwise by a value from 1/8 to a quarter of a full revolution.

Idling is adjusted by the nozzle marked with the letter T. It must be turned from left to right until the chain starts to move. Then gently feed in the opposite direction until the rotation of the chain stops. Screw H is considered to be installed correctly if the noise of the saw at full throttle without load remains small. If the exhaust is too smoky and the saw makes a lot of noise, the mixture is too rich. It is necessary to turn the H jet clockwise until the correct sound is set. How to properly tune the carburetor, you can watch the video below..

Stihl 180 chainsaw performance

Model MS180
Engine displacement (ml) 31.8
Max power (hp) 2.0
Max speed (rpm) 14000
Weight (without bar, chain, oil and fuel) (kg) 3.9
Fuel tank volume (ml) 250.0
Oil tank volume (ml) 145.0

Carburetor repair and cleaning without spare parts

There are situations in life in which it is simply vital to repair the saw, but the necessary components are not at hand. For such cases, there is the following method: take out the carburetor, remove the membranes, and then put the rest in acetone and let it soak. Acetone will remove debris that is blocking the passage of various fluids. This method will not hit your pocket, but it is not reliable. Such repairs will not ensure the long operation of the chainsaw, since the outdated membranes have not been replaced..

Checking and subsequent replacement of defective membranes

Stihl 180 chainsaw carburetor membrane repair kit

Characteristics of Stihl chainsaws

Model Working volume (cm 3) Power (kW / hp) Weight, kg) Specific gravity (kW / kg) Standard tire (cm) Standard chain Launch aids Chain tensioner engine’s type
Petrol-powered saws for sawing firewood and for maintenance of the land
MS 170 30.1 1.3 / 1.7 3.9 3.0 35 50 – 3/8 ″ P.1.3 In front 2-stroke
MS 180 31.8 1.5 / 2.0 3.9 2.6 35 50-3 / 8 ″ P-1.3 In front 2-stroke
MS 180 C-BE 31.8 1.5 / 2.0 4.2 2.8 35 50-3 / 8 ″ P-1.3 ErgoStart Fast 2-stroke
MS 181 31.8 1.5 / 2.0 4.3 2.9 35 50-3 / 8 ″ P- 1.3 Lateral 2-MIX
MS 181 C-BE 31.8 1.5 / 2.0 4.6 3.1 35 50-3 / 8 ″ P- 1.3 ErgoStart Fast 2-MIX
MS 192 C-E 30.1 1.3 / 1.8 3.3 2.5 35 50-3 / 8 ″ P-1.3 ErgoStart Lateral 2-stroke
MS 211 35.2 1.7 / 2.3 4.3 2.5 35 50-3 / 8 ″ P-1.3 Lateral 2-MIX
MS 211 C-BE 35.2 1.7 / 2.3 4.6 2.7 35 50-3 / 8 ″ P-1.3 ErgoStart Fast 2-MIX
MS 230 40.2 2.0 / 2.7 4.6 2,3 35 50-3 / 8 ″ P-1.3 In front 2-stroke
MS 231 40.6 2.0 / 2.7 4.9 2.4 35 50-3 / 8 ″ P-1.3 Lateral 2-MIX
MS 250 45.4 2.3 / 3.1 4.6 2.0 35 50-3 / 8 ″ P-1.3 Lateral 2-stroke
MS 250 C-BE 45.4 2.3 / 3.1 4.9 2.2 40 55-3 / 8 ″ P- 1.3 ErgoStart Fast 2-stroke
MS 251 45.6 2.2 / 3.0 4.9 2.2 35 50-3 / 8 ″ P- 1.3 Lateral 2-MIX
MS 271 50.2 2.6 / 3.5 5.6 2.2 37 62-0.325 ″ – 1.6 Lateral 2-MIX
MS 291 55.5 2.8 / 3.8 5.6 2.0 40 67-0.325 ″ – 1.6 Lateral 2-MIX
MS 390 64.1 3.4 / 4.6 5.9 1.7 45 66-3 / 8 ″ – 1.6 Lateral 2-stroke
Petrol saws for forestry
MS 201 35.2 1.8 / 2.4 4.0 2.2 35 50-3 / 8 ″ P- 1.3 Lateral 2-MIX
MS 241 C-M 42.6 2.2 / 3.0 4.7 2.1 40 55-3 / 8 ″ P-1.3 Decompressor Lateral 2-MIX M-Tronik
MS 260 50.2 2.6 / 3.5 4.8 1.8 37 62-0.325 ″ – 1.6 Decompressor Lateral 2-stroke
MS 261 50.2 2.8 / 3.8 5.2 1.9 37 62-0.325 ″ – 1.6 Decompressor Lateral 2-MIX
MS 261-VW 50.2 2.8 / 3.8 5.4 1.9 37 62-0.325 ″ – 1.6 Decompressor Lateral 2-MIX
MS 361 59.0 3.4 / 4.6 5.6 1.6 40 60-3 / 8 ″ -1.6 Decompressor Lateral 2-stroke
MS 362 59.0 3.4 / 4.6 5.9 1.7 40 60-3 / 8 ″ -1.6 Decompressor Lateral 2-MIX
MS 362-VW 59.0 3.4 / 4.6 6.0 1.8 40 60-3 / 8 ″ -1.6 Decompressor Lateral 2-MIX
MS 440 70.7 4.0 / 5.4 6.3 1.6 fifty 72-3 / 8 ″ – 1.6 Decompressor Lateral 2-stroke
MS 440-W 70.7 4.0 / 5.4 6.5 1.6 fifty 72 – 3/8 ″ – 1.6 Decompressor Lateral 2-stroke
MS 441 70.7 4.2 / 5.7 6.6 1.6 45 66-3 / 8 ″ -1.6 Decompressor Lateral 2-MIX
MS 441 C-M 70.7 4.2 / 5.7 6.6 1.6 45 66-3 / 8 ″ -1.6 Decompressor Lateral 2-MIX M-Tronik
MS 660 91.6 5.2 / 7.1 7.3 1.4 fifty 72-3 / 8 ″ -1.6 Decompressor Lateral 2-stroke
MS 880 121.6 6.4 / 8.7 9.8 1.5 90 108-0.404 ″ -1.6 Decompressor Lateral 2-stroke
Special saws
MS 150 TC-E 23.6 1.0 / 1.3 2.6 2.6 thirty 64 – 1/4 ″ P – 1.1 ErgoStart Lateral 2-MIX
MS 192 T 30.1 1.3 / 1.8 3.1 2.4 thirty 44-3 / 8 ″ P-1.1 Lateral 2-stroke
MS 201 T 35.2 1.8 / 2.4 3.7 2.1 35 50-3 / 8 ″ P-1.3 Lateral 2-MIX
MS 192 C-E Carving 30.1 1.3 / 1.8 3.3 2.5 thirty 64- 1/4 ″ P- 1.3 ErgoStart Lateral 2-stroke
saws
MSE 160 C-BQ 1.6 4.1 35 50-3 / 8 ″ P-1.3 Fast
MSE 180 C-BQ 1.8 4.2 40 55-3 / 8 ″ P-1.3 Fast
MSE 220 C-Q 2.2 6.2 45 66 – 3/8 ″ – 1.6 Lateral

Stihl 180 chainsaw carburetor tuning

Repair and adjustment of the carburetor of the Stihl 180 chainsaw

The Stihl 180 is a German chainsaw designed for gardening, logging, site clearing and other woodworking. Many people love it for its compactness and ease of use. The instrument combines seemingly opposite qualities – power and maneuverability. German designers have tried to create this sample, but the MS 180 Stihl also has drawbacks that users face in various operating modes. Like all mechanisms, it tends to fail. What to do in such cases and is it worth contacting the workshops?

The main stages of work (removal of the carburetor)

The best option would be to watch a training video. Fortunately, there are dozens of them on the Internet. There they will tell you everything in detail and professionally. As the saying goes: “It is better to see once than hear a hundred times” (in our case, read it). Schematically, this process can be written as follows: remove the protective cover, remove the rods and, finally, unscrew the unit to work with it.

Common malfunctions of the Stihl 180 carburetor

Malfunctions that can be solved by repairing the carburetor: It is worth noting that diagnostics may not always correctly indicate the problem. There are times when, due to different reasons, the same “symptom” occurs. And sometimes diagnostics can give false information, as a result of which you will not be able to correctly eliminate the cause of the breakdown. Pay due attention to diagnostics, but do not overestimate its importance..

The tool does not hold idle revolutions, and sometimes the revolutions “walk”. Most likely the idle jet is clogged. It is urgent to clean it, otherwise the saw will not be able to perform its functions. Another possible cause is a malfunction of the fuel system..

Sometimes this problem is solved by unclogging the valve that restricts the fuel tank. This valve regulates the output of gasoline and the passage of air. Do not forget to adjust the carburetor by changing the amount of air that is supplied to it. More details about this operation can be found in the instructions included with the brand new chainsaw..

The carburetor of the Stihl chainsaw, without disassembling, can only be adjusted for the number of revolutions produced at idle. It is impossible to increase or decrease the fuel supply in various modes. Manufacturers have limited access to this adjustment by removing special screws. If faults are found in this system, it is possible, with experience, to increase the gap between the needle valve and the wall.
The saw does not start. The solution is the same as in the previous paragraph.

The tool began to consume more fuel, while its power was significantly reduced. Gasoline consumption and power are subjective concepts. To accurately determine these indicators, you can not do without visiting special firms specializing in this tool..

Well, if these two indicators are visible “on the face”, then follow these steps:

Check if the chain is dull. A dull chain has a lower efficiency, and therefore the saw consumes more fuel.

Examine the fuel tank. Perhaps it has formed small mechanical damage, through which gasoline leaves imperceptibly..

Examine the muffler carefully.

Clean the cooling system and exhaust system.

The unit stalls immediately after operation or warming up. Experts call it hot.

The most common reasons are:

  • Lack of air entering the carburetor. Replace inlet and outlet valves.
  • Breakdown of the cooling system (overheating). It is possible that foreign objects have entered the pipes with cold air, which will need to be removed..
  • Chainsaw stalls when position is changed. This only applies to tilting to the side, in the vertical state the saw functions normally. This problem even applies to serviceable chainsaws, because during the development the designers made a small mistake. The Stihl 180 fuel system has a special design, in which the fuel cannot escape from the tank on its side. Sometimes the problem lies in the clogging of the fuel pump.

The procedure for parsing, as well as tuning the carburetor of the Stihl 180 chainsaw: In order to carry out a high-quality repair of the carburetor, you will need to remove it. This is not difficult to do, but you need to be extremely careful. To begin with, we will prepare the workplace: install the lighting, lay out all the necessary tools. Understand that the carburetor is the main saw unit where the fuel and gasoline flows intersect. For stable operation, they must be cleaned of foreign debris..

Therefore, before the main work, you need to do the following:

  • Remove and clean the muffler.
  • Make sure that there are no problems with the supply and combustion of fuel.
  • Check the serviceability of the air and cooling filters.