The situation when a powerful German equipment suddenly loses traction, catches any owner by surprise. Chainsaw Stile does not develop turnovers under load most often due to a violation of the proportions of the fuel mixture or clogging of the filter elements. An internal combustion engine requires an ideal balance of air and fuel to create a powerful explosion in the cylinder.
If during idling, the tool works stably, but when in contact with wood begins to wither, deafen or simply stops sawing, then the combustion process is disrupted. Two-stroke Stihl engine It is particularly sensitive to oil quality and airflow purity. Ignoring the first symptoms can lead to major repairs of the piston group.
In this article, we will discuss in detail the mechanical and chemical causes of power drop. You will learn to diagnose malfunctions of the carburetor, silencer and ignition system without contacting the service center. Right. diagnostics It'll save you money and time.
Testing of fuel system and mixture quality
The most common but common reason is old fuel. Gasoline with an octane number of 92 or 95 has a limited shelf life, especially when mixed with oil. If a mixture prepared a month ago is splashed in the tank, it loses its flammable properties. The engine simply cannot get the energy to spin the circuit under the pressure of wood.
The second critical point is the mixing proportion. For modern saws Stihl MS 180, MS 250 The ratio of professional models is usually 1:50 (20 ml of oil per 1 liter of gasoline). Excess oil leads to coking of the piston and candle channel, and the lack - to overheating and bullying. In both cases engine falls.
Use only special synthetic oils for two-stroke engines labeled JASO FD or ISO EGD. Conventional motor oil for cars is categorically not suitable and will quickly disable the saw.
The fuel filter also plays the role of a limiter. If it is clogged with mud or tar deposits, gasoline enters the carburetor in jerks. With idling, fuel is enough, but when the throttle is opened, fuel starvation occurs. The saw begins to "choke" and reset.
Diagnostics of air filter and air supply
For proper mixing, the volume of incoming air is critically important. If air-filter clogged with fine wood dust, the engine starts to work on an enriched mixture. This leads to the formation of black soda on the candle and a decrease in the efficiency of combustion.
Owners often think that the filter looks clean, but the microscopic pores are already clogged with oily dust. Washing the filter in gasoline or a specialized solution helps restore its throughput. However, if the filter is damaged or deformed, it must be replaced.
Check the integrity of the air channel between the filter and the carburetor. Cracks in the pipe or loose fit of the filter cover lead to the sucking of unfiltered air. This violates the calculated parameters of the carburetor, and the saw ceases to pull.
Carburetor malfunctions and screw adjustment
The carburetor is the heart of the chainsaw. If Chainsaw Stile does not develop turnoverThe L, H and T screw settings may have been lost. The H screw is responsible for maximum revs and power under load. If it is twisted too hard, the mixture becomes poor (low fuel), which is dangerous for the piston. If twisted - the mixture is rich, the saw "choked".
A common problem is needle wear or clogging of jellyplants. Garbage from the tank can get into the channels of the carburetor, blocking the fuel supply when sharply pressing the gas. It is also worth checking the tightness of the pads. Sucking air through the gasket of the carburetor is a classic cause of unstable work.
☑️ Diagnosis of the carburetor
A tachometer is needed for precise setting. To put the correct turns under load is almost impossible. Factory parameters for different models Stihl They are different, and arbitrary adjustment can lead to overheating.
Contamination of muffler and exhaust system
One of the most overlooked causes of power loss is a clogged muffler. In the process of working on the walls of the sparker and exhaust channel, scorching accumulates. Over time, this layer becomes so thick that it begins to strangle the engine. The exhaust gases have nowhere to go, and they prevent the entry of a new portion of the mixture.
The symptoms are the same as with fuel starvation: the saw works on singles, but deafens when sawing. If you remove the muffler and find that the exit holes are completely covered with a black crust, the problem is solved. Mechanical cleaning or burning of the sodium returns the tool a second life.
⚠️ Note: When cleaning the silencer, use a respirator. Nagar contains carcinogenic substances and asbestos fibers (in older models), which are extremely dangerous to the lungs when inhaled.
Also check the condition of the squirrel mesh. If it is melted or clogged, the exhaust resistance increases many times over. In some cases, it is easier to replace the muffler whole than to try to clean it of a dense layer of coke.
Ignition system and candle condition
The spark plug is an indicator of engine health. Turn it off and carefully examine the color of the garlic. Brick brown color indicates the right work. Black, shaggy soda indicates a rich mixture or poor oil. White plaque is a sign of working on a poor mixture and the risk of overheating.
The gap between the electrodes is also important. Over time, it can increase, which requires a higher voltage to break the spark. The ignition module (coil) may not cope with the load, especially when heated. The spark becomes weak, and the ignition of the mixture under the pressure of the piston occurs with a delay or does not occur at all.
Check the high-voltage wire. If the insulation is damaged, the spark can "pierce" the engine body, especially in wet weather. This leads to interruptions in operation and loss of power.
How to check the spark correctly?
Unscrew the candle, put a cap on it and press the thread to the metal part of the cylinder (mass). Pull the starter. The spark should be bright blue and punch the gap with a loud crack. An orange or yellow spark indicates problems with the module or wire.
Mechanical problems: compression and osteomy
If all systems are normal, but chainsaw's not pullingThe problem may lie in the piston group itself. Wear of the cylinder-piston group (CPG) leads to a drop in compression. The engine cannot create enough pressure to compress the mixture effectively.
Another hidden problem is the crankshaft. If they are dried or damaged, air sucking into the crankcase begins. This disrupts the discharge required to suck fuel out of the tank. The saw is working in jerks and does not keep pace.
| Symptoms. | Probable cause | Action. |
|---|---|---|
| It's deaf when you press the gas. | Fuel filter or muffler clogged | Replace the filter, clean the muffler |
| It only works on the suction. | Sucking air through a carburetor or glands | Check the tightness, replace the gums |
| Heats up and loses power. | Poor mixture (H screw) | Enrich the mixture, check the filter |
| Black smoke from the silencer | Excess oil in the mix | Fuse the fuel, prepare a new mixture |
A compression drop below 8 atmospheres makes the chainsaw impossible to function normally. Measure the compression with a compressometer through the candle hole.
Frequent errors in service
Many users try to solve the problem of power loss by rough adjustment of the carburetor, twisting the screws to the point. This leads to the operation of the engine at the limit of possibilities, which reduces its resource at times. Instrumental accuracy more important than intuitive guesses.
The use of low-quality gasoline with a high alcohol or water content is also harmful. Water does not burn, but turns into steam, which breaks the oil film. This causes instant wear of the rubbing pairs and jamming of the piston.
⚠️ Warning: Never store the prepared fuel mixture for longer than 2-3 weeks. The old mixture is oxidized, precipitates and loses its octane number, which directly affects the power of the saw.
FAQ: Frequently Asked Questions
Why does the saw of Still die when you start sawing a thick log?
Most likely, a muffler or fuel filter is clogged. The engine does not have enough fuel to maintain the speed under increased load, or the exhaust gases do not have time to go out. Also check the sharpness of the chain – the dull chain creates excessive resistance.
Can the power of the saw be increased by adjusting the carburetor?
Theoretically, it is possible to enrich the mixture, but this will lead to overheating and a decrease in the engine life. Factory settings are the optimal balance between power and durability. Increased power is possible only by replacing the piston model with a large volume.
How often should you clean the carburetor on a chainsaw?
Preventive cleaning is recommended once a season or after 50 fuel tanks have been produced. If you use quality oil and good gasoline, a carburetor may not require intervention for years.
What if after cleaning the muffler, the saw still does not pull?
It is necessary to check the compression and tightness of the crankshaft coils. If the compression is normal, the problem may be in the ignition module, which loses the spark power when heated.