After prolonged downtime or sharp cooling, the Chinese chainsaw stops running due to a violation of the proportions of the fuel mixture or bay. spark-plug liquid gasoline. In most cases, the problem lies in the absence of a spark or overlap in the fuel supply to the cylinder, which requires an immediate check of the ignition system and cleaning of the fuel channels from resinous deposits. Ignoring primary symptoms, such as a heavy start or loss of power, often leads to more severe piston group breakdowns requiring costly replacement of nodes.
Diagnosis should begin with a visual examination and check for the presence of a spark, since it is precisely the presence of a spark. ignition Chinese saws often fail due to moisture or breakdown. If there is a spark, but the engine is silent, you need to make sure that the cylinder receives fuel and is not disturbed. compression. Often, owners forget to open the air valve after warming up or use poor-quality gasoline, which makes it impossible to start without a complete wash of the system.
Modern Chinese assemblies, such as Husqvarna-like models or brands like Partner and Stihl (Chinese assembly), sensitive to the quality of the assembly and settings of the carburetor. The lack of factory adjustment or downed screws of quality of the mixture can completely block the operation of the engine. It is important to consistently exclude each of the possible causes, moving from simple checks to complex repairs, so as not to waste time disassembling serviceable nodes.
Problems with the ignition system and candle
The first step in the absence of a start is to twist the spark plug. If you find that it is wet and smells of gasoline, it indicates that it is a good idea. re-enrichment Or engine bay. A dry candle, on the other hand, indicates that fuel is not entering the cylinder and the problem lies in the fuel system or carburetor. The color of the soda is also important: black and loose speaks of a rich mixture, and white or light gray - about poor, which is dangerous overheating.
⚠️ Note: When checking the spark, do not hold the candle in your hands without insulation, as the discharge of a high-voltage pulse can be tangible and unpleasant. It is better to press the threaded part to the metal part of the cylinder through a dielectric or use a special tester.
Lack of spark is often associated with malfunction magneto Or ignition coils. The gap between the magnetic conductor of the coil and the flywheel should be strictly within 0.2-0.3 mm. Too large a gap will lead to weak spark formation, and too small - to damage to the coil during the rotation of the flywheel. In Chinese saws, there is often a marriage of the ignition module itself, which cannot withstand vibrations.
It is also worth checking the condition of the high-voltage cap. If it is oxidized or has cracks, the current will go to the mass, especially in wet weather. Contact line It should be dense and clean. Sometimes it helps to simply clean the contacts and wipe the surface of the cap with a solvent, but in the presence of insulation breakdowns, a complete replacement of the element is required.
- 🔌 Check the gap of the candle (should be 0.6-0.7 mm) and the integrity of the central electrode.
- 🔥 Make sure there is a powerful blue spark when scrolling the starter.
- 🧹 Clean the candles with calcination or mechanically if the electrodes are intact.
- 🔧 Check the reliability of the cap fixation on the high-voltage wire.
Failures of the carburetor and fuel system
If the spark is all right, the next suspect becomes the carburetor. Chinese models are often equipped with membrane carburetors, sensitive to fuel quality. Old gasoline, left in the tank for more than 2-3 weeks, is oxidized and turns into a resinous substance that clogs the chicklers and channels. In this case, the saw has to be completely disassembled and washed with ultrasound or special cleaners.
It is also important to check the fuel filter inside the tank. If it is contaminated or disconnected from the hose, gasoline simply will not flow into the carburetor in the required amount. Hoses of fuel supply should be elastic; if they are cocked or cracked, air sucking occurs, which disrupts the work. fuel mixture. Hermeticity is a key factor in stable work.
Adjustment of the carburetor is carried out by three screws: L (low revs), H (high revs) and T (idle). Incorrectly configuring the L screw can make it impossible to start the engine, as the mixture will be too poor or too rich to start. On Chinese saws factory settings are often knocked down, and fine adjustment is required "by ear" for the engine.
☑️ Diagnostics of the fuel system
Particular attention should be paid to the paging membrane. If it has lost elasticity or ruptured, the carburetor will not be able to pump fuel. This is a common problem with budget models where low quality materials are used. Replacing the carburettor remake usually solves the problem, but requires careful assembly.
Air suction and engine compression
Lack of launch could be caused by critical fall compression in the cylinder. For two-stroke engines of Chinese chainsaws, pressure in the range of 8-12 atmospheres is considered normal. If the compression is below 6 atmospheres, the engine will most likely not start or will work extremely unstable. Checking is best carried out by a compressometer screwed in instead of a candle.
The cause of loss of compression is often wear of the piston group or damage to the crankshaft coils. Suction of air through the glands leads to impoverishment of the mixture and overheating, which eventually causes bullies on the piston and cylinder. The tank sapoon can also be clogged, creating a vacuum in the tank that prevents fuel from flowing into the carburetor.
⚠️ Note: Operation of the saw with impaired tightness of the crankcase or air sucker is strictly prohibited, as this leads to rapid destruction of the piston group due to work on a poor mixture and overheating.
Check the tightness of the crank-shaking mechanism can be done using a special device for pressing or smoke test. Pressure air into the candle hole and immersion of the engine in water (or washing joints) allows you to detect leaks. Air bubbles will indicate the place of depressurization: glands, gaskets or crankcase cracks.
- 📉 Measure compression with a compressometer (normal from 8 atm).
- 🌬 Check the fuel tank sapoon for clogging.
- 🔍 Examine the space around the cylinder for oil leaks.
- 🛠 Test for the tightness of the crankshaft coils.
Air filter and silencer
Scored air-filter One of the most common and easily remedied causes of launch problems. If the filter is soaked in oil and dust, the engine “chokes” and gets too little air. As a result, the mixture becomes over-enriched, the candle is flooded, and the launch becomes impossible. Regular cleaning or replacement of the filter is a mandatory maintenance procedure.
Equally important is the condition of the silencer. In two-stroke engines, the products of oil combustion settle in the exhaust system, forming a dense soda. Over time, the muffler outlet can become completely overgrown, creating a backpressure that prevents gases from exiting the cylinder. The engine in this state can sneeze once and not start again.
How to Clean a Silencer from Scoop
Remove the muffler from the engine. Place it in a container of kerosene or special chemistry to remove the sodium for a few hours. After soaking, clean the inner cavities with a metal brush and blow with compressed air. Make sure that the sparkler net (if any) is also cleaned.
To check, remove the air filter and try running the saw without it (shortly). If the launch is improved, the problem is in the filter. Similarly, you can remove the muffler and close the exhaust hole with cardboard, scrolling the starter: if the cardboard is knocked out with force, the exhaust system is free. If not, you need to clean or replace the muffler.
Table of diagnostics of major malfunctions
To systematize the search for malfunction, use the following table, which links the symptoms with probable causes. This will help to quickly determine the direction of repair and avoid unnecessary actions.
| Symptoms. | Probable cause | Action. |
|---|---|---|
| Candle wet, spark there | Engine flooded, ignition interruptions | Dry the cylinder, check the gap of the candle |
| Candle dry, spark is | No fuel supply. | Check the filter, hoses, carburetor |
| Sparkle is missing | Magneto or cap malfunctioning | Replace the ignition module or wire |
| Low compression. | Depreciation of CPG or galls | Engine defect, replacement of rings/piston |
| The saw starts and dies. | Sapoon or jelly-clogged | Clean the tank sapoon and carburetor channels |
Use only fresh fuel mixture (AI-92 petrol + oil for 2T engines) in the ratio of 1:25 or 1:40, specified in the instructions. Mixtures older than 2 weeks can not be used!
Seasonal problems and operating conditions
In the cold season, Chinese chainsaws may not start due to condensation in the carburetor or freezing moisture in the fuel system. If the saw is stored in an unheated garage, temperature changes contribute to the formation of water inside the tank. Water is heavier than gasoline and accumulates at the bottom, getting into the carburetor first and blocking the engine.
In summer, the problem can be reversed – engine overheating due to poor mixing or contamination of cylinder cooling ribs. Air cooling It requires clean surfaces. If the cylinder ribs are clogged with sawdust and grass, heat transfer is disrupted, the engine wedges or loses power, making it difficult to restart after stopping.
⚠️ Warning: Never try to start a chainsaw if you smell a strong smell of gasoline around it. This can lead to a flare-up of vapors and a fire. First, ventilate the room and eliminate the cause of the leak.
It is also worth considering the quality of the assembly of a particular model. Chinese manufacturers often save on gaskets and seals. Before the start of the season, it is recommended to conduct a preventive examination of all seals. Replacing cheap rubber elements with better quality analogues (for example, from branded saws) can significantly extend the life of the tool.
- ❄️ In winter, keep the saw warm or drain the fuel completely.
- 🌡 Watch the engine temperature, do not overheat.
- 🧹 Regularly clean the cylinder ribs from debris and dust.
- 🛢 Change the fuel hoses once a season if they lose their elasticity.
80% of the problems with the launch of Chinese chainsaws are solved by replacing a candle, cleaning the carburetor and using a fresh fuel mixture.
Frequent errors in start-up and maintenance
Many users make common mistakes that mimic a breakdown. For example, forgetting to open the choke after the engine warms up (forgetting to open the valve after warming up) or, conversely, not closing it when starting cold. The launch algorithm is broken, and it seems that the saw is faulty.
Another mistake is to use pure gasoline without oil. In two-stroke engines, oil is mixed with lubrication fuel. Working on pure gasoline leads to an instantaneous piston slack and engine jamming. After such an error, the saw will not start until a major repair is carried out.
The Right Launch Algorithm
1. Turn on the ignition. 2. Close the air valve (lever in position closed). 3. Press the decompressor (if any). 4. Pull the starter to the first sneeze. 5. Open the damper. 6. Start the engine.
Incorrect adjustment of the carburetor "for rich" mixture also harms. The engine works loudly, smokes, the candle turns black, but it can be difficult to start it with such a setting. Balance is required: the engine must confidently gain momentum without failures. If you are not confident in your abilities, it is better to consult a specialist for initial setting.
Why does the chainsaw start only when the valve is closed?
This is a classic sign that the engine is not getting enough fuel through the regular channels of the carburetor at idle speeds. Most likely, clogged idle jikler or there is an air sucker. With a closed valve, a greater depression is created, and the fuel begins to flow, but it is impossible to work in this mode constantly - this will lead to overheating.
Can I use gasoline for a Chinese saw?
Only gasoline with an AI-92 octane number can be used. AI-95 and AI-98 contain additives that can be aggressive to the membranes of the carburetor and the oils of cheap Chinese saws. In addition, high octane does not provide advantages in engines with a low compression ratio.
How often should the fuel filter be changed?
The fuel filter is recommended to be changed every season or with each replacement of fuel hoses. If you notice that the filter has turned black or has become sticky, replace it immediately. The cost of the filter is low, and the consequences of its tearing off or clogging can be serious.
What if you don’t drink after winter?
There is probably some old fuel in the carburetor. It is necessary to drain the remnants from the tank, twist the candle, blow the cylinder (pull the starter several times), pour a fresh mixture and try to start. If it doesn’t work, you’ll need to clean the carburetor.