The situation when the gasoline trimmer starts, but immediately stops, is familiar to many owners of garden equipment. This is a classic symptom of the imbalance between the fuel supply and the air supply to the combustion chamber. The engine starts on the remnants of the mixture but does not receive enough power to maintain stable rpm, resulting in an immediate stop.
In most cases, the problem lies not in a serious engine failure, but in clogs of the fuel system or a violation of the tightness of the air sucker. carburetor It is the heart of the system, and even microscopic dirt can disrupt it. Often owners panic, thinking about overhaul, although it is enough to conduct a competent diagnosis of fuel supply units.
Before disassembling complex nodes, it is worth checking the elementary things: the quality of gasoline, the condition of the air filter and the presence of a spark. It is with these simple steps that the professional diagnosis of any motor vehicle begins. If the fuel is fresh and there is a spark, then the problem lies deeper in the mixing system.
Poor quality fuel and problems with the supply of mixture
The most common, but common, reason for trimmer It is deficient immediately after launch, and there is poor fuel. Gasoline tends to oxidize and lose its properties during long-term storage, especially if oil for two-stroke engines is added to it. This mixture is layered, and the combustion chamber gets either pure oil or old gasoline, which does not allow the engine to work stably.
If you use fuel that has been in the canister for more than a month, it is better to drain it. Octane number Also plays a role: the use of gasoline with an octane number below the manufacturer's recommended (usually an AI-92 or AI-95) can cause the engine to detonate and stop. Always check the ratios of mixing oil and gasoline, as excess oil leads to the coking of candles.
The second aspect is the physical impossibility of supplying fuel to the carburetor. A vacuum can form in the fuel tank if a hole in the lid is clogged, or the fuel filter inside the tank is clogged with dirt. As a result, gasoline simply does not reach the engine in the desired volume.
⚠️ Warning: Never leave the fuel mixture in the trimmer tank for storage for more than 2 weeks. This is guaranteed to lead to clogging of the carburetor with resinous deposits and require complex washing.
To check the fuel supply system, you can disconnect the hose from the carburetor and check whether the gasoline flows automatically when the valve is open (if any) or simply when tilting. If the jet is weak or intermittent, the problem is in the filter or hose.
- ⛽ Use only fresh fuel mixtures made no more than 2 weeks ago.
- 🛢️ Follow the exact proportions of oil and gasoline specified in the instructions for chainsaw Or a trimmer.
- 🧹 Change the fuel filter mesh inside the tank regularly if it is contaminated.
Flooding of fuel filter and highways
If the fuel quality is in order, attention should be switched to filter elements. The fuel filter, located at the end of the hose inside the tank, serves as the first line of defense against debris. Over time, it is clogged with fine chips, dust or resins, which creates resistance to the flow of liquid. The engine consumes fuel, the filter does not have time to pass it, the highway is formed by a vacuum, and the engine dies.
Check the condition of the filter by pulling it out through the neck of the tank. If it has a dark color or sticky structure, it must be replaced. It is also worth examining the fuel hose itself: it should not have cracks, claps or swelling from the aggressive effects of modern gasoline with additives.
Water is heavier than gasoline and accumulates at the bottom, from where the fuel is taken. Even a drop of water entering the combustion chamber causes an instantaneous stop of the engine.
When removing the fuel hose from the tank, use a thin wire with a hook at the end - this will simplify the task if the hose has gone deep inside the container.
Cleaning highways often solves the problem of starvation of the engine. Blowing the hoses with compressed air helps to remove small obstacles, but if the hose has lost elasticity, it is better to replace it entirely to avoid air suction.
Carburetor malfunctions: adjustment and cleaning
The most common and difficult cause of job instability is carburetor. This is where the air and fuel mix. If the trimmer starts and stalls, most likely, the idling settings are violated or the jeepers are clogged. The membrane of the carburetor could coarse or lose elasticity, which is why it stops pumping fuel correctly.
Cleaning the carburetor requires care. It is necessary to remove the node, disassemble it and wash all channels with a special cleaner (carbkliner). Particular attention is paid to the mesh filter and needle valve. Any motley in the jellyclera hole can disrupt the entire process of mixing.
The secret of setting up the carburetor
Many carburetors have three adjustment screws: L (low revs), H (high revs) and T (idle). The screw L is responsible for the engine's reception at start-up and set of revolutions. If the trimmer dies when pressing the gas, most likely, the mixture is too poor and the L screw needs to be twisted out a little (counterclockwise).
After assembly and installation of the carburetor, it is often required to adjust it. The idle screw (usually denoted by the letter T or LA) is responsible for the position of the throttle. If it is twisted too hard, the valve is closed, and the engine does not have enough air to work on idles. If twisted, the engine may stall due to the re-enrichment of the mixture.
| Symptoms. | Possible cause in a carburetor | Elimination method |
|---|---|---|
| Deaf to singles | Idle channel clogged | Blowing and cleaning of canals |
| It's gas-deaf. | Too poor mixture (L screw) | Adjustment of the mix quality screw |
| It only works with the suction. | Leaky or clogged | Replacement of pads, cleaning |
| Unstable turnovers | Membrane damaged. | Replacement of the carburettor remake |
Air filter and suction of extraneous air
Air is needed to burn fuel. If air-filter clogged with grass dust, down or dirt, the engine begins to "choke". The mixture becomes over-enriched (lots of gasoline, little air), which leads to black soak on the candle and the engine stops. Checking the filter is the first thing to do if the trimmer has lost power.
However, there is also the reverse, more dangerous problem - sucking unaccounted air. This occurs when the tightness of the connection of the carburetor and cylinder is broken, or when the crankshaft oil has cracked. The engine begins to suck air through the cracks, bypassing the carburetor. The mixture becomes too poor, the temperature in the cylinder rises, and the motor stalls, often with a characteristic whistle.
Check the tightness can be visually, inspecting the gaskets and glands for cracks. A more accurate method is to use a smoke generator or spray a running WD-40 engine in the places of the proposed sucker. If the revolutions begin to change, then the liquid entered the combustion chamber through the slit.
- 🌬️ Remove the air filter and try to start the trimmer (shortly). If the work is stabilized, the filter is replaced.
- 🔍 Examine the gasket between the carburetor and the cylinder for tears.
- 🛠️ Check the tightening of the carburetor mount bolts, they could weaken from vibration.
⚠️ Note: Operation of the trimmer without an air filter is strictly prohibited. Abrasive dust entering the cylinder causes accelerated wear of the piston group ("bullyers"), leading to expensive repairs.
Ignition system and candle
Although the problem is more often in the fuel, the ignition system cannot be excluded. If spark-plate covered with black soda, this indicates a rich mixture or poor-quality oil. A wet candle does not give a spark, and the engine dies. If the candle is dry and white - the mixture is too poor, overheating is possible.
It is important to check the gap of the candle. It must meet the specification (usually 0.6–0.7 mm). Too much gap requires high voltage, which the coil may not give out, especially at high revs. It is also worth checking the state of the high-voltage wire and cap: oxidation of the contacts leads to an unstable spark.
Sometimes the cause is wrong. gap between the coil's magnetic wire and the flywheel. If it is too large, the spark will be weak or disappear when the engine is heated. To adjust this gap, a sheet of paper or a special probe is used, laid between the coil and the flywheel magnet.
☑️ Diagnosis of spark plug
Tanks and ventilation system
Few people know that in the fuel tank lid there is a small hole or valve - a sapoon. It is necessary to equalize the pressure. When the fuel is consumed, a vacuum is created in the tank. If the sapoon is clogged, the vacuum becomes so strong that the carburetor fuel pump cannot overcome the resistance and stops pumping gasoline. Trimmer is working on the remnants in the float chamber and is deaf.
The symptom is simple: the trimmer works for a few minutes, then stalls. If you immediately unscrew the tank lid, you hear the characteristic sound of the intake air ("psh"), and the engine starts again and works for a while. This is a sure sign of a sapuna malfunction.
The solution to the problem is elementary: clean the hole in the lid with a thin wire or needle. In some models, the lids are made in the form of a separate valve, which can be washed in gasoline or replaced.
If the trimmer stops at regular intervals and starts again only after opening the tank lid - a problem 100% in the fuel tank sapuna.
Silencer and exhaust system
The exhaust system also needs attention. In the silencer of the two-stroke engine, the swelling from the combustion of oil accumulates over time. If the exhaust channels are clogged with combustion products, the gases will not have time to leave the cylinder. This creates back pressure that suffocates the engine. Trimmer starts, but stalls under load or even on singles.
To check, it is necessary to remove the muffler and inspect the cylinder outlet. If thick smoke with sparks falls from the pipe when working, and the power has fallen, the muffler needs to be cleaned. It can be burned on an open fire (propane burner) or soaked in special chemical solvents.
It is important not to confuse the symptoms: if the muffler is clogged tightly, the engine may not start at all. But partial blockage just gives the effect of "starts and stops", especially when trying to add gas.
The myth of the leaky silencer
Some "craftsmen" advise drilling a hole in the muffler to improve traction. You can't do that! This violates the acoustic resonance of the release, increases noise and the emission of harmful substances, and can also lead to a burnout of the piston due to a violation of the purge.
Frequent questions about trimmer malfunctions (FAQ)
Why does the trimmer stop when you give it to the gas?
Most often, this indicates that the engine does not receive enough fuel when opening the throttle. Causes: clogged fuel filter, clogged high-speed jet lacquer in the carburetor, or disturbed adjustment of the screw quality mixture (L). It is also possible to suck air through the gums.
The trimmer is started only with a closed valve (suction) and deafens when you open. What's up?
This is a classic sign that the engine is getting too little fuel (poor mixture) or sucked excess air. When the valve is closed, the dilution is high and the fuel leaks out. When the valve is opened, the dilution drops, and there is not enough fuel. Check the carburetor for tightness and cleanliness.
How often should I change the fuel filter in the trimmer?
It is recommended to check the condition of the filter every season. If you use the equipment professionally, it is better to make a replacement once a year or every 50 motor hours. Visually, the filter should be light, without oily plaque and dirt.
Can the trimmer become deaf due to overheating?
Yes, if the cooling is disturbed (the cylinder ribs are clogged with grass) or the poor mixture works. When overheated, the piston expands, jams in the cylinder, and the engine stops. After cooling, it can work again, but this will cause serious damage.
What if the trimmer does not keep blanks after winter?
Most likely, during the winter, the light fraction of gasoline evaporated, and a sticky sediment remained in the carburetor. It is necessary to wash the carburetor, replace the fuel filter and pour fresh mixture. Often helps simple cleaning and adjustment of the idle screw.