The gasoline trimmer stops starting on a cold one most often due to improper adjustment of the carburetor, clogging of the fuel filter or violation of the tightness of the fuel system, which leads to dilution of the mixture at start-up. Instead of a confident start, the engine only briefly “captures” or completely ignores the jerks of the starter, requiring an immediate check of the state of the spark plug and the quality of the fuel mixture, since ignoring these symptoms can lead to more serious damage to the piston group.
The cold start of the internal combustion engine is always a stress for the mechanism, since the oil has not yet been distributed to all the nodes, and the temperature of the parts is far from working. If the wrong adjustment of the valve or old gasoline is added to this, it becomes almost impossible to start the unit. In this article, we will discuss the main reasons why trimmer is not well started on coldWe will provide a step-by-step algorithm of actions to restore the device to work.
Fuel mix quality and gasoline condition
The most common reason why gas-cot Refusing to start, is the use of poor quality or old fuel. Gasoline tends to oxidize and lose its properties during long-term storage, especially if the tank has a mixture of oil and gasoline. After 2-3 weeks, such a “cocktail” turns into a viscous substance that clogs the jelly carburetor and does not allow the engine to get the necessary portion of energy for start.
In addition, it is critical to follow the correct mixing proportions of gasoline with two-stroke oil. If you use a mixture with excess oil, the engine will “choke” and smoke, and the candle will quickly be covered with black soda. With a lack of oil, there is a risk of a bully of the piston group due to overheating. For most modern trimmers, such as Stihl or HusqvarnaThe optimal ratio is 1:50, but older Chinese-made models may require 1:25 or 1:33.
⚠️ Attention: Never store the prepared fuel mixture for more than one month. Old gasoline loses its octane number, which leads to detonation and difficulty starting the engine to cold.
To check the quality of fuel, you can twist the candle and inspect its electrode. If it is wet and smells stale gasoline, then the problem is in the supply of poor-quality mixture. In this case, you need to completely drain the contents of the tank, wash the fuel filter and pour fresh AI-92 or AI-95 gasoline with high-quality synthetic oil for two-stroke engines.
Use only fresh gasoline purchased no more than 2 weeks ago. To store fuel, use special canisters made of opaque plastic or metal to avoid sunlight and condensation.
Ignition system: candle and high-voltage wire
If the fuel is in order, the next candidate for testing is the ignition system. Ignition candle It is an indicator of engine health. Its appearance can tell an experienced master a lot: black dry soda will indicate a re-enriched mixture, white plaque - overheating or poor mixture, and oily plaque indicates the oil entering the combustion chamber through the coils.
Often the reason that the trimmer does not start is the lack of a spark. This can happen due to a breakdown of the high-voltage wire, a faulty ignition coil or simply contamination of the candle. To check for the presence of a spark, you need to twist the candle, put a cap on it, attach the metal part of the candle to the engine body (mass) and pull the starter. A bright blue spark indicates the serviceability of the system, a weak reddish or its absence requires replacement of elements.
- 🔍 Candle gap: Check the distance between the electrodes, it should be 0.6-0.7 mm for most trimmer models.
- 🧹 Cleaning: If the candle is wet, dry it and calcinate it over the fire to remove any remaining fuel.
- 🔌 Contact: Make sure the cap sits tightly on the candle and has no cracks through which the voltage can escape.
It is also important to check the gap between the magnetic wire of the coil and the flywheel. If it is too large, the spark will be weak or not appear at all. Adjustment of this gap is made with the help of a business card or a special probe, usually it is about 0.2-0.4 mm. The wrong gap is a common reason why chinese trimmer It stops immediately after launch or does not start at all.
Carburetor: adjustment and cleaning
The carburetor is the heart of the fuel system, and it is its malfunction that most often leads to cold start problems. If the trimmer stalls when adding gas or does not hold idle revs, the adjustment screw settings are most likely to have gone wrong. On the body of the carburetor are usually three screws: L (Low) regulates the supply of fuel at low speeds, H (High) on high, and T or LA (Idle) is in charge of idling.
For cold start, it is important that the screw L It was set up correctly, providing a rich mix at the start. If the mixture is too poor, the engine will not catch. If you do, it will pour a candle. Factory settings are often confused by vibration or interference from inexperienced users. The standard procedure involves twisting the screws to the point (without fanaticism), and then twisting the screw. L 1-1.5 revolution for the initial start.
☑️ Diagnosis of the carburetor
Clogging of the chicklers and canals of the carburetor is another trouble, especially if the trimmer has stood with fuel inside for a long time. Gasoline resins clog the thinnest holes, and the fuel stops flowing into the cylinder. In such cases, a complete dismantling, ultrasonic cleaning or replacement of the remplekt is required. Particular attention should be paid to the condition of the membranes, which eventually tan and cease to perform their pumping function.
⚠️ Attention: When cleaning the carburetor, do not use metal wire or needles to clean the jelly. You can change the diameter of the hole, which will lead to impaired mixture formation and the inability to restore normal operation of the engine.
Air filter and air supply
The engine needs not only gasoline, but also clean air. If air-filter clogged with dust, grass or soaked in oil, air access is limited. This leads to the re-enrichment of the mixture: gasoline is supplied a lot, and air is not enough. As a result, the candle “throws”, and the trimmer stops starting or works with severe interruptions, releasing black smoke.
Regular filter cleaning is a mandatory procedure for each tank of fuels produced or after each work in dusty conditions. Filters are made of foam, felt or a special mesh. The foam can be washed gently in soapy water, thoroughly dried and slightly oiled (if this is provided by the instructions). Feather filters are more difficult to clean, it is better to gently shake or blow them out, but not wet.
If the filter is torn or has lost its shape, it must be replaced. The entry of abrasive dust (sand, earth) into the cylinder through a damaged filter will lead to rapid wear of the piston group and loss of compression. In this case, the trimmer will start worse and worse until major repairs are needed.
Can I get a trimmer without an air filter?
Short-term start without a filter is possible for diagnosis, but long-term work is strictly prohibited. Dust trapped in the cylinder acts as an abrasive, scratching the walls of the cylinder and piston, which irreversibly reduces compression and engine life.
Compression and condition of the piston group
Low compression is a "death diagnosis" for a two-stroke engine, although not always definitive. Compression is the pressure created in the cylinder when the fuel-air mixture is compressed. If it is insufficient, the mixture does not ignite, and the trimmer does not start. You can check the compression with a compressometer (the norm for trimmers is 8-12 atmospheres) or manually by plugging the candle hole with a finger or cork and yanking the starter.
The reasons for the compression fall lie in the wear of piston rings, cylinder jacking or failure of the crankshaft coils. If the wear of the rings is small, sometimes using a more viscous oil or adding a small amount of oil to the gasoline (temporarily) helps. However, if there are deep bullies on the cylinder, you will need to seed or replace the cylinder with a piston.
It is also worth checking the tightness of the crankcase. Suction of air through the crankshaft or gaskets leads to the fact that the engine sucks in excess air, impoverishing the mixture. This is especially noticeable on a cold engine when the gaps are still large. To check the tightness, a special device (a pressing device) is used, which creates pressure in the crankcase and observes its fall.
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| Candle dry and white | Poor mix, air suction. | Adjustment of the carburetor, check of the ossuaries |
| The candle is black and wet. | Rich mix, clogged filter | Cleaning the filter, adjusting the screw L |
| Candle in oil | Wearing rings, lots of oil in the mix | Replacement of piston, correction of the proportion of oil |
| No spark. | Coil or candle malfunction | Candle replacement, coil check |
A dry candle when trying to start indicates that the fuel does not enter the cylinder (carburetor problem) or excess air enters the cylinder (suction).
The algorithm for starting a cold trimmer
The correct sequence of actions when starting a cold engine is often ignored by users, which leads to difficulties. Many immediately pull the starter, forgetting to close the air valve. For a cold start, it is necessary to create an enriched mixture, blocking the air supply.
First, you need to pump fuel into the carburetor if your model has a primer (soft silicone pear). Press it 3-5 times until the air bubbles disappear inside. Then transfer the engine control lever to the "Stop" position (so that a spark appears), close the air valve (the lever to the "Closed" position) and smoothly but sharply pull the starter until the first "snatching" (characteristic sneezing). Then open the valve and start the engine.
If the engine stalled after the first start, repeat the procedure, but without swapping the primer. The heating of the engine takes 1-2 minutes of work at idle speeds. Do not immediately give a full load, let the oil evenly distributed through the nodes.
What if the trimmer has stalled and does not start after warming up?
If the hot engine stalls and does not start, there may have been an “overheating” or “boiling” of fuel in the carburetor (steam plug). Allow the instrument to cool completely in the shade for 15-20 minutes. Check the oil level in the gearbox and the condition of the air filter. If the problem is repeated, it may be necessary to adjust the idling screw in the direction of increasing revs.
Can you use pure gasoline without oil?
Absolutely not. Two-stroke trimmer engines do not have an oil lubrication system. Lubrication is due to the oil added to gasoline. Starting on pure gasoline will lead to instant overheating, piston bullying and engine jamming in minutes.
Why does the trimmer start only when the valve is open?
This is a sure sign that the carburetor is preparing too rich mixture, or the air filter is clogged. The engine is “choked” by excess fuel. It is necessary to clean the filter and possibly twist the mixture quality screw (L) or the idle screw a little.
How to store a trimmer in winter so that it starts easily in the spring?
Before long storage, be sure to develop the entire fuel residue in the tank. Let the engine shut down on its own. This will prevent the membranes of the carburetor from drying out and the formation of resinous plaque. Store the tool in a dry room, removing the candle and dripping into the cylinder 5-10 ml of oil for preservation, and then several times turn the crankshaft.
Does the octane number of gasoline affect the start-up?
Yes, it does. Using gasoline with an octane number below the recommended (usually an AI-92) can cause detonation and make it difficult to start. The use of AI-95 is permissible, but only if it does not contain alcohol additives (ethanol), which aggressively affect the rubber seals of the carburetor.