Starting a chainsaw Stihl after a long period of inactivity or cooling of the engine, it often becomes a test for the owner, especially if the exact sequence of actions is not followed. A cold carburetor requires the fuel mixture to be enriched for the first ignition, and it is errors in the control of the air damper that most often lead to “overflow” or the inability to start. Understanding the physics of how a two-stroke engine works helps to avoid typical mistakes when an inexperienced user simply pulls the starter to no avail.
Unlike a heated tool, a cold saw Calm needs to create conditions for fuel condensation in the cylinder. If you simply turn on the ignition and pull the cord, the spark will jump, but there will not be enough combustible mixture in the combustion chamber to cause a flash. That is why manufacturers have developed a special algorithm, ignoring which can lead to a flooded spark plug and complex repairs.
In this article we will analyze not only the standard procedure, but also the nuances that are often missed in official instructions. You'll learn how to position the tool correctly, why thumb position is important, and what to do if the engine sneezes but doesn't start. The right start is the key to the longevity of the piston group of your tool.
Preparing the tool for launch: security and checks
Before moving on to manipulating the levers, you need to make sure that the equipment is fully ready for work. Security When starting a chainsaw, it comes first, since the inertial mechanism may work unexpectedly. Make sure the chain is properly tensioned and the bar is not touching the ground, stumps or other objects that could spin.
Check the fuel mixture and oil levels in the chain lubrication reservoir. For two-stroke engines Stihl It is critical to use high-quality fuel with an octane rating of at least 95 and special air-cooling oil. Using old gasoline that has been sitting for more than a month can lead to the formation of gums that will clog the carburetor jets and make starting impossible.
⚠️ Attention: Never start a chainsaw while holding it suspended or with one hand. This could result in loss of control of the tool and serious injury.
A visual inspection of the air filter is also required. If the filter is clogged with sawdust, the engine will choke and the rich mixture at startup will not be able to ignite due to lack of oxygen. A dirty filter is one of the most common reasons why a saw stalls immediately after starting.
Algorithm for starting a cold engine: step-by-step instructions
The main secret to a successful launch lies in the correct operation of the combined control lever. On most models Stihl, such as MS 180 or MS 250, this lever has several positions and for a cold start it must be moved to the uppermost position, corresponding to the closed choke.
Place the saw on a flat, hard surface. Step firmly on the rear handle with your right foot to secure the tool. With your left hand, grasp the front handle with your thumb under handle, rather than grasping it from above - this is a safety rule that prevents the tool from being thrown out when jerking.
☑️ Check before start
Pull the starter rope smoothly but firmly until you feel resistance (compression), and then give a sharp, powerful pull. There is no need to pull the cord out to its full length or jerk it with small amplitude jerks. The engine should make a characteristic “grabbing” sound (first flash).
As soon as you hear this sound, immediately move the combination lever to the middle position (half-open). Now one confident jerk is enough for the engine to start and go to idle. If you keep the throttle closed after the first flash, the engine will stall due to the mixture being over-rich.
Carburetor adjustment and idle speed adjustment
If the chainsaw Calm starts, but stalls immediately or is unstable at idle; carburetor adjustment may be required. There are three screws on the body: L (Low) for low revs, H (High) for tall and LA (or T) for idle speed. For cold starts, it is the idle screw that is most often important.
Screw rotation LA clockwise increases engine speed, causing the chain to rotate. If the chain spins at idle, the screw must be unscrewed counterclockwise until it stops and the engine starts to run stably. Excessive enrichment of the mixture with screw L may make cold starting difficult.
| Parameter | Symptom of misconfiguration | Action |
|---|---|---|
| Idle speed | Engine stalls when releasing gas | Tighten the screw LA (increase speed) |
| Mixture enrichment (L) | Black smoke, carbon deposits on the spark plug, difficult start | Unscrew the screw L (lean mixture) |
| Lean mixture (L) | Saw squeals, overheating, risk of scuffing | Tighten the screw L (enrich the mixture) |
| Maximum speed (H) | The saw does not develop power during operation | Tachometer fine tuning |
Interfere with screw settings L and H Without a tachometer and experience, it is not recommended, as this can lead to overheating of the piston group.
When adjusting the carburetor, always warm up the engine to operating temperature. Tuning a cold engine will cause errors when running under load.
Common startup mistakes and how to avoid them
One of the most common mistakes is ignoring the position of the left thumb. Many users grip the handle from above, which, if the starter jerks strongly, can cause the hand to slip and hit the body or chain. The correct grip is when the thumb is under handle, providing reliable support.
Another mistake is too sluggish starter jerks. The decompressor mechanism (if there is one) or simply the inertia of the flywheel requires a sharp, energetic movement. Pulling the cable slowly will not create the required crankshaft speed for sparking and fuel delivery.
⚠️ Attention: If after several attempts the saw does not start, do not continue to pull the starter endlessly. This may cause the spark plug to become flooded with fuel.
Users often forget to turn on the ignition by moving the lever to the STOP or 0. In this position, no spark is generated, and no matter how much you pull the cable, the engine will not start. Always check the position of the toggle switch before starting work.
What to do if the chainsaw is “flooded” with fuel
If you tried to start the saw with the throttle closed, but the engine still did not start, most likely the spark plug was flooded. Excess fuel in the cylinder prevents the spark from breaking through the gap, and starting becomes impossible. In this case, it is necessary to carry out a drying procedure for the cylinder.
Unscrew the spark plug using the special wrench. If the electrodes are wet and smell of gasoline, wipe them with a clean rag or heat them over a fire (being careful). While the spark plug is drying, make 10-15 jerks with the starter with the spark plug unscrewed and the air damper open - this will purge the cylinder of excess fuel.
How to check the spark correctly?
Place the spark plug skirt on the metal part of the cylinder (ground) and pull the starter. The spark should be bright blue. An orange or weak spark indicates problems with the coil or spark plug.
After drying, screw the spark plug back in, but do not close the air damper yet. Try starting the engine in normal mode, as for a hot saw (lever in the middle position). If the engine seizes and stalls, try again.
Seasonal features and instrument storage
In the cold season, starting a chainsaw Stihl may be complicated by freezing of condensate in the carburetor or thickening of the lubricant. If you are storing the tool in an unheated area, allow it to warm up at room temperature for 15-20 minutes before use.
For winter operation, it is recommended to use winter oil for two-stroke engines, which retains its properties at low temperatures. Summer oil may become too thick, making it difficult to lubricate the bearings and piston group in the first seconds of operation.
During long-term storage (more than a month), be sure to drain the fuel mixture from the tank. Gasoline loses its properties, and the light fractions evaporate, leaving a tarry residue that clogs the carburetor. Start the saw and allow it to burn out any remaining fuel from the carburetor before storing it.
Draining the fuel before storage is a mandatory procedure that prevents 90% of carburetor problems the next time you start it.
Frequently asked questions (FAQ)
Why does the Stihl chainsaw start and immediately stall?
Most often this occurs due to incorrect adjustment of the idle screw (LA) or clogged fuel filter. The cause may also be air leaks through the seals or carburetor gasket. Check for leaks and clean the filters.
What is the best gasoline to use for Stihl?
It is recommended to use unleaded gasoline with an octane rating of at least 95 (AI-95). The fuel must be fresh, the shelf life of the mixture with oil should not exceed 1-2 weeks, depending on the quality of the oil.
Do I need to open the shutter after the first flash?
Yes, definitely. After the engine “caught” (made a sound), you need to move the lever to the middle position (half-open damper). If you leave the throttle closed, the engine will stall due to the mixture being too rich.
How often should you change your air filter?
The filter must be cleaned after every working day or when it is visibly dirty. Replacement is carried out as wear occurs, usually once a season or if the mesh is damaged. A dirty filter is the main cause of loss of power and difficult starting.