Launch gasoline engine chain saw may seem like a trivial task, but the model Stihl MS180 has its own technical nuances, ignoring which leads to difficulties when starting. Owners often face a situation where, after winter downtime or a long pause, the tool refuses to start, which causes panic and unnecessary calls to service.
Understanding the working principle two-stroke engine and correct execution of the sequence of actions allow you to avoid most problems. In this article, we will analyze in detail the algorithm for starting a cold and hot saw, and will also pay attention to the preparation of the fuel mixture, since it is the quality of gasoline and oil that most often causes equipment failure.
Don't underestimate the importance of regular maintenance. Even the most reliable German tool requires careful attention to the ignition and air supply systems. We'll look at common beginner mistakes and professional tricks that will get your business up and running in no time. Stihl in any conditions.
Preparing the fuel mixture and checking systems
The foundation for stable operation of any two-stroke engine is correct fuel mixture. For model MS180 the manufacturer recommends using high-octane gasoline (AI-92 or AI-95) and special synthetic oil for two-stroke engines. The mixing ratio is usually 1:50, that is, 20 ml of oil per 1 liter of gasoline, unless otherwise specified in the instructions for a specific oil.
Try not to store the finished mixture for longer than 30 days, as gasoline loses its properties and oil precipitates. Usage old fuel - one of the main reasons why the saw does not start or is unstable. Before each start, be sure to shake the canister so that the components of the mixture are evenly distributed.
In addition to fuel, condition is critical air filter. If it is clogged with sawdust or dust, the engine will not receive enough oxygen and the mixture will become too rich. This will cause the spark plug to flood and make it impossible to start. Regularly cleaning or replacing the filter is a simple procedure that will save you from many problems.
Visual inspection spark plugs also required. Unscrew it and inspect the electrode: dry carbon deposits indicate a lean mixture, black oily deposits indicate over-enrichment or excess oil. The normal electrode color is brick brown. If the spark plug is wet from gasoline, it must be dried and cleaned before installation.
⚠️ Attention: Never use pure oil or used oil to prepare the mixture. This will lead to the formation of carbon deposits on the piston group and engine failure.
Use only fresh fuel mixture, prepared no more than a month ago. Old gasoline loses octane and evaporates, leaving a tarry residue in the carburetor.
Cold engine starting algorithm
Launch cold engine is a process that requires precise adherence to the sequence of actions. Unlike a warm engine, a cold cylinder requires a rich mixture for first ignition. First, make sure that the chain brake is engaged: move the brake lever forward until you hear a characteristic click. This will protect you from accidentally turning the chain.
Next you need to activate decompression valve (if your modification has it) or simply press the fuel pump (primer) 3-5 times until air bubbles appear in the tube. This action supplies gasoline to the carburetor, making the first start easier. Then move the throttle control lever to the Closed or Start.
Place the saw on a flat surface and firmly press the toe of the rear handle with your foot. With a sharp and strong jerk of the starter cable, pull it out until the engine grabs for the first time. As soon as the engine “sneezes” or tries to start, move the choke lever to the position Open (or half open) and repeat the jerk. The engine should start.
Let the engine warm up at idle speed for 30-60 seconds. Don't start sawing right away, let piston group reach operating temperature. Release the throttle trigger to return the saw to idle speed and check to see if the chain is spinning at idle. If the chain rotates, the idle screw needs to be adjusted.
☑️ Check before cold start
Starting a warm chainsaw
Launch situation hot engine radically different. If you have just been working and the engine stops (for example, you run out of wood or need to change position), the procedure is simplified. In this case, there is no need to enrich the mixture, since there is already enough fuel vapor in the cylinder.
Make sure the throttle lever is in the Open (normal operation). Engage the chain brake for safety. There is no need to use a fuel primer if the saw has been running recently - this may lead to overfilling.
Make one confident jerk with the starter. Warm up Stihl MS180 should start almost instantly. If the engine does not start the first time, it may have cooled down, and then it is worth repeating the procedure for a cold start, but without fanaticism with pumping fuel.
If you take a break from work for more than 15 minutes, it is better to turn off the engine completely to avoid coking of the rings and spark plugs.
Why is it difficult to start a hot saw?
If a hot engine does not start, most often the reason is “too much” fuel. The spark plug is filled with gasoline, and the spark cannot penetrate the wet gap. In this case, you need to unscrew the spark plug, blow out the cylinder with the starter (with the ignition off), wipe the spark plug and put everything back together.
Carburetor settings for stable operation
If the saw starts but stalls when gas is added or is unstable, you may need to carburetor adjustment. On the model MS180 There are usually one or two adjustment screws (depending on the carburetor version). The main screw regulates the quality of the mixture at idle speed.
Rotating the screw clockwise usually makes the mixture leaner (less fuel), while counterclockwise tends to make it richer. Correct tuning ensures smooth engine idling without stalling and a confident increase in speed when you pull the trigger. Do not turn the screws randomly, make a quarter turn at a time and listen to the changes in the sound of the engine.
For precise adjustment, it is recommended to use a tachometer so as not to exceed the maximum speed and damage the engine. However, experienced users can tune the saw by ear for maximum traction and stability. If the screw is turned too far, the mixture will become too rich and the engine will begin to choke.
| Symptom | Possible reason | Action |
|---|---|---|
| Engine stalls at idle | Mixture too lean | Loosen quality screw (L) 1/4 turn |
| Black smoke from muffler | Excess oil in mixture | Drain fuel, prepare new mixture 1:50 |
| The saw does not gain speed | Air filter clogged | Wash or replace the filter |
| Strong vibration | Uneven chain wear | Sharpen or replace the saw set |
Remember that the factory carburetor setting is optimal for most conditions. You should only interfere with the settings if there are clear signs of malfunction or after repairing the fuel system.
The factory setting of the Stihl MS180 carburetor is the most balanced. Adjustment is only required when changing altitude or after replacing fuel system components.
Typical faults and methods for their elimination
Even if all the rules are followed, situations may arise when chainsaw refuses to work. One common problem is lack of spark. Check the spark plug tip: it should fit tightly on the electrode. If there is no spark, replace the spark plug with a new one, first checking the gap.
Another common cause is clogging fuel filter in the tank or fuel channels. Over time, a resinous coating forms in the tank, which clogs the mesh. Cleaning the tank and replacing the filter is a mandatory procedure if the saw has been idle for a long time.
Air leaks through the crankshaft seals or gaskets can also prevent starting. The engine does not create enough vacuum to supply fuel. This can be diagnosed by spraying water on the joints of the crankcase while the engine is running: if the speed changes, it means there is suction.
- 🔧 Check the status fuel hose: It should not have cracks or creases.
- 🔧 Inspect the muffler for carbon deposits: if necessary, remove and clean it of combustion products.
- 🔧 Make sure it's working properly starter mechanism: the cable should not be shaggy, and the ratchet should be clearly fixed.
⚠️ Warning: If you smell gasoline but the saw does not start after several attempts, do not continue to pull the starter. You have “flooded” the candle. Let the saw sit for 10-15 minutes or remove the spark plug to dry.
Seasonal storage and preservation of instruments
Correct conservation chainsaws before long-term storage (for example, for the winter) is a guarantee that in the spring it will start the first time. The main mistake is to leave gasoline in the tank and carburetor. The gasoline evaporates, leaving a sticky resin that tightly clogs the jets.
To preserve Stihl MS180, exhaust the remaining fuel in the tank until the engine stops completely. After this, unscrew the spark plug, pour 5-10 ml of engine oil into the cylinder and slowly turn the crankshaft with the starter several times. This will create a protective film on the cylinder walls and piston.
Wipe the saw body from dirt and grease, lubricate the bar guide and chain. Store the tool in a dry place, preferably in a case, to prevent dust from getting into the air filter. Following these simple rules will extend the life of your instrument by years.
Do not forget that rubber elements (seals, gaskets, fuel hoses) age not only from work, but also from time. If the saw is more than 5-7 years old, it is recommended to replace the fuel hoses and seals before the active season, even if they look intact.
Is it possible to store the saw with a full tank?
You can only store the saw with a full tank for 2-3 weeks. For long-term storage (a month or more), the tank must be completely empty and the carburetor must be dry of any remaining fuel.
Safety precautions during startup and operation
Starting a chainsaw is a potentially dangerous procedure. Always start the engine while holding the saw firmly with both hands and make sure that chain does not touch the ground, branches or other objects. A rotating chain may throw foreign objects or injure the operator.
Use personal protective equipment: glasses, gloves, thick clothing and shoes. When starting indoors (which is highly undesirable), make sure there is good ventilation, as exhaust gases contain carbon monoxide, which is odorless but deadly.
Never run the saw if the chain guard is removed or damaged. The chain brake mechanism must be in good working order and respond instantly to an inertial impact. Your safety depends not only on your skills, but also on the serviceability of the tool’s protective systems.
- 🛡️ Always keep your left thumb under the handleso that the saw does not break out of your hands during the scan.
- 🛡️ Do not run the saw near flammable liquids or gases.
- 🛡️ Watch the chain tension: a loose chain can jump off the tire and cause injury.
What to do if the saw does not start after winter?
Most likely, the fuel in the carburetor has dried out. Try removing the carburetor cover, wiping the insides with a clean rag, and blowing out the fuel passages. If this does not help, you will need to completely disassemble and ultrasonic clean the carburetor.
What oil is best for Stihl MS180?
Use only oils labeled Stihl HP Ultra or similar synthetic oils for high-end two-stroke engines (JASO FB, FC, FD). Mineral oils produce more carbon deposits and require more frequent cleaning.
Why does the saw only start when the damper is open?
This is a sign that there is too much fuel in the cylinder (rich mixture). The spark plug is flooded and requires additional air to start. You need to dry the spark plug, check the air filter and, perhaps, lean the mixture a little with the adjusting screw.