For the small, compact Stihl 250 chainsaw mechanism, proper carburetor tuning is key. All coordinated work, all load conditions and its trouble-free operation directly depend on the adjustment of the fuel supply systems, the quality and quantity of the fuel-air mixture. This article describes how to adjust the carburetor for the Stihl 250 and configure all of its dosing systems.
When to adjust your Stihl 180 carburetor
To begin with, it’s worth deciding why, in general, you may need to adjust and repair the stihl ms 180 carburetor. So, you need to do this in the following cases:
- if the chainsaw does not keep idle;
- repairs may be required if the saw does not start;
- there is a loss of power;
- excessive fuel consumption;
- chainsaw does not develop the largest momentum.
- stalls at speed.
This list can be continued for a long time, but we have identified the main premises. Before proceeding with the adjustment, it is necessary to know what are the main parts of the carburetor on the Stihl 180 chainsaw, and who produces it.
Features of the Stihl MS230 chainsaw 14
Thanks to the generated power of almost 3 hp this unit is a semi-professional line of Stihl chainsaws. The large internal volume of the cylinder (40.2 cm3), the capacious gas tank and the level of balancing brought to perfection create all the conditions for many hours of continuous operation. Suitable not only for professional saw cutters who specialize in felling trees, but will also become an indispensable thing for everyday life.
In fig. 1 shows a modern carburetor for a German chainsaw manufactured by Stihl 250. It is a knot the size of half a human fist. The manufacturer of the movement is Walbro, Taiwan. Case material. stainless steel alloy. At the bottom of the device, a shutter is fixed, providing a uniform supply of the fuel-air mixture to the engine combustion chamber.
Fig. 1. Carburetor for the Stihl chainsaw.
Here, holes are made for attaching the assembly to the power unit housing. Between the flanges of the mixture supply and the combustion chamber of the engine, a gasket is installed. An accelerator pump is located under the throttle rod. It is a small piston with a rubber ring.
On the front of the case is a series of easy-to-use spring-loaded adjusting screws:
- idle move;
- maximum speed;
- amount of mixture;
- mixture quality.
The carburetor of the Stihl chainsaw is adjusted with these screws.
The main innovative feature of the carburetor for the Stihl 250 chainsaw is the heating device. In order to avoid freezing of the mechanism during operation during the winter period, it is equipped with a special system that preheats the steel case during operation. For this, the unit is switched to winter operation.
The body is blown with heated air drawn in from the engine. This mode of operation of the mechanism prevents icing, freezing of the nozzles, provides a normal flow of the fuel-air mixture. When switching to summer operation, the hot air damper closes. Summer mode is characterized by natural cooling of the unit.
Features of the Stihl 250 chainsaw
Features of the Stihl MC 230 chainsaw
230 Stihl, like many other company saws, are manufactured with the latest technology. Let’s see the main technologies used in the production of this chainsaw:
- Carburetor preheating. when working in the winter season, the chainsaw is switched to summer mode, the carburetor is blown with heated intake air, thus preventing icing.
- The innovative gas tank cap does not require a special key to open. Technology developed and patented by Stihl. The process of opening, closing takes place without difficulty, and the tightness, in turn, remains at its best.
- Anti-vibration system. Stihl, like Husqvarna, uses a special system to reduce the vibrations transmitted from the instrument to humans during operation. Without such a system, with prolonged work, the human body experiences heavy loads, which over time can lead to impaired blood circulation in the hands.
- Quickstop instantaneous chain stop. The well-known hand brake lever actuates the QuickStop mechanism, which allows you to instantly stop the work of the Stihl MC 230 chainsaw.
- Ematic chain effective lubrication system. The system includes an oil pump with variable oil flow, an Oilmatic chain and an Ematic guide rail. The peculiarity of the system is that the supplied oil reaches only those places where it is required, which allowed to reduce the oil consumption by half.
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Throughout the operation process, the need periodically arises for additional adjustment and ensuring the correct supply of the fuel-air mixture. How to determine exactly when and what kind of adjustment is necessary for the normal functioning of the equipment? There are characteristic signs when the mechanism, by the behavior of individual parts, itself suggests when adjustment is necessary.
First of all, each time before the next engine start, it is necessary to check the color of the spark plug electrodes.
By changing it, you can decide on the need for adjustment, adjustment of work processes, improving the quality of the combustible mixture:
- Black electrodes coated with soot or soot indicate a re-enriched air-fuel mixture entering the engine.
- Brick-gray electrodes indicate that the mixture is perfect in composition and no additional adjustments are required.
- White plaque on the candle electrodes indicates that the mixture is lean.
The signs described in paragraphs 1 and 3 indicate that carburetor adjustment is essential for the Stihl 250 chainsaw.
NOTE! Do-it-yourself adjustment of the Stihl 250 carburetor may be necessary for the owner if it has changed: fuel quality, altitude, or if air pressure has occurred at the place of operation of the chainsaw. Perhaps, humidity, temperature, atmospheric pressure has changed.
Exact settings will allow you to achieve maximum unit performance while reducing the external necessary conditions for its operation. Successful debugging of operating conditions prevents oil starvation and engine failure due to insufficient lubrication. After all, the lubricant enters the saw cylinder along with a lean air-fuel mixture.
A fuel pump is installed directly in the carburetor body, which operates under the influence of an air pulse from the crankcase of the chainsaw, transmitted through special channels. A diaphragm is installed in the pump; it is directly responsible for pumping fuel under the influence of an impulse. A gasket is installed between the diaphragm and the housing, which is responsible for the density of the fuel pump.
Preparing for carb adjustment
Of paramount importance when setting all the fuel metering characteristics of the Stihl 250 is the top-most adjusting screw located near the muffler. The factory setting, the parameters of which are shown on the upper plastic cover, provides that it must be twisted one revolution from a full twist.
Do-it-yourself Stihl 250 chainsaw carburetor adjustment is carried out throughout the operation process. Unscrewing the screw enriches the working mixture, since the air-fuel mixture receives a larger volume of gasoline, and twisting the screw depletes the working mixture, since the air-fuel mixture receives less gasoline.
Adjustment of the carburetor will not give positive results if air intake from the engine side takes place through:
- carburetor gasket;
- accelerator pump rubber ring;
- crankshaft oil seals.
Setting up the Stihl 250 carburetor is carried out only after a careful inspection, identifying the existing air leaks. The next stage of preparatory commissioning is the full maintenance of all components and mechanisms.
- cleaning from deposits, slags, resins;
- engine wash using solvent, acetone;
- spark plug replacement;
- cleaning, washing the air filter;
- checking the tension of the cutting chain;
- idle setting;
- engine warming up to operating temperature.
Then you can proceed to complex manipulation settings.
The dense placement of internal equipment and fuel and oil tanks made it possible to reduce the dimensions of the hull to a compact level, which does not exclude convenient access to the filler necks and tuning units of the fuel system.
- With its own weight of 4.6 kg, the tool does not create problems when performing complex sawing operations in hard-to-reach places.
- The Stihl 230 saw is powered by a two-stroke carburetor ICE operating on a dosed mixture of high-octane gasoline with special engine oil, which enters the fuel system from an internal tank with a volume of 470 ml.
- Power unit with a cylinder displacement of 45.4 cm3 and a power of 2.7 hp It is equipped with an easy-start system, an economical carburetor, and an air intake filter convenient for routine maintenance.
The advantages of the engine include a significant reserve of torque, economical consumption of the fuel mixture, increased engine life of the crank assembly, piston group with a wear-resistant coating, stable traction characteristics in all operating modes.