You can't live without a chainsaw in your household. Therefore, you need to know the rules of use and maintenance. First of all, this concerns the performance of the carburetor. The efficiency of the chainsaw depends on this part. Therefore, the carburetor of the Stihl chainsaw must be adjusted in a timely manner in compliance with the technology. If you have knowledge and a little experience, you can do this yourself.
What carburetor is used?
The Stihl MS 250 chainsaw uses a carburetor from the Japanese company Zama, model C1Q-S85. It is reliable, practical and easy to adjust.
Among the disadvantages is the cost of both the carburetor itself and its components (including the repair kit).
If you wish, you can save money and buy a repair kit on AliExpress, so it will cost 3-4 times cheaper and will cost about 500 rubles.
The Zama C1Q-S85 carburetor is installed on almost all Stihl chainsaws, for example on the MS210, MS230 models.
Appearance of the Zama C1Q-S85 carburetor
When customization is required
Modern “three-screw” carburetors of Carver chainsaws are practically not designed for manual adjustment at home. The screws are provided for factory settings, are securely secured against rotation during vibration by tenacious springs and do not change their position arbitrarily.
But the screws on the carburetors of Carver chainsaws can be adjusted through special holes without removing the casing using a regular screwdriver. This suggests that such models structurally require carburetor adjustment from time to time.
The reason for this cannot be precisely stated from a technical point of view. Only versions are possible:
- The carburetor of the Carver chainsaw is located in an area of high vibration, which causes the screws to unwind spontaneously.
- A rough spring is installed, which cannot fix the screw as on other models.
- Periodic adjustment is required due to the technical features of the carburetor and the internal combustion engine of the Carver chainsaw as a whole.
Device and principle of operation
The carburetor of the Stihl MS 250 chainsaw is a membrane type and performs a standard function - mixing fuel with air in the required proportion to obtain an air-fuel mixture and further supplying this mixture to the combustion chamber of the engine.
Diagram of the carburetor of the Stihl 250 chainsaw, at position No. 9 there is a membrane.
The principle of operation of the Shtil 250 carburetor. Gasoline is shown in blue, air in beige. The arrows indicate the direction of the flows. Number 13 shows a membrane that controls the amount of mixture supplied.
Read more about the design and operating principle of a chainsaw diaphragm carburetor here.
Specifications
The Stihl MS-660 professional chainsaw is equipped with a fifty-one cm variable bar and a spare chain. Replacing parts is quick, which makes it possible to work with thick trunks and then cut out branches.
The Chinese chainsaw has the following characteristics:
- Power 7.1 hp (5.22 kW)
- Engine capacity 91.6 cm³;
- Chain saw pitch nine mm;
- Chain thickness 1.6 cm;
- Number of links in chains 72, 90, 162;
- Fuel consumption 0.4-0.8 l/h;
- Fuel tank capacity 0.83 l
- Oil tank capacity 0.36 l
- Tire length 40, 50, ninety cm;
- Weight fully charged 7.3 kg.
Specifications may vary slightly as manufacturers make changes and modifications to their products.
Adjustment
When purchasing a new chainsaw, the Stihl MS 250 carburetor does not require adjustment - everything is set up from the factory and ready to go! It is required only after a certain period of operation, as a result of which its parts have worn out or broken.
Another reason why you need to disassemble the carburetor is debris getting into the channels. In this case, it is enough to disassemble everything, wash it in gasoline, blow all channels with compressed air and put it back together.
When to adjust?
The first sign that the carburetor needs to be cleaned and adjusted is black (rich mixture) or very light (lean mixture) carbon deposits on the glow plug. With normal adjustments, an optimal ratio of gasoline to oil and a correctly adjusted fuel supply to the internal combustion chamber, the soot on the spark plug will be gray-brick.
Required Tools
To adjust, you will need a tool that everyone has: a set of screwdrivers, a set of open-end wrenches.
The materials you will need are rags and kerosene (gasoline) for washing parts.
Tachometer – for precise adjustment of carburetor speed. This is an important thing, but you can do without it.
Preparation
Before adjusting the carburetor, perform preventive maintenance of the unit:
- The air filter is cleaned;
- The entire carburetor is cleaned;
- The engine is cleaned and washed from dust and dirt;
- The circuit is being adjusted;
- The spark plug is cleaned or replaced.
Setup instructions
Step-by-step algorithm for adjusting the Zama C1Q-S85 carburetor on a Stihl MS 250 chainsaw:
- After stopping the engine, it is necessary to completely tighten the screws “H” and “L”, and then unscrew each one full turn.
- Next, you should start the engine - the chainsaw should idle for 5-10 minutes.
- By adjusting screw “H” you need to achieve maximum engine speed (14,000 rpm) with the throttle fully depressed. To accurately determine engine speed, use a chainsaw tachometer. If it is not there, the adjustment should be made by ear - you need to set the maximum speed and then reduce it by about 20-25%.
- Using the “LA” screw, you need to adjust the idle speed so that the chain on the bar rotates slightly, and then you need to unscrew the “LA” screw 1/4 turn.
- If the chainsaw stalls or the speed constantly changes, you need to unscrew the “L” screw, and the engine speed should increase.
- Next, use the “LA” screw to set the optimal engine idle speed, while the Stihl MS 250 should operate at 2600 rpm. This is idle speed.
If the carburetor or cylinder is sucking air, these procedures may not help. Air can enter the engine through a leaky carburetor gasket, crankshaft seals, or accelerator pump.
How to fix this problem, see the video below; the author also talks about adjusting the Zama C1Q-S85 carburetor. In the example, the chainsaw does not start well and stalls during operation.
Setup video
We also suggest you watch another interesting video, the author of which clearly shows how to adjust the carburetor on a Stihl MS 250 chainsaw.
Preparation for tuning, carburetor parts for its implementation and safety precautions
Before adjusting the UPT, you must make sure that both filters (air and fuel) are clean. In addition, there should be no air leakage into the engine from the side (through the seals, the gasket under the UPT or its accelerator pump, or anywhere else), otherwise it will not be possible to adjust the carburetor.
Preparing to adjust the carburetor
Almost any UPT is adjusted with 3 screws:
- The main jet bolt, designated "H" and used to set the maximum speed of the saw motor.
- The idle jet bolt, designated "L" and used to set low speed. That is, to regulate idle speed.
- The idle adjustment bolt, designated in various cases, “LA” (Stihl), “T” (Partner, Husqvarna).
There are also carburetors with fewer adjustment screws. In this way, manufacturers protect their products from unprofessional intervention and at the same time try to simplify their setup.
For safe regulation during its implementation, the following rules should be followed:
- The tool must be firmly installed on a flat surface of a rigidly fixed object (workbench, rack, table).
- The chain should be directed away from yourself and others present.
- There must be a safe distance between the chain and any surrounding objects to ensure that they cannot come into contact.
Malfunctions and repairs
During long-term use, the chainsaw breaks down, let's see what problems with the carburetor of the Stihl MS 250 saw are most common and how to fix them yourself.
Pulling out the studs
The carburetor for the Stihl MS 250 chainsaw is attached to the engine cylinder body on two studs with M6 threads. During long-term use, the carburetor is removed from time to time to clean and replace worn parts, so the threads on the studs may be damaged.
Replacing the studs with new ones takes very little time. Typically, such threaded hardware is not supplied in a repair kit, so you need to buy them at a hardware store. This is a 100-120 mm long pin with an M6 external thread . It is also better to replace nuts with a flange for studs with new ones. It is better to replace all these parts with parts made of high-quality steel.
Overflow
If the carburetor “overflows,” then this means only one thing: the membrane has dried out and hardened, so its pressure on the rocker arm has become excessive and uncontrollable. To replace the membrane, you need to remove the carburetor from the chainsaw body and disassemble it;
Wear of pipes
The rubber inlet pipe of the carburetor serves to connect it to the internal combustion chamber - this is the fuel pipeline. After prolonged exposure to oil and gasoline, rubber begins to crack and stretch, and the connection loses its tightness.
To replace the pipe, you can buy it separately or in a repair kit. The pipe comes with a seal, which can also be deformed and therefore must be replaced.
Features of the Shtil MS 230 chainsaw
230 Shtil, like many other saws of the company, are manufactured using the latest technology. Let's look at the main technologies used in the production of this chainsaw:
- Preheating the carburetor - when working in the winter season, the chainsaw is switched to summer mode, the carburetor is blown with heated intake air, thus preventing its icing.
- The innovative gas cap does not require a special key to open. The technology was developed and patented by Stihl. The process of opening and closing takes place without difficulty, and the tightness, in turn, remains at its best.
- Anti-vibration system - Stihl, like Husqvarna, use a special system to reduce vibrations transmitted from the tool to a person during operation. Without such a system, during prolonged work, the human body experiences heavy stress, which over time can lead to poor circulation in the hands.
- Instant chain stop with QuickStop brake. The well-known handbrake handle activates the QuickStop mechanism, which allows you to stop the Shtil MC 230 chainsaw at lightning speed.
- Ematic chain lubrication system. The system includes a variable oil pump, Oilmatic chain and Ematic guide bar. The peculiarity of the system is that the supplied oil reaches only those places where it is required, which has reduced oil consumption by half.
Repair kit
The repair kit for Zama C1Q-S consists of a fuel pump diaphragm, a fuel pump diaphragm, a gasket for the diaphragm, a gasket for the diaphragm, and a shut-off needle. For the MS 250 saw, the original repair kit costs from 2000 rubles and more. On AliExpress, a similar repair kit can be bought for only 500 rubles. Buy a repair kit.
The complete repair kit includes:
- membrane,
- gaskets,
- metal elements of the carburetor (jet jets, needles).
Conclusion
To summarize, it is worth noting that the semi-professional chainsaw, the Stihl MS 230, is in great demand due to its good performance indicators. True, you will have to pay for them, because... The cost of the saw is far from being in the budget segment. The main malfunctions that need to be eliminated are related to the carburetor; videos from experts (published in the article) or the services of specialized centers will help you in solving these problems. Serious malfunctions occur very rarely, but even here everything can be solved. All this speaks about the reliability of German Stihl saws. We recommend this chainsaw as a choice for those who need a reliable, more powerful tool for every day, to solve problems of medium complexity.
How to distinguish an original carburetor from a fake?
Remember these 4 simple rules, you will need them during your purchase:
- On Chinese unlicensed carburetors you can often see narrower cuffs than on the original product;
- The color of the carburetor body alloy on the counterfeit is brighter than it should be due to the increased proportions of aluminum;
- For the original product, instructions are included;
- And most importantly, the cost of a fake is always much lower than the price of the original.
A properly adjusted carburetor of the Stihl MS 250 chainsaw allows you to make maximum use of the power of the chainsaw, reduce fuel consumption and extend its life. It is very important to have experience setting up such a tool in order to correctly set the maximum speed. If you have no or insufficient experience, we recommend stocking up on an electronic tachometer before setting up.
Model specifications
The advantages of this household garden tool include good factory parameters, which allow the model to be used for work under increased loads.
The main characteristics of the chainsaw include:
- engine power – 2.7 liters. s./2 kW;
- cylinder volume – 40.2 cm3;
- idle/maximum speed – 2800/10000 rpm;
- permissible length of the installed tire is 30–35 cm;
- the recommended pitch of the chain used is 3/8 “;
- vibration right/left – 6.9/8.9 m/s2;
- noise level during operation – 113 dB.
The Stihl MS 230 C BE 16 chainsaw has a modest weight - with full tanks and an installed saw set, the model weighs 4.6 kg.
Operational Capabilities
The Shtil 250 saw is characterized by versatility of use, economical use, and stability of operating parameters throughout the overhaul and operational life.
- The tool produces transverse, longitudinal and diagonal sawing of any type of wood with equal success; the length of the bar allows you to work with material with a diameter of up to 35 cm.
- Modern materials and new processing technologies are used in the production of this model. The saw is assembled at a high technological level, reducing the likelihood of failure or malfunction to a minimum.
- Precise tuning of fuel equipment allows you to use the traction and economical resources of a standard engine with maximum efficiency.
- The operating instructions supplied with the tool include information on preparing the saw for use, maintenance features, and troubleshooting and troubleshooting.
- The repair range is represented by a fairly wide selection, allowing you to restore the functionality of a worn-out component or system with minimal time.
How to determine the advance angle of the built-in ignition?
The design features of the built-in ignition coil ensure a match between the optimal factory position of the moving piston and the discharge of the spark plug. During operation of 4-stroke power units, the spark must jump before the piston returns to its uppermost position. This is due to the fact that such engines take longer to burn fuel. In their factory design, the speed of operation of internal combustion engine parts is equal to the speed of planned ignition of the filled fuel. In this regard, the piston has time to travel a certain distance from the moment the created spark instantly jumps to the place where the spark plug is located, to the period during which the burning gases are guaranteed to create extremely high pressures.
Performance properties
In the development of this model, valuable experience in operating proprietary and similar designs of other brands was used.
The capabilities of the tool allow for partial or complete mechanization of work:
- to clear areas of small trees and tall bushes;
- wood fuel procurement;
- formation of crowns of trees growing on the site;
- construction of wooden buildings for residential and special purposes.
Lightweight, convenient and safe to use, the Shtil 170 saw has proven itself in all respects in a wide range of works of varying complexity to create exclusive elements of landscape and architectural design.
Structural components
All engines, be it a car or another instrument using an internal combustion engine, have similar operating principles.
No exception, there are such famous chainsaws that are used with pleasure by consumers such as Goodluck, Shtil or Husqvarna.
The drive in them is the familiar internal combustion engine, respectively the fuel tank, the engine and the working element that directly performs the work, as well as other attachments that help with control.
Sometimes during operation some problems may arise with this fairly reliable tool like a chainsaw.
Troubleshooting muffler problems
If the chainsaw engine operates normally at low speeds, but starts to stall and smoke at high speeds, the problem may be hidden in the muffler.
To check the quality of its work you should do the following:
- dismantling (with mandatory closing of the outlet);
- disassembly (if the muffler is dismountable);
- cleaning from carbon deposits using special detergents or the dry method;
- drying (using a hair dryer);
- reassembly and installation.
To prevent clogging of the muffler during operation of the chainsaw, you should carefully monitor the composition of the fuel mixture and the quality of its components.
