Chainsaw carburetor adjustment calm 660

What carburetor is installed on the Stihl MS 660 chainsaw

The carburetor of the Stihl MS 660 chainsaw is of a membrane type, which allows it to work even in an inverted position. The company has more than half a century of chainsaw production, so each unit is perfect enough.

Non-original products from other manufacturers most often have an identical design.

Chainsaw Stihl MS 660. one of the most powerful in the world (7.1 HP), professional grade.

Therefore, the carburetor on it is distinguished by increased throughput, sufficient for such an engine size, and reliability.

The device and principle of operation of the carburetor chainsaw Stihl MS 660

The carburetor of this model consists of almost 50 parts, including fasteners.

The main nodes of the carburetor of the Stihl MS 660 chainsaw:

• The body is made of light alloys of non-ferrous metals, with channels for supplying a fuel-air mixture, a storage chamber.
• Diffuser and chamber in housing for fuel atomization.
• Nozzles with calibrated holes for metering fuel supply.
• Air and throttle valves.
• Needle valve for opening and closing the gasoline supply channel from the tank.
• Elastic diaphragm for positioning the needle valve.
• Manual fuel priming pump for starting a cold engine (primer, or suction).

When you first start a cold chainsaw engine, gasoline is manually pumped up with a primer button. The first jerks of the starter are made with the air damper closed. After setting and during operation of the internal combustion engine, the air damper opens.

During the operation of the internal combustion engine, a vacuum is formed in the combustion chamber, and the mixture is sucked in automatically.

At idle, the flow of the mixture is limited by a closed throttle valve with an opening for a small amount of fuel.

The throttle position is adjusted when the chainsaw is running with the throttle handle. When the handle is pressed, it opens, the fuel supply to the internal combustion engine increases, and vice versa.

For normal operation of the internal combustion engine, the mixture must be optimal in terms of the proportions of fuel and air, which is achieved by adjusting the carburetor of the Stihl MS 660 chainsaw.

Current setting

Experienced operators in the process of work may notice that the internal combustion engine of the chainsaw has begun to work worse. Sometimes it is enough to turn the screws H and L alternately in one direction or another by a small step of 1/5. 1/6 of a turn and immediately check the result of adjusting the carburetor in real work. This is one of the easy ways to get a good setup.

The video material contains information on how to tune the carburetor of a chainsaw and check the tuning result.

Idle speed adjustment

Carried out with LA screw.

Adjustment is required if the engine stalls at idle. few revolutions, or the chain scrolls. many revolutions.

Reduce RPM by turning screw LA counterclockwise until the chain stops, then unscrew back 1 / 5-1 / 4 turn.

Adjustment by screw LA is almost always required after adjusting screw L, which also changes the parameters of the engine at idle.

Screws LA and L regulate idle speed in principle differently. L Changes the quality and quantity of fuel delivery through the calibrated holes. LA is called “booster” because it affects the position of the throttle at idle.

Features and differences of carburetor adjustment on a Chinese chainsaw

The carburetors on Chinese chainsaws are mostly copied from the original Stihl design. Therefore, the adjustment algorithm on the original and Chinese versions is almost identical.

Non-original products are worse in that they use low quality alloys, short-lived plastic parts (membrane and gaskets), the dimensions of the calibrated holes are not exactly maintained, etc.

For informational purposes, we recommend watching an interesting video about the Chinese chainsaw Calm MC 660. The chainsaw is fully disassembled, the condition of the components, including the carburetor, is assessed. Also, the author of the video disassembles the carburetor and shows by example how to clean it from dirt.

DIY Stihl MS 660 chainsaw carburetor adjustment

All carburetors on Stihl MS 660 chainsaws are factory set at equipped stands. This ensures the best operating parameters of the internal combustion engine in all modes. Settings get lost very rarely. Before adjusting, you need to make sure it is necessary. Deterioration of the internal combustion engine can be caused by other reasons:

• Clogged air filter.
• Spark extinguishing grille and muffler outlet pipes clogged with carbon.

If there are no problems with them, or they have been eliminated, and the internal combustion engine does not work normally, they begin to adjust.

The carburetor of the Stihl MS 660 chainsaw has three adjusting screws:

• LA for idle speed control.
• H for adjusting the fuel supply at high speeds (main screw).
• L to adjust the fuel and air proportions (mixture quality screw).

The L and H screws are located side by side, LA away from them. All of them are marked on the body.

Standard or basic adjustment

Screws H and L are tightened clockwise until the end, counting the number of revolutions made. Their number is recorded or remembered. If, as a result of unsuccessful carburetor adjustment, the engine cannot be started, this data will allow you to return to the original factory settings.

The chainsaw guy shop talk Stihl MS 660 carburetor testing, repair 11 27

• Screws H and L are unscrewed back counterclockwise, each one turn.
• The engine is started and checked by ear or by a tachometer.
• If the revolutions fail (suffocate) when the throttle is pressed, the screw H is unscrewed by another 1/4 turn.
• If, when the throttle handle is pressed, the engine operates as at idle, tighten the screw L by 1/4 turn.

Each Stihl MS 660 chainsaw that has worked for some time has its own characteristics, including the compression ratio in the cylinder. Therefore, the setting is individual. By turning 1/4. 1/3 of a turn of the screws H and L in one direction or the other, they achieve optimal operation of the chainsaw engine at medium and maximum revolutions.

Current setting

Experienced operators in the process of work may notice that the internal combustion engine of the chainsaw has begun to work worse. Sometimes it is enough to turn the screws H and L alternately in one direction or another by a small step of 1/5. 1/6 of a turn and immediately check the result of adjusting the carburetor in real work. This is one of the easy ways to get a good setup.

The video material contains information on how to tune the carburetor of a chainsaw and check the tuning result.

Idle speed adjustment

Carried out with LA screw.

Adjustment is required if the engine stalls at idle. few revolutions, or the chain scrolls. many revolutions.

Reduce RPM by turning screw LA counterclockwise until the chain stops, then unscrew back 1 / 5-1 / 4 turn.

Adjustment by screw LA is almost always required after adjusting screw L, which also changes the parameters of the engine at idle.

Screws LA and L regulate idle speed in principle differently. L Changes the quality and quantity of fuel delivery through the calibrated holes. LA is called “booster” because it affects the position of the throttle at idle.

Features and differences of carburetor adjustment on a Chinese chainsaw

The carburetors on Chinese chainsaws are mostly copied from the original Stihl design. Therefore, the adjustment algorithm on the original and Chinese versions is almost identical.

Non-original products are worse in that they use low quality alloys, short-lived plastic parts (membrane and gaskets), the dimensions of the calibrated holes are not exactly maintained, etc.

For informational purposes, we recommend watching an interesting video about the Chinese chainsaw Calm MC 660. The chainsaw is fully disassembled, the condition of the components, including the carburetor, is assessed. Also, the author of the video disassembles the carburetor and, by example, shows how to clean it from dirt.

What is needed to adjust

To access the adjustment, simply remove the top housing cover and the air filter. Therefore, only a screwdriver for the slots of the adjusting screws is required from the tool.

An electronic tachometer is required for professional carburetor adjustment. It accurately indicates idle and maximum rpm. Idle speed of the Stihl MS 660 chainsaw. 2,500 rpm, maximum. 13,000 rpm.

Without a tachometer, the quality of the carburetor adjustment is determined by ear and by the real operation of the internal combustion engine of the chainsaw.

Chainsaw Calm 660 Carburetor Adjustment

DIY chainsaw carburetor setting

For an independent carburetor option, you need to familiarize yourself with its device and understand the procedure for the work that is carried out to adjust the parts responsible for the correct functioning of the component parts of the device and parts close to it.

It is necessary to carefully handle the items for the system option, also to determine if the set characteristics correspond to very permissible values.

Stihl Ms 660 Carburetor Adjustment

Most chainsaw carburetors have three adjustment screws:

• L. jet screw for adjusting low speed
• H. jet screw for high speed adjustment
• Screw. T at Partner and Husqvarna (at Calm LA). adjustment idling chainsaw

The H and L screws adjust the ratio of the mixture of gasoline and air, which is determined by opening the throttle valve of the carburetor. When the screws are unscrewed, the mixture is enriched, and the revolutions increase accordingly, when the screws are tightened, the mixture becomes leaner. the revolutions fall.

The screw T (LA) is designed to adjust the idle speed. The basic “tuning” of the chainsaw is carried out at the factory during the final test. The carburetor is usually adjusted for a richer (than optimal) fuel mixture. The factory setting must be retained during the first hours of saw operation. Then (optional) a more precise carburetor adjustment is made.

We begin the adjustment by setting the idle speed, for this we rotate the screw T (LA) counterclockwise, achieving a complete stop of the chain at stable engine speeds.

How much is

The product of the Chinese assembly of the Stihl MS-660 chainsaw is highly popular for its reliability, safety and ease of use. Users note the low noise and vibration level during the operation of the unit, a long service life and the ability to operate in winter conditions. A significant disadvantage for many professional lumberjacks and land owners is the price of the tool and spare parts for it. Sometimes you have to wait a long time for the necessary parts, which negatively affects the logging process.

Chainsaw performance calm 180

Characteristics of chainsaws calm

Repair and adjustment of the carburetor of the chainsaw calm 180

The Stihl 180 is a German chainsaw designed for gardening, logging, site clearing and other woodworking. Many people love it for its compactness and ease of use. The tool combines seemingly opposite qualities. power and maneuverability. German designers have tried to create this sample, but the MS 180 Stihl also has drawbacks that users face in various operating modes. Like all mechanisms, it tends to fail. What to do in such cases and is it worth contacting the workshops?

Carburetor repair and cleaning without spare parts

There are situations in life in which it is simply vital to repair the saw, but the necessary components are not at hand. For such cases, there is the following method: take out the carburetor, remove the membranes, and then put the rest in acetone and let it soak. Acetone will remove debris that is blocking the passage of various fluids. This method will not hit your. but it is not reliable. Such repairs will not ensure the long operation of the chainsaw, since the outdated membranes have not been replaced.

Checking and subsequent replacement of defective membranes

Calm 180 chainsaw carburetor membrane repair kit

Frequent malfunctions of the Stihl 180 carburetor

Malfunctions that can be solved by repairing the carburetor: It is worth noting that diagnostics may not always correctly indicate the problem. There are times when, due to different reasons, the same “symptom” occurs. And sometimes diagnostics can give false information, as a result of which you will not be able to correctly eliminate the cause of the breakdown. Pay due attention to diagnostics, but do not overestimate its importance.

The tool does not hold idle revolutions, and sometimes the revolutions “walk”. Most likely the idle jet is clogged. It is urgent to clean it, otherwise the saw will not be able to perform its functions. Another possible cause is a malfunction of the fuel system.

Sometimes this problem is solved by unclogging the valve that restricts the fuel tank. This valve regulates the output of gasoline and the passage of air. Do not forget to adjust the carburetor by changing the amount of air that is supplied to it. details about this operation can be found in the instructions included with the brand new chainsaw.

The Stihl chainsaw carburetor, without disassembling, can only be adjusted by the number of revolutions produced at idle. It is impossible to increase or decrease the fuel supply in various modes. Manufacturers have limited access to this adjustment by removing special screws. If faults are found in this system, it is possible, with experience, to increase the gap between the needle valve and the wall.
The saw does not start. The solution is the same as in the previous paragraph.

The tool began to consume more fuel, while its power was significantly reduced. Gasoline consumption and power are subjective concepts. To accurately determine these indicators, one cannot do without visiting special firms specializing in this tool.

Well, if these two indicators are visible “on the face”, then follow these steps:

Check if the chain is dull. A dull chain has a lower efficiency, and therefore the saw consumes more fuel.

Examine the fuel tank. Perhaps it has formed small mechanical damage, through which gasoline leaves imperceptibly.

Inspect the muffler carefully.

Clean the cooling system and exhaust system.

Farmertec MS660 carburetor tune starting point

The unit stalls immediately after operation or warming up. Experts call it hot.

The most common reasons are:

• Lack of air entering the carburetor. Replace inlet and outlet valves.
• Breakdown of the cooling system (overheating). It is possible that foreign objects have entered the pipes with cold air, which will need to be removed.
• Chainsaw stalls when position is changed. This only applies to tilting to the side, in the vertical state the saw functions normally. This problem even applies to serviceable chainsaws, because during the development the designers made a small mistake. The Stihl 180 fuel system has a special design, in which the fuel cannot escape from the tank on its side. Sometimes the problem lies in the clogging of the fuel pump.

The procedure for parsing, as well as tuning the carburetor of the Stihl 180 chainsaw: In order to carry out a high-quality repair of the carburetor, you will need to remove it. This is not difficult to do, but you need to be extremely careful. To begin with, we will prepare the workplace: install the lighting, lay out all the necessary tools. Understand that the carburetor is the main saw unit where the fuel and gasoline flows intersect. For stable operation, they must be cleaned of foreign debris.

Therefore, before the main work, you need to do the following:

• Remove and clean the muffler.
• Make sure there are no problems with fuel supply and combustion.
• Check the serviceability of the air and cooling filters.

The main stages of work (removal of the carburetor)

The best option would be to watch a training video. Fortunately, there are dozens of them on the Internet. There they will tell you everything in detail and professionally. As the saying goes: “It is better to see once than hear a hundred times” (in our case, read it). Schematically, this process can be written as follows: remove the protective cover, remove the rods and, finally, unscrew the unit to work with it.

Chainsaw carburetor adjustment Calm 180