How to adjust the carburetor on a Stihl 180 chainsaw

How to remove and reinstall?

In cases where it is necessary to clean the STIHL 180 carburetor or disassemble it, first you need to remove the unit from the chainsaw. This must be done in compliance with a certain algorithm of actions:

  • Put the protective cover for the chainsaw on the tire.
  • Remove the top cover of the chainsaw.
  • Remove the two nuts securing the air filter and carburetor.
  • Remove the air filter housing.
  • Disconnect the wire from the engine control lever.
  • Carefully remove the lever from the seat in the housing, at the same time disconnecting the air damper rod from it.
  • Pull the carburetor towards you and disconnect the fuel supply as well as the throttle rod.

To facilitate dismantling, you can additionally untwist the rear handle and disconnect the throttle rod first from it, and then only from the carburetor. This may be required, since without some experience, disconnecting the rod from the carburetor is quite problematic and it is easier to disassemble the handle first.

To install the part in place, follow the reverse order of the algorithm.

When removing and installing the chainsaw engine control lever, you should be extremely careful, since the seat on the saw body is the weak link of the saw, and very often inexperienced users break it.

How to adjust with your own hands, the nuances of the setting

The carburetor of the STIHL 180 chainsaw, indiscriminately, can only be adjusted for the number of idle revolutions. It is impossible to increase or decrease the fuel supply in different modes using special screws. The manufacturer restricts access to adjustments and does not install these screws. How to adjust the carburetor to the correct idle speed is described in great detail in the manufacturer’s instructions.

In the event of certain malfunctions, and with experience, it is possible to increase or decrease the fuel supply by increasing the clearance when opening the needle valve.

To increase the flow, the rocker arm of the needle valve in the distribution chamber must be bent up, and to decrease, down. This regulates the stroke of the needle and, accordingly, the throughput of the valve.

You should not carry out the adjustment yourself, since this must be done very accurately and in case of an error it is almost impossible to return the initial position of the rocker arm.

Throttle flap

The throttle valve is installed in the carburetor body and is responsible for increasing the supply of the fuel mixture directly to the engine cylinder. At the moment of pressing the gas, the throttle valve opens slightly, thereby increasing the throughput of the channel and fuel from the carburetor cavity, rushes into the cylinder in a larger volume.

Combustion of a larger volume of fuel increases the amount of generated energy, which affects the power and speed of the processes. The damper is installed on the shaft passing through the entire carburetor body. At the exit of the shaft from the housing, a mount for the gas cable is installed, next to it is a cone-shaped adjusting screw responsible for adjusting the idle speed. By tightening the screw, you can slightly adjust the position of the shaft and the damper installed on it, thereby increasing or decreasing the idle speed, slightly opening or vice versa closing the damper.

Fuel pump

A fuel pump is installed directly in the carburetor body, which operates under the action of an air pulse from the crankcase of the chainsaw, which is transmitted through special channels. A diaphragm is installed in the pump, it is she who is responsible for pumping fuel under the action of an impulse. A gasket is installed between the diaphragm and the body, which is responsible for the tightness of the fuel pump.

Device and principle of operation

So, the carburetor is designed and manufactured by a STIHL subsidiary called Zama. Original carburetors, on their body have a company logo that guarantees product quality.

The appearance of the Zama carburetor

Nozzle

The fuel injector is mounted in the carburetor body in such a way that it is a connecting link between the distribution chamber and the cavity in which the throttle valve is installed. Simultaneously with the fuel, air is supplied to the nozzle and an air mixture is formed. The nozzle has a check valve that blocks the flow of air in the reverse sequence, that is, from the throttle chamber to the distribution chamber.

Distribution chamber

In the distribution chamber, as in the fuel pump, there is also a membrane that opens and regulates the fuel supply by pressing a special rocker, while raising its needle valve.

Бензопила Stihl 180 глохнет при нажатии на газ

The cover of the chamber is the compensator body, which is attached to the carburetor with four screws, a gasket is installed between the body and the cover, which increases the height of the chamber and is responsible for sealing.

Read more:  Do-it-yourself adjustment of the carburetor of the partner 351 chainsaw

Malfunctions and repairs

After we examined the carburetor device, it will not be difficult to determine the reason why fuel enters the combustion chamber in a larger volume. This is due to the wear of the gasket between the compensator cover and the carburetor body. You ask how this might affect?

The answer is simple, by shrinking, the gasket releases the diaphragm on top of it a fraction of a millimeter down. She, in turn, will press harder on the rocker arm of the needle valve, it will open more than it should be and the fuel will flow in excess (it will start to overflow).

Another reason is the stretching of the diaphragm itself, this occurs as a result of natural wear and tear. It is impossible to prevent this process, but you can solve the problem by periodically changing all the gaskets, carburetor diaphragms, and the fuel pump. There is a repair kit for this.

When cleaning the chainsaw with compressed air, never blow into the fuel pipe, as this can stretch the diaphragm.

The STIHL MS 180 chainsaw does not start well. carburetor repair. Repair and carb tuning

The STIHL 180 chainsaw is a versatile garden tool that is widely used in the garden. So, it is used for cutting firewood, pruning trees and other greenish plantings.

The STIHL 180 chainsaw is not the least popular both in construction and in farming. She is very comfortable and simple to use. It also has a low price, which makes it more affordable for the population.

Unfortunately, no matter how high-quality the tool is, it breaks at some point. The prerequisite for this is that you are more likely to like wear or destruction of parts at the end of frequent use.

There is an option to remove some malfunctions with your own hands. In order to repair the chainsaw on your own, you should know the structure of the tool, as well as more frequent breakdowns and methods for their elimination.

Often, the oil system of the STIHL 180 chainsaw is damaged. Find such a malfunction, of course, by the dryness of the working circuit or the presence of a leak.

The solution to this difficulty must be started with a painstaking examination of the hose that supplies the oil. The connection of the hose with the fittings is also amenable to inspection.

During the inspection and repair of the oil complex of accounting programs, it is also necessary to clean the filter. Often, its contamination leads to poor oil flow.

adjust, carburetor, stihl, chainsaw

If there is an oil leak, then this means that the tightness in the system is disturbed. First, this concerns the hose and oil passages. In most cases, such malfunctions appear in the course of mechanical damage to parts of the accounting software complex.

The process of removing and cleaning the air filter

STIHL ms 180 carburetor repair

If, during the pressure on the gas, the chainsaw begins to stall, then the problem lies in the carburetor. Also, a sign of a malfunction of the carburetor will be a protracted start of the chainsaw and the impossibility of speeding up.

In most cases, such a malfunction appears during the wear of the rubber cuff, which is located on the piston of the fuel booster. During this, air is sucked in when starting the tool. Mostly such a breakdown appears after years of operation of the chainsaw.

The elimination of this malfunction is carried out in the following order:

  • Remove the carburetor. Unscrew the screw that holds the cover with the diaphragm. Turn the carburetor so that the pin is visible. It is necessary to remove the retaining ring from it and disconnect the air damper spring. Then the throttle valve. For this purpose, you need to unscrew the screw that holds it. Next, you need to remove the damper axis.
  • Pull out the accelerator with the spring. It has a cuff. The wear of this particular element leads to air leakage and engine stoppage after a recent start. The piston with the cuff must be replaced.
  • Assemble the carburetor in reverse order and install it on the chainsaw.

Now it is clear how to remove a frequent malfunction of the carburetor. Observing our client, the rules remain, you can simply do these works with your own hands.

What, in fact, how to repair the Partner 350 chainsaw is in charge of our next article.

If the tool does not start, then the discrepancy is hidden in the trigger mechanism differently in the ignition system. Then, if the starting device is working properly, then you need to painstakingly examine the candle. It must be turned out and painstakingly examined.

Advantages and disadvantages

Zama carburettors are very reliable and easy to operate. Specifically, a carburetor is installed on the STIHL 180 chainsaw, on which there are no screws for adjusting the quality and amount of the mixture, as we are used to. One screw greatly simplifies adjustment.

The diaphragm carburetor has no significant drawbacks. With such a carburetor, the chainsaw works in any position. For side sawing, vertical, etc.

Despite the aforementioned advantages, the carburetor is sensitive to fuel quality. In addition to clean air from the air filter, the carburetor needs to be supplied with clean fuel from the gas tank. But this is not always possible, therefore, at least once every six months, it must be cleaned and blown through.

STIHL 180 chainsaw carburetor: DIY adjustment, repair, device

The STIHL 180 chainsaw (aka STIHL MS 180) is the most popular and recognizable model of the German brand. This chainsaw is simple and reliable in operation. The only component that requires close attention is the carburetor. This article will discuss carburetor adjustment, repair and maintenance.

Read more:  What a Goodluck Chainsaw Tire

When to adjust the STIHL 180 carburetor

First, it is worth deciding why it may even be necessary to adjust and repair the STIHL ms 180 carburetor. So, this must be done in the following cases:

  • if the chainsaw does not idle;
  • repairs may be required if the saw does not start;
  • there is a loss of power;
  • increased fuel consumption;
  • the chainsaw does not develop maximum speed.
  • stalls when accelerating.

This list can be continued for a long time, but we have identified the main reasons. Before proceeding with the adjustment, you need to know what are the main parts of the carburetor on the STIHL 180 chainsaw, and who makes it.

How the STIHL 180 carburetor works: device, principle of operation

The main components of the STIHL 180 chainsaw carburetor are the following:

  • fuel pump (with internal diaphragm);
  • main (membrane) chamber;
  • diffuser;
  • throttle and air dampers;
  • needle valve;
  • fuel jets;
  • nozzle with valve;
  • idle speed adjusting screw.

The principle of operation is as follows. The chainsaw crankcase is connected to the fuel pump in the carburetor by a special channel. Due to the alternating piston stroke, a vacuum is created in the engine crankcase. Due to this, the diaphragm in the fuel pump rises and the valve opens to supply fuel to the carburetor.

Further, the fuel passes the filter element (mesh) and through a special channel enters the main chamber. A control diaphragm is installed in this chamber, which regulates the fuel supply by pressing the rocker arm, which in turn lowers the needle valve.

The vacuum generated in the carburetor diffuser by turning the air throttle valves is responsible for raising the control diaphragm. As soon as the engine starts, the mixture must be leaner. We lower the air damper, the vacuum in the diffuser is minimal, the membrane falls into place.

From the main chamber, fuel enters the diffuser using a nozzle with a check valve, or through the idle nozzles (when the gas throttle is closed). There it is mixed with the intake air and the already prepared mixture enters the engine cylinder. A check valve prevents air from the diffuser from entering the main chamber.

Adjusting the carburetor of the STIHL 180 chainsaw

Usually, special screws are responsible for the quantity and quality of the fuel entering the diffuser, by adjusting which we change the cross-section of the fuel channel. But on the used carburetor of the STIHL 180 chainsaw, to facilitate the operation of the saw, these two screws are missing.

The channels are designed in such a way that the optimal amount of fuel enters the diffuser at all engine speeds. And here the LD screw is responsible for the adjustment, the rotation of which regulates the air supply to the idle jet. How does the engine speed change?

So, to adjust the carburetor of the STIHL 180 chainsaw, you need a regular flathead screwdriver and an electronic tachometer (optional). The adjustment algorithm is as follows:

  • Check the air filter. If necessary, replace the filter element.
  • Tighten the LD screw counterclockwise to the end, and then unscrew it 2 turns. Attention, the thread is left! To access the screw, a screwdriver hole is provided on the saw body. Start the engine and warm up for 5-7 minutes.
  • Turning the LD screw slowly clockwise, freely adjust the idle speed. 2 situations are possible:
  • The engine idle speed is very low. The engine does not keep idling. Turn the LD screw until the saw starts to rotate, and then turn the screw 1/2 back (the chain should stop).
  • The saw is spinning at idle speed. In this case, slowly turn the screw counterclockwise until the chain stops, then turn the screw another 1/2 turn in the same direction.

If, after all manipulations with the carburetor settings, the chain continues to spin at idle speed, the saw must be returned to the dealer for a service center.

штиль 180 штиль 170 регулировка карбюратора регулировка холостого хода

The video below shows a detailed adjustment of the carburetor of the STIHL 180 chainsaw using an electronic tachometer.

STIHL 180 chainsaw carburetor repair

The main malfunctions of the carburetor of the STIHL 180 chainsaw include the following.

  • Gasoline is not supplied to the carburetor. A commonplace reason is the failure of the fuel pump. The diaphragm has lost its elasticity or is leaky. This happens due to material fatigue with prolonged use. As a result, when the engine is under vacuum, the diaphragm does not rise and does not open the fuel channel with the valve. It can be replaced with a spare one from the repair kit by disassembling the carburetor.
  • Gasoline may also not flow due to a clogged filter element (mesh) in the channel between the fuel pump and the needle valve. It is also treated by replacing from the repair kit.
  • The carburetor is overflowing. It’s not hard to guess that the problem lies in the main camera. Dirt particles get into the cavity between the needle and the channel, i.e. the valve does not completely close the channel when needed and the chamber is flooded. Very often the membrane stops performing its function due to stretching (natural wear). As a result, when lowering, the diaphragm does not fully raise the needle, and fuel continues to flow. The main membrane is also included in the repair kit. Replacing it is not difficult.
  • Owners of STIHL 180 chainsaws often find it difficult to start after a winter standstill. In this case, there is a sticking of the valve in the nozzle. The manufacturer recommends burning the remaining gasoline in the carburetor before storing the chainsaw. Gasoline tends to evaporate and during long storage, engine oil remains in the carburetor, upon contact with which the injector valve begins to stick to the body. As a result, no fuel flows into the diffuser. Since the nozzle is not part of the repair kit, you have to knock it out and rinse it thoroughly. This must be done very carefully.
  • If the idle jet or nozzle is clogged, it is enough to blow them with compressed air. Or rinse in gasoline, in 90% of cases it helps. But you cannot use needles or wires, because there is a risk of changing the flow area, thereby changing the throughput of the nozzles.

A common problem due to which the STIHL 180 is unstable is the loss of a retaining ring on the throttle shaft, as a result, it begins to wobble and play, which in turn leads to interruptions in operation.

So, you’ve decided to remove the carburetor and diagnose it. The withdrawal procedure is as follows:

  • Push the throttle trigger and lower the choke lever down. We turn the latch and remove the cover of the chainsaw.
  • We unscrew both fastening nuts with an 8 socket wrench and remove the air filter with the housing.
  • We remove the gas thrust (throttle valve) of the carburetor.
  • Disconnect the cable from the control lever
  • We take out the engine control lever from its place. In parallel, we disconnect the air damper rod.
  • Pulling the carburetor towards you, remove it from the studs. Do not forget to disconnect the fuel supply hose.
Read more:  Chainsaw attachment for cutting metal

A more detailed and visual algorithm for dismantling the carburetor from the chainsaw is presented in the video.

As for disassembling the carburetor of the STIHL 180 chainsaw, everything is simple. 1 bolt is unscrewed on the fuel pump cover and 4 bolts on the main chamber cover. This is enough to change all the necessary components from the repair kit.

After disassembly, the carburetor must be rinsed in gasoline, and the channels and nozzles must be blown out with compressed air. Under no circumstances should the carburetor be blown out under high pressure and in the assembled state. Otherwise, you can stretch the membrane or diaphragm. Carburetor stops working properly.

In order to assess the condition of the filter mesh and membrane, you need to perform the following sequence of actions:

  • Unscrew the screw.
  • We assess the condition of the membranes, remove dust and dirt, and, if necessary, replace the membrane with a new one. Everything must be clean under the membrane The membrane must also be free of dirt
  • We check the condition of the filter mesh for dirt, if any, clean it.
  • Putting everything back and disassembling the carburetor from the other side. Having unscrewed 4 bolts, remove the cover, remove the membrane and assess the condition of the insides. In total, you need to unscrew 4 screws
  • To check the correctness of the fuel supply by putting the hose on the fitting.
  • We blow into it with our mouth, while opening the needle valve with our fingers, everything should work clearly.
  • We blow out 2 holes in the nozzles with the same hose, they should puff out calmly, without excessive effort. If necessary, it is enough to clean it with a conventional cleaner WD-40.
  • Remove the jet-nozzle located on the right and clean it with a thin wire from the back side.
  • We clean and collect everything. When installing the cover, be sure to fit it correctly. See the photo below.
  • As for the STIHL 180 carburetor repair kit, it includes a set of gaskets for covers, a diaphragm and a membrane, a needle valve, a rocker arm with an axle and a spring.

    STIHL 180 chainsaw carburetor: DIY adjustment, repair, device

    The STIHL 180 chainsaw (aka STIHL MS 180) is the most popular and recognizable model of the German brand. This chainsaw is simple and reliable in operation. The only component that requires close attention is the carburetor. This article will discuss carburetor adjustment, repair and maintenance.

    What carburetor is used on the STIHL 180 chainsaw

    The STIHL 180 chainsaw is equipped with a Japanese membrane-type Zama carburetor. Some users are confused by the China inscription on the carburetor. Yes, indeed they are going to China. But the plant is owned by STIHL (STIHL) and the quality remains high. However, there are also Chinese copies of the chainsaw with the corresponding carburetors. But these saws are usually cheaper than the original.

    Advantages and disadvantages

    Zama carburettors are very reliable and easy to operate. Specifically, a carburetor is installed on the STIHL 180 chainsaw, on which there are no screws for adjusting the quality and amount of the mixture, as we are used to. One screw greatly simplifies adjustment.

    The diaphragm carburetor has no significant drawbacks. With such a carburetor, the chainsaw works in any position. For side sawing, vertical, etc.

    Despite the aforementioned advantages, the carburetor is sensitive to fuel quality. In addition to clean air from the air filter, the carburetor needs to be supplied with clean fuel from the gas tank. But this is not always possible, therefore, at least once every six months, it must be cleaned and blown through.

    How much does a new carburetor cost

    STIHL 180 chainsaws are in great demand in Russia, primarily due to their reliability. The carburetor is no exception and is also quite reliable and unpretentious. Adjustment or repair of the carburetor is required only after long-term operation, not less than 5-7 years (at average workload). The tuning process itself is simplified as much as possible by STIHL engineers, this is the first chainsaw in which only one screw is provided for adjustment.

    adjust, carburetor, stihl, chainsaw