How to adjust the carburetor on a STIHL 180 chain saw

Carburetor adjustment STIHL 180 with your own hands video

The first thing to know is why you need to have the STIHL ms 180 carburettor adjusted and repaired. What should be done in the following cases:

• If your chain saw does not hold idle speed;
• A repair is needed if the saw won’t start;
• there is a loss of power;
• High fuel consumption;
• The chainsaw does not develop the highest rpm.
• throttles at revs.

the myth list is an option to continue for a long time, alas the main prerequisites we have conditioned. Before you start with the adjustments, it’s good to know what the carburetor on your STIHL 180 chain saw is made of, and who built it.

Operating Tips

The most important thing when using any chainsaw is to change the filter elements on time. It is not necessary to change a chain once in a year or half a year, but change it more often. It’s better to be safe and spend 100 than to crash your tool and pay thousands.

Second, watch the tension of the chain and be sure to loosen it after work, especially in winter.

Third, only work with a sharp chain. If the chain becomes blunt, the sawdust becomes dusty and quickly clogs the air filter, gets into places where it does not need to go, and the ventilation system suffers as a result, the engine overheats. Also due to the lack of necessary resistance, the engine may develop higher revolutions, which is also not good.

How to change the settings, see below for details

STIHL 180 chain saw carburetor, no disassembly, can only be adjusted for idle speed. No special screws can be used to increase or decrease the fuel flow in various settings. The manufacturer limits access to adjustments and does not install these screws. How to adjust the carburetor to the correct idle speed is described in detail in the manufacturer’s manual.

In the case of certain faults, and with experience, you can increase or decrease the fuel supply by increasing the gap in the opening of the needle valve.

To increase the flow, the yoke of the needle valve in the distribution chamber should be bent upwards, and to reduce, downwards. This adjusts the stroke of the needle and therefore the flow capacity of the valve.

Don’t do the adjustment yourself. к. It needs to be done very accurately and if a mistake is made it is almost impossible to return the rocker to its original position.

Let’s consider each malfunction in details

Revolutions are floating at idle

How to understand that the revolutions are floating. The chain saw does not work steadily. It either stops or roars with no load.

One of the most common causes that can occur is a malfunction in the nozzles. They become clogged. The reason jets often go out of order is the bad quality of gasoline and debris that get into the tank at startup. Therefore, first of all, when filling the tank with fuel, it is necessary to use a funnel with a special grid. The mesh keeps debris out of the tank.

Also do not rule out a fault in the fuel system. It is necessary to check the integrity of the hoses, reliable tightening, in order to avoid air suction and gasoline leakage.

You may also want to check the check valve. If it is faulty, it creates a vacuum in the gas tank. Gasoline is leaking and must be replaced by air. If this does not happen, it creates a vacuum. The engine just does not get enough fuel, it starts to stall.

Adjust the air flow in the air distribution chamber with the adjusting screw. If there is not enough air, you get a lean mixture. It enters the combustion chamber, but without air it cannot be ignited. The spark plugs are flooded with gasoline and the chain saw stops.

Your chain saw will not start

There are two possible causes for a chainsaw not starting. It is either not getting enough air or not getting enough fuel. The mixture is either lean or over-enriched. Adjust the fuel mixture quality to correct the problem. How to correctly adjust the carburetor on the STIHL 180 chain saw was explained in the previous section.

Loss of power, high gasoline consumption

Check the fuel system for air leaks. Excessive air in the system leads to an enriched fuel mixture. Check chain tension. A tightened chain increases the pressure on the engine. It is more difficult to do its job.

High gasoline consumption may be caused by fuel leaks. Leaks are easy to see because of oily patches on the chain saw body and tight connections. Seals may need to be replaced. Have this work done by a certified technician.

Structurally the carburetor on the STIHL 180 chain saw is fairly straightforward. The adjustments range is also restricted by the manufacturer. Leaving the only option to adjust idle speed. This procedure does not require special knowledge. An untrained person will not be difficult to correctly and competently adjust the carburetor of a chainsaw on their own.

Let’s discuss each fault in more detail

The rpm is floating at idle

How to understand if revolutions are floating. The chainsaw is not stable. It either stops or roars with no load.

One of the most common causes that can occur is faulty nozzles. Their clogging. The reason why the nozzles fail most often is the poor quality of gasoline and debris that enters, when filling the tank. That is why the first thing to do when filling the fuel tank is to use a funnel with a special mesh. Such screen prevents debris from getting into the tank.

There is also a problem with the fuel system. It is necessary to check the integrity of hoses, reliable tightening, so as to avoid air leaks and gasoline leakage.

It is also worth checking the check valve. If it is faulty, a vacuum is created in the gas tank. Gasoline escapes, air should fill its place. If this does not happen, a vacuum is created. The engine simply doesn’t get enough fuel and stops.

Adjust the air supply to the combustion chamber with the adjustment screw. Not enough air produces a lean mixture. It enters the combustion chamber, but without air the mixture cannot be ignited. No spark plugs in the fuel system, the chain saw stops.

The chainsaw will not start

There are two possible reasons for a chainsaw not starting. It is either not getting enough air or not getting enough fuel. The fuel-air mix is either lean or over-enriched. Adjust the fuel mixture quality to correct the fault. How to correctly adjust the carburetor on the STIHL chain saw 180 was explained in the previous section.

Loss of power, high petrol consumption

Check the fuel system for trapped air. Excess air entering the system leads to an enriched fuel mixture. Check the chain tension on the chain saw. A tightened chain increases the pressure on the engine. It is more difficult to cope with its work.

High gasoline consumption can be caused by fuel leaks. These leaks are easy to spot by greasy oil stains on the chain saw body and at loose connections. Seals may need to be replaced. Have this work done by a STIHL servicing dealer.

The carburetor on the STIHL 180 chain saw is fairly straightforward by design. In addition, the manufacturer has greatly limited the range of possible adjustments. Leaving the only option to adjust the idle speed. This procedure does not require special knowledge. Untrained person will not be difficult to correctly and competently adjust the carburetor of a chainsaw by their own efforts.

Adjusting a Husqvarna chain saw

During the break-in period of the Husqvarna 142, 240, 236, 137 and other similar models the carburetor settings are adjusted in such a way that the engine rpm is 600-700 lower than normal working rpm. If it is not possible to adjust the RPM using the tachometer, the H screw should not be used to override the factory settings.

The manufacturer expressly forbids to exceed the working number of revolutions. When, after adjusting the carburetor, the chainsaw chain is idling, turn the screw T counterclockwise to stop it.

In order to adjust the saw accurately, it is necessary to set it on a flat surface with the bar facing forward. It is also necessary to warm up the engine for at least 12-15 minutes. First you should determine the highest number of idle speed. In order to do that, it is necessary to turn the L screw in clockwise direction and then in the opposite direction on the chainsaw. When the correct frequency is determined, the same screw is turned counter-clockwise from 12 to 25% of its full rotation.

The idle speed in the models of this manufacturer is adjusted with a nozzle with the letter T. The adjustment is made by turning it clockwise until the chain moves. Then turn it counterclockwise until the chain stops moving.

The chainsaw H screw is adjusted correctly only when the saw does not make much noise when the throttle is pressed all the way down and is not weighed down by any load.

If the saw makes too much noise when working and smokes, this nozzle must be turned from left to right to adjust.

Reference!

You may need to adjust the carburetor on your STIHL chain saw if you change the fuel quality, the altitude at which your STIHL chain saw is running (air pressure), or if atmospheric pressure, temperature, and humidity change. Adjusting the carburetor on your chain saw lets you achieve excellent cutting performance in deteriorating ambient conditions. Also the adjustment of the chainsaw carburetor can prevent oil starvation and engine failure due to insufficient lubrication entering the cylinder with a depleted fuel mixture.

Tip: To check the tightness of the engine is very good to use a special device, t.е. a special pump with a pressure gauge. First of all, you have to remove the carburetor on the chainsaw, and install a sealing plate plug on the cylinder inlet window with a flange to connect the hose from the pump. The spark plug can also be sealed with sealant. It is also necessary to remove the muffler and install an airtight plug plate with rubber gasket on the cylinder outlet. Then you have to put the piston in the top dead center and connect the hose from the pump to the flange. Then it is necessary to pump air into the engine up to 0,9 atm. and look at the gauge needle. if it stands on the spot, it means that the engine piston is tight. Then let air out, switch the device (pump) and start pumping air out of the cylinder, creating vacuum in the engine with the pressure gauge reading at.0,5 atm. We look at the arrow of the pressure gauge. if it stands on the spot, then there is no air leakage through the glands or other seals in the engine (which impairs the work of the chainsaw and does not give the opportunity to properly adjust the carburetor of the chainsaw). Thus check the engine for air drainage and compression.

Preparing to adjust the carburetor

The STIHL 250’s top-most adjusting screw, near the muffler, is the most important adjustment screw for adjusting the fuel dosage. The factory setting, the parameters of which are shown on the top plastic cover, stipulates that it must be unscrewed one turn from full twist.

The STIHL 250 chain saw’s carburetor is adjusted with your own hands throughout the operating procedure. Turning the screw up will make the fuel mix richer because the air-fuel mixture gets more gasoline, turning the screw down will make the fuel mix thinner because the air-fuel mixture gets less gasoline.

A carburetor adjustment will not work if there is air intake from the side of the engine through the carburetor:

Your STIHL 250 carburetor should be tuned only after a thorough and thorough check for air leaks. The next stage of preparatory tuning works is complete maintenance of all units and mechanisms.

• cleaning of deposits, slags, resins;
• washing the engine with solvent or acetone;
• replacement of the spark plug;
• cleaning, washing the air filter;
• checking cutting chain tension;
• setting the idle speed;
• warming up the engine to operating temperature.

You can then proceed to the complex manipulation of the tuning.

Throttle adjustment

Tuning a STIHL Saw Carburetor Chainsaw carburetor tuning. Or how not to pay repairmen! Owning a chainsaw in many ways makes life easier even for an amateur, and in some professions this tool is virtually indispensable. However, like any relatively complex device, a chainsaw requires periodic maintenance. Because of untimely or poorly maintained.

How to adjust the carburetor on STIHL 3 Mower carburetor adjustment is done by home mowers, just like all lawn and garden tools, is not a complicated technique in maintenance. It is possible and necessary to fix and adjust it without assistance of others. For example, the adjustment of the lawnmower carburetor in a crude condition. a matter of 5 minutes. The carburetor from the lawnmower is a node in the power system.

How to adjust the carburetor of a STIHL Fs 3 lawn mower lawn mowers, just like all petrol garden tools, are not difficult to maintain. It is possible and necessary to fix, adjust without the help of others. For example, adjustment of the lawnmower carburetor itself. a matter of 5 minutes. The carburetor from a lawn mower is a node in the power system. In a personal computer, as well as all carburetors, goes.

Throttle, installed in the carburetor body and is responsible for increasing the flow of fuel consistency specifically in the cylinder engine. When the throttle is depressed the throttle opening increases the flow capacity of the channel and causes the fuel to rush from the carburettor cavity to the cylinder at a greater volume.

Combustion of a greater volume of fuel, increases the amount of energy produced which affects the power and speed of the processes. The flap is mounted on a shaft passing through the entire carburetor body. At the exit of the shaft from the housing, there is a mount for the throttle cable, beside located cone-shaped adjusting screw responsible for setting the idle speed. By tightening the screw of course slightly to adjust the position of the shaft and a flap attached to it, thus increasing or otherwise reducing the idle stroke, opening or otherwise closing the flap.

Adjusting the carburetor on a STIHL 180 chain saw

Usually special screws are used to control the quantity and quality of fuel flowing into the nozzle. But on the STIHL 180 carburetor that we use, these two screws are missing to make it easier to operate the saw.

The channels are designed so that the optimum quantity of fuel reaches the nozzle at all engine speeds. The LD screw is responsible for adjustment of the idle speed by turning it. What causes the engine RPM to change.

So, to adjust the carburetor STIHL 180 chain saw you will need an ordinary flat screwdriver and an electronic tachometer (optional). The adjustment algorithm is as follows:

• Check the air filter. Replace the filter element if necessary.
• Screw the screw LD counterclockwise to the end, and then unscrew two turns. Warning, left-hand thread! A screwdriver hole is provided on the body of the saw to access the screw. Start the engine and warm it up for 5-7 minutes.
• By turning the LD screw slowly clockwise, we arbitrarily adjust the idle speed. There are 2 possible situations: Idle RPM is very low. Engine speed does not hold idle. Turn the screw LD until the saw begins to rotate, and then turn the screw to 1/2 back (the chain should stop).
• The saw spins at idle speed. If this happens, slowly turn the screw counterclockwise until the chain stops, then turn it another 1/2 turn in the same direction.

If the chain continues to rotate at idle speed after adjusting the carburetor, you should call your STIHL servicing dealer.

The following video shows how to adjust the carburetor of a STIHL 180 chain saw using the electronic tachometer.

Repairing the carburetor on a STIHL 180 chain saw

The main faults of the carburetor of STIHL 180 chain saw can be attributed to the following.

• No gasoline in carburetor. The most common cause is a fuel pump failure. The diaphragm has lost its elasticity or is worn out. This is caused by material fatigue from prolonged use. As a result, when there is vacuum in the engine, the diaphragm does not rise and does not open the fuel channel with the valve. You can replace it with a spare chain from the repair kit by taking apart the carburettor.
• Gasoline can also fail to flow because of a clogged filter element (mesh) in the line between the fuel pump and the needle valve. Also can be treated by changing the valve from the repair kit.
• Carburetor overflows. It is not difficult to guess that the problem lies in the main chamber. Dirt particles get in the cavity between the needle and the channel, i.e.е. The valve doesn’t close completely when needed and the compartment gets flooded. Very often the diaphragm ceases to perform its function due to stretching (natural wear and tear). As a result, when the diaphragm is lowered, the needle is not completely lifted, and fuel continues to arrive. The main diaphragm is also included in the repair kit. It can be easily replaced.
• It is very common to find that STIHL 180 chain saw owners have trouble starting after a winter break. In this case there is a stuck valve in the nozzle. The manufacturer recommends burning off the remaining gasoline in the carburetor before putting the chainsaw into storage. Gasoline tends to evaporate and if stored for a long time, engine oil remains in the carburetor and the injector valve starts to stick to the body when in contact with it. As a result, fuel does not flow into the diffuser. Since the nozzle is not in the repair kit, you have to knock it out and flush it very carefully. You have to be very careful when doing this.
• If the idle speed nozzle or the injector is clogged, it is enough to blow them out with compressed air. Or flushing with petrol, which helps in 90 % of the cases. But no needles or wires should be used.к. there is a risk of changing the passage section, thereby changing the flow capacity of the nozzles.

A frequent problem with the STIHL 180 is that the throttle body loses its retaining ring, which causes it to twist and play, resulting in erratic operation.

So, you have decided to remove the carburettor and make a diagnosis. The order of removal is as follows:

• We press the throttle trigger and lower the choke lever down. Twist off the latch and take off the chain saw cover.
• Loosen both nuts with an 8 mm socket wrench and take off the air filter and its housing.
• Remove carburetor throttle rod.
• Disconnect cable from control lever
• Pull out the engine control lever from its place. At the same time we disconnect the choke rod.
• Pulling the carburetor toward us, we remove it from the pins. Don’t forget to disconnect the fuel hose.

A more detailed and illustrative algorithm of carburetor disassembling from a chainsaw is presented on video.

Disassembling the carburetor on the STIHL 180 chain saw is as easy as it gets. Remove 1 bolt on the fuel pump cover and 4 bolts on the main chamber cover. This is enough to change all the necessary components in the repair kit.

After disassembly, the carburetor should be washed in gasoline, and the channels and jets should be blown with compressed air. Under no circumstances should the carburetor be blown at high pressure and assembled. Otherwise you can stretch the diaphragm or diaphragm. The carburetor will stop working properly.

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

Everything under the diaphragm should be clear

There must not be any dirt on the diaphragm either

You need to unscrew 4 screws in total

The carburetor repair kit for the STIHL 180 includes a cover gasket kit, diaphragm and diaphragm, needle valve, rocker arm with axle and spring.

The reliability of the Chinese carburetors, bought on Aliexpress

The 21st century has allowed people to shop from great distances. It’s very convenient. order a product at one of the sites and in a few weeks you have it in your hands. One such service is Aliexpress. There you can buy a variety of products, including a carburetor for your saw from China. But what a quality product? Surprisingly, but not worse than domestic. For most parameters they are close to their Russian counterparts, so this purchase will not disappoint chainsaw owners. Relatively inexpensive and of high quality. you’ll love it!

In conclusion, I would say that STIHL-built carburetors from STIHL are probably the most rugged and reliable. If you want your tool to work properly for a long time, you should take care of it. Don’t forget to clean the air filter and lubricate the chain with a tested oil at all times. When storing the saw for a long time, be sure to remove all gasoline and chain oil from the tank.

Have fun working with wood and don’t let your iron friend break down!

How to Check a Gas Saw’s Carburetor?

After adjusting, check acceleration, maximum rpm and engine idle speed. When checking the first parameter, you should sharply pull the throttle trigger. If the engine does not start to revolve, turn the “L” screw counterclockwise. One turn may not exceed 1/8 of a full circle of the propeller.

To measure the maximum rpm you need to use the “H” screw. To increase the maximum RPM, turn the screw clockwise. To decrease the RPM the screw should be turned in the opposite direction. Remember that the maximum speed should not exceed 15 thousand rpm.

For a final check of the chainsaw when idling, start it up and place it on a level surface. Let the motor warm up and pay attention to the following elements of the chainsaw:

• The chain must not move;
• engine. when the throttle trigger is pulled, the engine should rev steadily up to and including the set maximum rpm.

Important hint. if the carburetor is adjusted correctly, the sound of the chainsaw motor will strongly resemble the sound of a 4-stroke engine.

The carburetor of a Chinese chainsaw is adjusted and checked in a similar manner. The only difference is that the process of tuning such tools can take much more time. on average, about an hour. In addition, you should remember that the adjustment of Chinese chainsaws is required much more often. often it must be done immediately after the running-in of a new tool.

How much is a new carburetor

The question is whether they are original carburettors. From online stores

STIHL 180 chain saws are in high demand in Russia, primarily because of their reliability. The carburettor is no exception and is also quite reliable and unpretentious. Adjustment or repair of the carburettor is required only after prolonged use, at least after 5-7 years (at average load). STIHL engineers made the adjustment procedure as easy as possible: this is the first chain saw with only one screw for adjustment.

Algorithm of removal and installation

If you need to clean the carburetor STIHL 180 or disassemble it, first you need to remove the unit from the chain saw. This must be done in accordance with a certain algorithm of actions:

• Put the chainsaw cover on the guide bar.
• Remove the top cover of the chain saw.
• Remove the two nuts that hold the air cleaner and carburetor.
• Remove the air filter housing.
• Disconnect the cable from the engine control lever.
• Carefully remove the lever from its seat in the housing while disconnecting the air damper rod from it.
• Pull the carburetor toward you and disconnect the fuel supply and the throttle link.

Reattach the part by reversing the procedure.

When removing and installing the chain saw’s engine control lever, you must be extremely careful, t. к. the seat on the carburetor is the weak link in the chain saw and is often broken by inexperienced users.

Disassembling a STIHL 180 carburetor

In order to blow, change gaskets or needle valve, the carburetor must be disassembled. To do this, loosen the four screws on the compensator cap and one on the fuel pump.

Once the cuticle is open, you have to be very careful. к. Debris in the carburetor will make it impossible to operate. Its channel thickness is comparable to the thickness of a thread or even a human hair.