How to remove the carburetor from a Partner chain saw

The carburetor on the Partner 350: adjustment, construction, and repair

When performing construction and repair work in the countryside, it is impossible to do without the use of a gasoline saw. The same can be said for gardening. In case of failure of this tool, all work will stop, so it is very important to be able to troubleshoot. With some experience, you can adjust the carburetor yourself. Although the procedure is quite complicated, it can be learned by anyone, if they have the desire.

The Partner 350 stands out with its excellent selection of components and high quality build. The basis of the garden tool is a 2-stroke 1-cylinder engine that runs on a mixture of gasoline AI-92 and motor oil. The engine piston group is forged and coated with a chromium alloy to prolong the life of the engine. The device of the factory engine includes a proprietary filter CCS, distinguished by the ability to trap the smallest foreign particles, not allowing them into the fuel.

The Partner 350 chain saw has easier starting than competitive models because of its improved starter motor with self-cleaning cylinder, professional fuel pump, and long-life electronic ignition. To pre-pump the fuel used in the cylinder, the model is equipped with a primer.

For the safety of the operator during the operation of the working chainsaw Partner equipped garden tool quality inertia brake, immediately triggered when the saw headset on a nail or any other foreign object.

Partner Saw’s Uses. Metal bar and chain. They can be tightened with two wrenches without having to remove the protective cover of the plastic housing.

One of the great advantages of the Partner 350 chain saw is the clever layout of the controls. The throttle trigger, recoil switch, and recoil starter cord are located on the rear of the machine, making it easy to operate in confined spaces.

How to Clean a Chainsaw Carburetor?

To flush or clean the carburetor, the chainsaw carburetor must be removed and disassembled. Before cleaning it is necessary to prepare in advance all the necessary things: two screwdrivers (plus and minus), wrenches, but better a head with nozzle, clean rags, special cleaner, pump and ultrasonic cleaner (recommended). Before you start cleaning, you need to drain all the gasoline. this is a must. Once the residual fuel is drained and all the tools are prepared, we proceed to cleaning:

  • Disconnect the top cover and remove it.
  • Carefully remove the fuel pump diaphragm.
  • On the left side of the housing you will find the spring clip. Once they are disconnected, under the brackets you can see the screws. they also need to be unscrewed.
  • Unscrew the bottom cover.
  • Remove the screw and you have access to the needle valve. It and the spring located underneath it should be carefully removed so as not to blunt the needle.
  • The air damper is disassembled with a little bit of force longitudinally, and then the damper axle is removed.
  • The last thing to remove is the throttle, lever and axle.

After the carburetor is disassembled, all the parts should be placed on a flat surface on a clean rag. Carefully inspect each part for clogging or wear. Pay special attention to the nozzles and inlet connection. Their clogging. the main reason why there is no gasoline in the carburetor of a chainsaw.

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If for any part you can see that it is badly worn, it is better to replace it immediately with a new one, so that in the future you will not think again about how to repair the carburetor of a chainsaw. Cleaning the carburetor of a chainsaw with your own hands is made with a special detergent. Rinse each part well and then dry it with a lint free cloth or better with compressed air. All channels are also blown with air.

If there is an ultrasonic cleaner on hand, this is even better. Fill a tub with diesel fuel, put the contaminated parts in it gently for 5-10 minutes and dry them with compressed air after cleaning.

Reassembly is performed in the reverse order. A very important point is the installation of the needle valve. it must rotate freely in the seat. If the blade gets stuck, push it in slightly or apply pressure to bring it in deeper.

It is strongly recommended to wait for 20-24 hours after cleaning. it is necessary for the cleaning agent to fully evaporate. Otherwise it would mix with the fuel-air mixture and get into the cylinder, leaving a residue on the walls after combustion.

Partner chain saws are a great example of a real quality product at a low price. The range of chainsaws from Partner is really huge, allowing you to choose a model with the right features to suit every buyer.

Assembly of the carburetor

The carburetor housing on the Partner 340 chain saw is made of aluminum alloy. It has process channels through which the fuel-oil mixture moves and a diffuser. The task of the latter is to mix air with gasoline, thereby forming a combustible mixture.

The main elements of the carburetor include:

  • fuel pump;
  • main chamber with diaphragm;
  • throttle valve and air valve;
  • screws (quality, quantity, idle speed adjustment);
  • needle valve;
  • fuel injectors.

Lubrication system device

Depending on the brand of chainsaw, the details of the lubrication system may vary slightly structurally, but their overall number and connection scheme remains the same.

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The main components of the lubrication system are:

  • the oil tank, usually located in the engine crankcase.
  • Filter element installed in the tank.
  • Lube line, it is a small diameter hose made of oil-resistant rubber.
  • The heart of the system is the oil pump.
  • Gear of worm gear transmitting power from engine to pump.
  • The chainsaw bar, it can also be considered an element of the lubrication system, because it has special holes for oil supply, by the way, and the chain itself is involved in the transportation of oil and, accordingly, also has some elements designed specifically to provide lubrication.

Partner chainsaw repair carburetor with their own hands

Detail: chainsaw Partner carburetor repair with his own hands from the real master for the site

For people involved in construction or logging, as well as those who live in their own home with an adjacent plot of land, it will be very helpful to own a quality Swedish chainsaw “Partner 350″, which is a great substitute for other tools for cutting wood, such as two-handed saws or hacksaws.

As with any other machine, chainsaws also require careful attention and periodic maintenance or they will break down quickly as a result of use. At the same time, asking qualified specialists to fix your chainsaw costs money, which you may not want to spend for any reason, because you understand that most of the faults and failures you can fix yourself. To do this, you need to understand the structure of the chainsaw and watch the video, where you will get detailed instructions for the repair of the chainsaw “Partner 350″.

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The vast majority of product failures are due to problems in the engine and related systems. Usually to repair the unit should be carried out its disassembly. To make sure you don’t make a mistake when disassembling your chain saw, take a look at the chainsaw’s construction in the instruction manual or video.

When your chainsaw does not start, you should first look to see if the spark plugs are serviceable, which gives a spark that ignites the fuel and pulses the piston, which performs useful work.

In order to assess the condition of the spark plug, you need to remove the wire going to it from the starter, and unscrew it with a suitably sized wrench from the groove. Inspect the spark plug: its appearance will tell you what’s wrong with the chainsaw:

The consequence of such malfunctions is the inability of the fuel to penetrate into the cylinder and begin to perform useful work in rotating the chain, so the chainsaw will not start. The causes may be as follows:

  • The fuel filter has failed because it is clogged.
  • The breather is clogged (this is the name of the hole made by the manufacturer in the gas tank and designed for the flow of air into the tank through it).
  • Lack of fuel in the gas tank.
  • The diaphragm in the carburettor is not intact or there is very likely a clog in the carburettor passages.
  • Carburetor not adjusted properly.

To determine if the breather plug or filter is clogged with foreign matter, you will need to disconnect the fuel hose from its mounting and see if gasoline is leaking from it and at what pressure. If gasoline is leaking slowly and weakly, clean the breather plug with a sharp object such as an awl. If the filter is the problem, take it out of the tank where the fuel is stored and clean it, and replace it if necessary.

You have discovered that the carburetor is the cause of your problem? The good news here is that if the filter on your carburetor gets clogged, you can easily clean it yourself. In addition, you will make the adjustment and adjustment of the carburetor of the chainsaw “Partner 350” with your own hands without any problems, if you strictly follow the recommendations from the instruction manual.

The bad news is that you are unlikely to cope with another, more complicated carburetor repair with your own hands, and you will have to take your unit to the mechanics. Sometimes the manufacturer deliberately does not write in the instructions how to make adjustments and repair the carburetor, so that people who do not understand the device of the product, do not try to fix the problem themselves in case the chainsaw suddenly stopped starting, and as a result did not break the unit permanently.

Major breakdowns of this chainsaw system include:

  • Low pressure detected by the compression gauge in the cylinders, which causes the engine to lose power and cannot rotate the chain at the speed needed to cut the wood effectively. The pressure at which the engine runs smoothly is about nine atmospheres.
  • Failure of the rings in the pistons to seal, causing red-hot gases from the cylinders to enter the crankcase. The problem can be solved by replacing the rings.
  • Problems with tightness of the gaskets located in the cylinder head (CGB). Visually, they are manifested as combustion products of gasoline through gaskets and engine pressure drop. The problem can be solved by replacing the gaskets.

If you want to know if there are problems in the cylinders, the easiest way to do it is to remove the muffler and assess the situation by looking through the hole left from the removed muffler at the inside of the cylinders. In the event of a need for repair you would, of course, need to remove the cylinder head to gain access to the pistons and cylinders.

How a chainsaw carburetor works. How the carburetor works and how it works

Let’s find out how a chainsaw carburetor works. This device consists of:

  • housing;
  • the diffuser, which is located at the inlet of the unit;
  • nozzles;
  • valves that regulate the mixture supply;
  • of a special atomizer;
  • float chamber.

There are 2 or 3 adjusting screws equipped with springs. There are cone needles at the end of the screws.

  • When you turn on the motor, the air damper is swung open.
  • The air moves forward and mixes with the fuel in the diffuser, where the passage narrows.
  • The air goes through the nozzles, is then cleaned by the filter and enters through the flap located at the inlet of the diffuser.
  • A special flap, which is located behind the diffuser, distributes the mixture and it enters the combustion chamber.

The device is arranged in such a way that the volume of fuel that passes through the nozzles is regulated by the screws of the chainsaw. the volume of fuel in the chamber depends on the sharp cone valve. This valve is controlled by a diaphragm that controls the flow of compressed air into the chamber. The operation of these units depends on the rotation of the engine. The mixture is cleaned with the help of a filter.

Problems with the chain

How to adjust the plastic door yourself

To control the chain, a special catcher is used, which also has a chainsaw “Partner 350”. Failures of this type are the result of improper operation of the device. The chain can sag over time as a result. If this is the case, you need to start with a sprocket inspection to repair the saw. It is located near the handle. There is no need to remove it in this case. If the sprocket teeth are not deformed, you can simply try to lubricate them with machine oil.

Next, it is important to inspect the catcher. The device is quite simple and represents a set of rollers

When the catcher fails, they are knocked out of the circuit. It is impossible to fix them by yourself. The only option is to put a new catcher. To do this, a screwdriver is used. It is fixed with three nuts

When installing the catcher, note that the rollers are located at the top and must be near the chain

Operation of the carburetor

When starting the engine, the air damper is closed. In this mode a rich mixture is formed. The engine gradually warms up:

  • The cylinder walls get hot.
  • Heat is transferred to the fuel chamber, the temperature of the fuel increases, which improves its evaporation during external mixing.

The filter elements keep the abrasive particles in the ambient air out of the cylinder.

  • After warming up you can open the choke. For stable operation is responsible for the correct adjustment of the idle speed.
  • The air moves at high velocity through a tapered nozzle. The fuel leaks into the nozzle, it evaporates and the mixture starts to run.
  • Opening the throttle increases the amount of charge.
  • RPMs increase. power and torque.
  • By closing the throttle, charge flow is reduced. Power goes down.
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There are adjustment screws for adjusting the carburetor and they are located on the control panel. Operating mode is set by the position of the levers associated with the damper and throttle. Cables are attached for ease of operation.


The Partner 351 saw has good power and performance despite its compact size and weight of 4.7 kg:

  • 1400 W motor power (1,9 l.с.);
  • 35 cm bar. It is possible to install a 41 cm bar;
  • 56-link chain with 3/8-inch pitch;
  • The spark plug is Bosch WSR 6F;
  • Fuel tank capacity of 380 gr;
  • 200g oil tank;
  • Noise level of just over 100 dB.

CCS-powered air filter contributes to significantly reduced fuel consumption. Dual air-cleaning system increases life of your Partner 351 chain saw motor. The chain is running at high RPM.

Well thought out ergonomics and reliable vibration damping system allows you to use the tool for hours without interruption.

The chain brake activates immediately, making your chainsaw even safer and more comfortable to use.

Adjusting your Partner 350 Carburetor by yourself

Before you start adjusting your Partner 350 chain saw it’s important to keep the carburetor area free of dirt and dust.

The easiest way to clean your chainsaw of small chips is to use a compressor with a blow gun or nozzle on it.

First step in adjustment

The Partner 350 has openings on the left side of the top cover that give you access to the adjustment screws, but if you’re making this adjustment for the first time, you might want to remove the top cover. It’s more convenient this way, because it’s the easiest way to clean a chainsaw. к. you can see where the heads of the adjusting screws are.

Then, it is necessary to set the quality and quantity screws to the fully tightened position and then loosen them by 1/5 of a turn.

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If you adjust with the cap off, remember that the left screw is the quantity screw, respectively the right one is the quality screw. In order to make it easier, the manufacturer marks the carburettor body, under each of the screws with (L) and (H). (L). quantity. In some manuals it is also called the screw, which is responsible for low and medium rpm traction. (H). fuel quality, adjusts the number of maximum revolutions.

Also, there is a third adjusting screw on the carburetor, which is designated by the letter (T). It is needed to adjust the throttle position in idle mode.

Tip: If for some reason there are no markings on the carburettor adjustment screws, you can distinguish the screw (T) by a spring installed on it, which is necessary to prevent spontaneous unscrewing during operation. It also has a Phillips-head screwdriver head.

Second step

After setting the screws in the desired position, the Partner 350 chain saw should be started and let it run for a few minutes, i.e. к. Adjustment should be done on a hot engine. As soon as the cylinder becomes warm, you can proceed to adjusting the quantity screw, for this you must turn it clockwise, until the engine starts to produce maximum revolutions, then immediately turn the screw back one-quarter turn.

In this position (L), the saw should work reliably at idle speed. If the idle speed is too high or too low, adjust the idle speed with the choke position screw (T).

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Set the maximum rpm with the choke adjustment screw.

Important: remember that the correct adjustment of the maximum engine speed is only possible with a tachometer. You can only get an approximate idea of the RPM. Exceeding the maximum engine speed will inevitably lead to scoring of the cylinder and premature destruction of the bearings of the crankshaft, connecting rod.

According to the specifications of the Partner 350, it can be set to a maximum of 12500 rpm.

Adjustment without tachometer

When adjusting the carburetor without the tachometer, check the sound and emissions of the chain saw. If the saw smokes a lot, it is a sign of improper adjustment. To fix it, turn the adjustment screw (L) back a little. If you can’t get the maximum rpm on your chainsaw right away, but it still works well at idle, turn the screw (H) until the chainsaw just begins to move freely and you can feel the engine rpm at full throttle.

The video below provides instructions on how to independently adjust the carburetor of the Partner 350 saw without using a tachometer. This video shows not a professional craftsman, but an ordinary user who, using the right algorithm, adjusted his chainsaw qualitatively.

Basic troubleshooting and error correction

For one reason or another, the tool may fail. Before you disassemble the chainsaw, you need to prepare. After all, it is not enough to repair a chainsaw with your hands alone, you will need locksmith tools.

Usually the chainsaw does not start for 2 reasons: the lack of spark and problems with fuel flow from the carburetor into the cylinder. This can manifest itself in this way: the chainsaw will not start or works irregularly. When the revolutions are increased, it stalls.

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First we clean dust and dirt from the outer casing. After that we remove the cover and clean the inside surface. Unscrew the spark plug, clean it, check the gap between the electrodes. If necessary, we make the adjustment of the gap. Pull the wire on the spark plug and bring it to the body and pull the starter. If you see a spark, the ignition system is fine. If necessary, you can replace the spark plug. Along with the spark plug it is necessary to check and clean the fuel filter. After reassembly the saw should start.

The next problem is the carburettor malfunction. Often this occurs from engine vibration after a long run. The carburettor needs to be readjusted. There are 3 regulating screws: S (idle speed), H (maximum revolutions), L (minimum revolutions).Set them according to the instruction.

These are the two main reasons that affect the start and operation of the chainsaw. It is not necessary to disassemble the chainsaw completely to fix them. Other types of troubleshooting require considerable skills, for example, everyone can disassemble the carburetor, but assemble it is not. Complete disassembly and elimination of other problems is better to be entrusted to professionals. Sometimes you need specialized wrenches that are not included with conventional locksmith tools. Buying them can be more costly than going to a repair center.

Overall, the chainsaw is pretty good. Reliable enough chainsaw with proper use and timely prevention.

How to tune a Partner 350 carburetor chainsaw

Carrying out repairs and construction of the country can not do without the use of a chainsaw, this is true even when taking care of the garden. If the tool is faulty, it will cause all the work, so it is important to have self-testing and troubleshooting skills. If you have some experience, you can make adjustments to the carburetor, this procedure is complicated, although it is quite possible.

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Repair of the carburetor chainsaw Partner 350 with their own hands

In detail: repair the carburetor chainsaw Partner 350 with their own hands from a real master for the site

A chainsaw is also needed in construction, gardening and landscaping. its presence greatly simplifies the performance of a number of woodworking tasks. The main node of this tool is the engine, the operation of which depends largely on the condition and settings of the carburetor. This is where the fuel mixture is prepared. So if the saw won’t start, stops, or doesn’t deliver the power it should, it’s probably because the carburetor isn’t working properly. Fortunately, it is possible to cope with this in many cases on your own. Only for this you need to know and understand the construction and principle of work of this unit, and, of course, the chainsaw itself.

The main purpose of the carburetor is to mix fuel with air in the necessary proportions. If the latter are disturbed, it has an almost immediate effect on engine operation.

STIHL MS 181 C BE chain saw carburetor

Chainsaw carburetors may differ in design. Their basic components and principle of operation, however, remain more or less the same.

The air inlet is controlled by a wind tunnel with an air inlet flap across the tunnel.

This part is where the base tube is drained. this is where the airflow rate increases, t.е. air is always supplied to the carburetor under some pressure.

This is where the fuel comes in contact with the air flow. Fuel goes to the atomizer from the float chamber through the nozzle.

This is the reservoir that keeps the fuel mixture stable.

Constructional diagram of a chainsaw carburetor

The chainsaw carburetor works according to the following principle:

  • when the engine is started, the main flap opens and a jet of air is fed into the air duct at a certain speed;
  • the air flow rate as well as the float level in the chamber are regulated by the position of the flap, namely by the pressure difference in the float chamber and the air channel;
  • fuel is sucked from the float chamber to the nozzle and from there to the diffuser;
  • passing through the diffuser, the air captures the fuel that comes in;
  • The resulting mixture is fed into the cylinder cavities through the intake ducts.

The pressure in the float chamber is approximately equal to atmospheric pressure, but there is a vacuum in the carburetor air ducts when starting the chainsaw engine. Opening the flap leads to an increase in the intensity of the air supply. As a result, more fuel goes into the carburetor and the engine speed increases.

During the first hours of work, the 2-stroke chainsaw engine requires running-in, on which the quality of its further work depends. During the running-in period, the primary carburetor adjustment is performed. the optimum parameters for fuel mixture preparation and supply are set.

Initial running-in of a chainsaw: Working with thin material

Most modern chain saws come on the market with settings. Nevertheless, it does not hurt to check the quality of the factory settings. after all, you will have to work with the tool.

The first time you start your chainsaw, it should run sparingly. For several hours after starting it is therefore recommended not to overload the engine and to cut only small branches and trunks up to 10 cm thick.

A simple rule of thumb can help protect against chainsaw carburetor malfunctions:

  • Always mix gasoline and oil in accordance with the figures specified by the manufacturer. How much fuel mixture to use on a chainsaw engine
  • Do not prepare the fuel mixture in advance. the properties of gasoline and oil in the mixed state lose their properties over time. The exception is fuel for intensively used tools, but here, too, you should not exceed about a week’s worth of.
  • Use the oil that is compatible with your chainsaw engine. A fuel mixture with an incorrect composition will put it out of action for a long time.
  • When mixing the fuel, be aware of how the climate affects the mix.

The chainsaw must start correctly, provide a stable rotation speed of the sprocket and a smooth increase/decrease in power. There should be no extraneous knocks, pops or noises when the engine is running.

Need for adjustment

To understand how to adjust the gasoline saw “Partner-350”, it is necessary to study the design of this device as much as possible in the first stage. Understanding its principles of operation and familiarity with the specifics of its parts will help determine the cause of the malfunction yourself. The carburetor is one of the main components of the engine. Its purpose is the preparation and further supply of the fuel mixture, consisting of gasoline and oxygen. If the necessary proportions of these ingredients are violated, the engine begins to work incorrectly and subsequently completely fails.

After deciding to tune your Partner-350 saw, the first thing to do is to examine the design features of its parts. The most important component of the system is the diffuser, which serves as a tapering device to increase the flow of supplied oxygen. The diffuser is located right next to the fuel inlet. Flow of incoming oxygen is regulated by a cross-damped tube in the carburetor. Fuel is fed through a nozzle that looks like a needle. The design of the carburetor also provides a float chamber, the purpose of which is to regulate the fuel supply at the inlet to the channel.

How it works

Owners of a Partner 350 gasoline chainsaw may have to readjust the carburetor when using this machine. In order to properly implement this procedure, it is necessary to pay great attention to familiarize yourself with the functioning of this technical element. Fuel is atomized by the air jet in the diffuser and the mixture is injected into the cylinder. The higher the fuel volume, the higher the engine speed. The function of the carburettor in the model described above corresponds to the diagram. Other models use the same pattern.

Owners of a Partner-350 gasoline saw need to adjust the ignition frequently. When the equipment first starts, you should check the idle speed. To do this turn clockwise the screw which is responsible for adjusting the idle speed. After it stops, turn it four and a half turns in the opposite direction. If, after carrying out these operations, the engine does not revolve, you can conclude that there is no problem. If not, you should call for help, because using a chainsaw in this condition can be dangerous.