Tuning The Carburetor Of The Partner Chainsaw

Adjusting the carburetor of the Partner 350 chainsaw

This is the most frequently performed self-service maintenance procedure for your chainsaw and is worth learning. It is similar to adjusting the carburetors of most chainsaws and is described in sufficient detail in the proposed:

It is important to complete it by adjusting the idle screw, which ensures the immobility of the chain when operating in this mode. If the chain does NOT stop at the lowest steady speed, this indicates that the clutch needs to be repaired and the saw is unsafe to use.

Chainsaw Partner 350: malfunctions and their elimination

One of the main features of this saw, its users note the durability of operation with a minimum number of failures. And yet they do happen. To determine why the saw stopped working, you need to make an elementary diagnosis.

If the saw Won’t start, then:

  • There is no spark on the candle;
  • Fuel is NOT supplied;
  • NO air coming in.

First, check for the presence of a spark: unscrew the spark plug, attach it to the high-voltage wire and put it on the cylinder, pull the starter. If there is a spark, then clean and adjust the gap on the spark plug (0.5. 0.65 mm). If it is not there, then you need to change: either the flywheel or the coil (magneto). In addition, the candle itself may fail or the high-voltage wire may break.

Tuning The Carburetor Of The Partner Chainsaw

The next step is to check the fuel supply. To do this, disconnect the supply hose from the carburetor and check for its presence. Absence may mean that the fuel filter or supply system is forgotten. And the carburetor itself may become clogged.

If you are NOT experienced in repairing and cleaning it. Entrust this work to specialists.

If the air supply deteriorates, the saw should start, but it will not work well. Remove and wash the air filter. Put it back in place only after it is completely dry.

If the saw starts well, runs at idle and stalls when gas is applied. The muffler is most likely clogged. Take off, disassemble, wash, put in place and work further.

Easily do it yourself, you can also change the tire and chain, carburetor, starter, oil pump, ignition and clutch.

Here is a complete disassembly of this saw:

And you will be quite capable of replacing the torn starter cable after watching this:

We recommend that you entrust more complex chainsaw repairs related to replacing the cylinder-piston group or crankshaft with specialists, although if you are familiar with two-stroke engines, then this work will NOT be difficult for you, but spare parts for Partner chainsaws. Not a deficit.

To enlarge a picture, click on its thumbnail.

We advise you to regularly monitor the serviceability of the safety group: brake and chain catcher. Remember that dust should be thoroughly cleaned of small chips. It can not only clog the technological holes in the oil pump and other places, but also prevent the brake from working.

Operating Instructions for Partnerа 350

In this manual you will find Not only a detailed description of the saw, but also the basic techniques of working with the tool. We would like to draw your attention that this chainsaw can operate on AI95 or AI92 gasoline with the addition of oil for two-stroke engines in a ratio of 1:50.

Chainsaw Partner 350 S. Features, troubleshooting, operating instructions

One of the most popular household chainsaws is the 350th model from Partner. This can be explained by a number of advantages of this model.

The most important qualities of such dust, which characterize them on the positive side:

  • Compactness and light weight with sufficient power;
  • Relatively democratic price;
  • Durability;
  • Excellent repair facilities.

Chainsaws Partner. Features:

Many sources claim that it was this Swedish company that produced the first serial household chainsaws in Europe. And it happened in 1949.

It is generally accepted in our country that these are good Chinese saws, and this is partly true. Most of the Partner chainsaws sold in our market are assembled in China, which is honestly written on their nameplates. But besides China, the saws of this brand are also produced in America, Italy, Norway and England, and you can also purchase them.

For over 10 years this brand has been owned by the Husqvarna concern. One of the leading manufacturers in this segment, which affects not only the design features of the saw, but also the widest network of service centers that can quickly and efficiently service it.

Few people know, but for the first time the chainsaw chain brake and the handle heating system were applied precisely on Partner chainsaws, so they should not be underestimated.

There are about 30 modifications of this brand’s chainsaws. Here is the smallest Partner 340S saw on the market today, with 1.44 kW at 13,500 rpm, to the most powerful Partner 842 with 1.6 kW at 12,000 rpm.

But, perhaps, the 350th model remains the most bought.

Saw Partner 350 overview

We will consider it in more detail.


  • Power 1.52 kW;
  • Working volume 36 cm3;
  • Idling speed 3000 rpm / min;
  • The maximum recommended speed is 13000 rpm. / min;
  • Saw bar length 40 cm;
  • Chain pitch 3/8 “.

The use of saw bars with a length of 45 cm is allowed, but for this length the saw is still rather weak.

The saw is equipped with a hand chain brake, an easy start system, a primer for pumping fuel, a carburetor air damper regulator, chrome-plated cylinder walls and a cyclotron air preparation system. It is assembled quite qualitatively and, yielding in class to more eminent classmates from Husqvarna and Stihl, surpasses in its consumer characteristics almost all other chainsaws of the household segment.

Disadvantages of the saw

In the Russian market, you can find not very high-quality fakes of the Partner 350 chainsaw, which is not only an additional evidence of its popularity, but also harms the brand as a whole. And other models of this brand are also popular among summer residents and farmers.

If you are ready to consider Partner 350 as your home tool for sawing thin trees, pruning branches and other not very bulky work, then you should also know the disadvantages, most often called by their owners:

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1. Not a very high-quality vibration damping system, as a result of which the hands get tired quite quickly. But, taking into account the fact that this is a household tool that requires 15.20 minutes of rest every 20.25 minutes of work, you can put up with this drawback.

2. Oil leakage from the chain lubrication system, which, however, suffers from most chainsaws equipped with it, including the more eminent relative of Partner chainsaws. Husqvarna. (Link)

3. Lack of visual control of the oil level, which is not very convenient in operation, and operating the saw without lubrication will lead to rapid stretching, overheating and wear of the chain.

Of course, you can use this saw to cut wood up to 30.35 centimeters thick, but its main purpose. Work on the site. Therefore, in conclusion, we offer you the most objective review of this model:

Dear readers, if you have any questions, ask them using the form below. We will be glad to communicate with you;)

DIY Partner 350 carburetor tuning

Before starting adjustment work, it is necessary to clean the main fuel unit from dust and dirt. To do this, you can use a compressor with compressed air or a carpenter’s broom brush.

To adjust the carburetor, holes are provided on the left side of the power unit, however, for the convenience of determining their position, experts recommend dismantling the protective plastic casing. First, turn the screws for the quantity and quality of fuel all the way clockwise, then loosened them by 1/5. ¼ turnover.

Chainsaw carburetor Partner 350 with adjustment screws

When the cover is removed, you need to know that the screw for the quality of the fuel mixture is in the case and, accordingly, the screw for adjusting the amount of gasoline is located on the left. For convenience, the carburetor body is marked under the bolts:

It must be remembered that the carburetor of the Partner 350 chainsaw must be adjusted while the engine is warmed up. At high temperatures, the metal expands linearly, as a result of which the throughput of the channels increases.

As soon as the cylinder becomes warm, screw “L” is tightened until the GIS gives the maximum crankshaft speed. Then we twist it a quarter of a turn. It should be noted that in this position, the screw for the amount of mixture supply must maintain the engine at idle. If such a setting is not enough, then boldly unscrew the bolt “T” in the stable operation of the engine. Using the screw “H” I correct the work of the Partner chainsaw at maximum speed.

Checking the spark on the spark plug electrode

To diagnose the presence of a spark, it is necessary to remove the spark plug and DO NOT take out the high-voltage cable, make a few jerks with the starter. If there is a discharge, you will need to set the gap between the central and side electrodes. Its value in Partner 350 should not protrude beyond 0.7 to 1.2 mm.

Adjusting the spark plug gap with a feeler gauge

Failure to reach this distance can lead to incomplete combustion of the fuel mixture and, as a result, increased fuel consumption with limited power of the unit. As a result of exceeding this parameter, there is an inconsistency in the occurrence of a spark and interruptions in the operation of the internal combustion engine.

If there is no spark on the electrode, it is necessary to replace the candle and repeat the diagnostic manipulations described above.

Diagnostics and adjustment of ignition Partner 350

The absence of a bright blue spark in the plug may indicate the need to inspect the ignition module and adjust the gap. For THESE purposes, remove the plastic protective cover from the saw and check the condition of the reel. The wires leading to it Must be firmly fixed with screws. They must NOT dangle at the connection point. Moisture must not be present on the flywheel of the drive shaft, as it interferes with the generation of an electromagnetic field.

Flywheel and ignition module for Partner 350 chainsaw

In the absence of such inconsistencies, you must make sure that the clearance between the module and the flywheel is correct. Its value should not be painful and not less than 0.2 mm, and later, if it does not coincide with the recommended distance, you need to independently adjust the ignition of the Partner 350 chainsaw.

After checking the ignition, proceed to the diagnosis of the fuel supply system.

Crankshaft bearing diagnostics

An important factor in the correct operation of the engine is played by bearings and oil seals of the crankshaft.

Partner 350 crankshaft with bearing

To diagnose their wear, it is necessary to stagger the flywheel installed on the shaft in the vertical and horizontal plane. If there is a clear play, the rolling bearings must be replaced. If there are oily traces on the crankcase, then the oil seals will also need to be replaced. It is not superfluous to check the play of the Partner 350 crankshaft, for which we remove the cylinder and piston. With the help of his hands, his salary to the left and right, thereby imitating the natural movement.

Chainsaw troubleshooting

Experienced fellers know that a competent and accurate determination of the nature of a breakdown. This is half of the renovation work done. Based on many years of experience in repairing the Partner 350 chainsaw, specialists have developed a special method for diagnosing problems.

The main breakdowns of the Partner 350 chainsaw

This allows you to significantly save time and avoid unnecessary operations. Troubleshooting is recommended in the following order:

  • Chainsaw spark check;
  • Ignition coil;
  • Diagnostics of the fuel supply system;
  • Inspection of the crankshaft bearings.

Chainsaw Partner 350 Frequent breakdowns, carburetor adjustment

Among the huge selection of models on the modern construction market, the Partner 350 chainsaw stands out, which is produced by a subsidiary of Husqvarna.

General view of the Partner 350 chainsaw

Simple and easy to use, reliable and unpretentious, this saw has gained wide popularity among summer residents and owners of country houses. Sawing firewood, pruning trees and branches. This is not the whole list of works that this model can handle without problems. Despite the well-thought-out design and layout of the units, over time the power unit, transmission elements and fuel system wear out.

Final check at idle speed

Before this procedure, it is necessary to make a full adjustment of the components of the carburetor when operating at maximum speed. Next, you should check the operation of the device in idle cold mode. When the correct parameters are achieved during the adjustment, you will notice that the carburetor design exactly matches the following criteria:

  • When connecting the idle cold mode, the chain does NOT move.
  • When the accelerator is pressed even slightly, the engine revs up at an accelerated pace. With a gradual deepening of the pressure, it can be seen that the engine speed rises commensurately, the maximum permissible values ​​mature.
  • When the engine is running, you can compare its sound to a four-stroke device.
  • If violations are noticed in the above parameters or the device was not completely adjusted, you need to perform the main setup step again. Sometimes actions are performed incorrectly. In this case, the device may fail due to the loss of the correct node settings. In this case, you will have to contact a specialist.

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    Dismantling the carburetor when it is necessary to check or repair components

    The device of different models of carburetors is almost the same, so when working with them, you can use the standard scheme. All elements must be removed carefully, and then laid out in the order below, so that you can successfully place the items in place at the end of the repair work.

    • The top cover is removed. To do this, Unscrew the 3 bolts holding it in a circle.
    • The foam is also removable, as it is the upper part of the air-conducting filter.
    • The fuel hose is removed.
    • The drive thrust is output directly to it.
    • The cable end is detached.
    • The petrol hose can be completely removed by systematically pulling it off the fitting.

    To finally prepare the carburetor for overhaul or replacement of the smallest parts, you need to carefully disconnect it from the main system. Sometimes further disassembly is required. Unscrew the components carefully and fold the fasteners in groups, as these small parts are easily lost.

    First stage

    The adjusting screws for the highest and lowest speed should be moved clockwise until the highest resistance is encountered. When the screws reach the stop, you need to move them in the opposite direction and leave them after 1.5 turns.

    Checking acceleration work

    A little research needs to be done. Device acceleration is initiated. The serviceability of the engine should be assessed during the maximum revolutions. When the engine is functioning correctly, then when you press the accelerator, the speed rises quickly to 15,000 rpm.

    About the carburetor device

    The carburetor serves to mix the combustible mixture with air in compliance with predetermined proportions. If the exact dosages are NOT followed, the correct operation of the engine is jeopardized. When a large amount of air enters during the mixing of the components, and there is not enough fuel, then such a mixture is considered “poor”.

    Over-saturation must not be allowed, since with a large amount of fuel in comparison with air, malfunctions or engine wear are also possible. Carburetor adjustment is necessary Not only before the initial introduction, but also when any deviations in its operation are detected. Before starting work with the chainsaw, do not forget to run it in.

    The carburetor design contains a standard set of elements, but it may vary slightly depending on the manufacturer. Components:

    • The basis. It is a special tube that visually resembles an aerodynamic structure. Air passes through it. In the transverse direction, a damper is located in the middle of the pipe. Its position can be changed. The more it is Pushed into the passage, the less air enters the engine.
    • Diffuser. This is the tapered part of the tube. With its help, the air flow rate increases exactly in the segment from which the fuel comes out.
    • Fuel supply channels. The fuel mixture is contained in the float chamber, then passes into the nozzle, from which it flows into the sprayer.
    • Float chamber. It is a separate structural element, reminiscent of the shape of a tank. Designed to constantly maintain an optimal level of fuel fluid in front of the entrance to the channel where the air comes from.

    Looking for models that are cheaper, but reliable and time-tested? Pay attention to Russian-made chainsaws.

    Or Explore foreign chainsaw manufacturers such as Stihl.

    What you need to have to set up and adjust a chainsaw with your own hands

    Every carburetor owner must have the right tools to adjust this system. There are three adjusting screws, which are located on the body of the device. They have their own markings:

    • L. Screw for low speed correction.
    • H. High speed adjustment screw.
    • T. Carries out regulation of idling, in most cases it is used for experiments.

    Before adjusting the carburetor, you need to prepare the device:

    • The engine warms up, that is, it starts about 10 minutes before the repair, and turns off when you start work (see How to start a chainsaw).
    • The air filter is checked and washed.
    • The chain is stopped by turning the screw T as far as it will go (see Chain oil).

    To carry out a safe repair, you need to prepare a flat surface where you can carefully position the device, and unscrew the chain in the opposite direction. We need a tachometer. It determines the presence of a malfunction in the carburetor. When the screws are turning, the sound should be Perfect and absolutely even. If squealing notes are noticed, then the mixture is oversaturated.

    Maximum RPM

    Turn screw H clockwise until the maximum speed is reached.

    The Partner 351 saw, according to the instruction manual, has a rotation speed limit of 13,000 rpm. Exceeding this indicator is unsafe for the engine and is manifested by characteristic interruptions in ignition and “singing” of the internal combustion engine, which can be corrected by gradually unscrewing the adjusting screw in the opposite direction.

    Carburetor device

    Purpose of the carburetor of the Partner 351 chainsaw. Preparation and supply of the correct fuel-air mixture to the engine.

    The carburetor power supply system of the chainsaw engine is arranged according to a typical scheme and includes a fuel pump, a main mixing chamber with a membrane, a throttle and an air valve, and three adjusting screws (needles). Technological channels for the movement of the fuel-air mixture are provided in the aluminum body.

    Throttle valve. A brass plate that controls the amount and speed of air entering through the variable air inlet. Constriction towards the center and expansion towards the opposite edge, as in a Venturi tube, creates a vacuum that traps fuel on its way to the engine.

    The pressure in the main chamber of the carburetor is close to atmospheric, but when the engine is started, a vacuum occurs in the air passages. Opening the damper increases the intensity of the air supply, and with this the power of suction of fuel, and the number of working revolutions of the internal combustion engine.

    The Partner 351 chainsaw has a serious flaw in the power system, which leads to interruptions in work. This drawback lies in the adapter installed between the engine and the carburetor (we already talked about this above, where the location of the adapter was marked in the photo).

    Over time, a backlash appears at the junction and the chainsaw begins to suck in air. This malfunction manifests itself as a failure at startup (the saw simply does not start), or during operation in the form of instability of revolutions, they spontaneously rise and then fall.

    The author tells in detail what caused this problem on the Partner 351 chainsaw and how to fix it yourself.


    • Smoothly turning the screw L in one direction and the other, find the position in which the revolutions are maximum.
    • Unscrew screw L a quarter circle counterclockwise.
    • When the chain is rotating at idle speed, unscrew the screw T to the left until it stops.
    • If, after tuning, the engine does not start well or stalls quickly, it is necessary to Unscrew the screw L another half turn and adjust the screw T again.
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    Repair of the carburetor of the Partner 351 chainsaw (main malfunctions, their elimination)

    Even a very careful and correct adjustment of the carburetor may NOT solve some of its malfunctions and the problems caused by them in the operation of the Partner 351 chain saw.

    In some cases, interruptions in the operation of the carburetor are associated with clogged jets, fuel and air filters and, as a result, “underfilling” of fuel. The main symptoms of this problem are loss of power and unstable engine operation. Dust, small debris and even water droplets can become the reason, and water frozen in the carburetor completely blocks the fuel supply channels.

    In the presence of a compressor, all channels of the carburetor are purged with compressed air, and if the procedure did not help. They wash it in an ultrasonic bath (jewelry or for washing optics) with the introduction of special carburetor water. During the cleaning process, it is prohibited to use metal needles, wire, fluffy or “loose” fabric.

    There are often cases when the chainsaw begins to work unstably due to a leakage, which is formed due to the bursting spacers between the carburetor and the chainsaw engine (pictured below). The only way to solve the problem. Replacement for a serviceable one.

    Adapter between engine and carburetor for Partner 351 chainsaw

    What carburetor is used on the Partner 351 chainsaw

    The original Swedish chainsaw of the Chinese assembly Partner 351 is equipped with a Japanese two-stroke carburetor with a built-in Walbro WT391 membrane-type fuel pump. If the internal combustion engine power supply unit is replaced with a Chinese analogue, it means that the chainsaw has been repaired.

    Chainsaw carburetor device

    Not a single repair event is complete without knowledge of the basics of the mechanism. By understanding the constituent elements and the principle of operation, it is easier to determine the cause of the breakdown.

    Any malfunction in the carburetor threatens to stop the engine

    Carburetor. One of the main functional parts of the engine, which serves to prepare and supply a fuel mixture consisting of certain proportions of fuel and air. As soon as the proportions are violated. The engine starts to “junk”, or even stops working.

    You can achieve the correct operation of the carburetor by examining its “stuffing”:

    • Cross flap tube for air flow regulation.
    • Diffuser. Restriction for increasing air flow, located near the fuel inlet.
    • The atomizer from which fuel comes (fuel needle in the diagram).
    • Float chamber that regulates the fuel level at the entrance to the channel.

    This is how it looks in the diagram:

    In the display diagram, the interaction of fuel and air flow

    How it works: A jet of air in the diffuser atomizes the fuel, creating a mixture that flows into the cylinder. The more fuel is supplied, the higher the engine speed. Different carburettors work in the same way.

    Chainsaw carburetor adjustment: we analyze all the technical nuances of the work

    Summer cottage construction and repairs are not complete without the use of a chainsaw, as well as garden maintenance. Due to a malfunction of the tool, all work can get up, so it is so important to be able to disassemble it yourself, find problems and fix them. With enough experience and dexterity, it is even possible to adjust the carburetor of a chainsaw. The procedure is complicated, or rather, jewelry. How to carry out the adjustment procedures, we suggest you disassemble today.

    When is adjustment necessary at all?

    It is the adjustment of the carburetor of the chainsaw that is required in rare cases, more often there are problems associated with fuel inflow or wear of parts. But sometimes “symptoms” indicate that it is necessary to precisely adjust the mechanism. Here are some signs:

    • After the engine starts, it immediately stalls. As an option. Doesn’t start at all. The reason lies in the excess of air and fuel shortages.
    • The increase in fuel consumption, and as a result. Large amount of exhaust gases. This is due to the reverse process. Fuel mixture oversaturation.

    The reasons for the adjustment failure can be mechanical:

    • Due to strong vibration, the protective cap is damaged, as a result of which all three bolts lose their established fixation.
    • Due to wear on the piston part of the engine. In this case, adjusting the carburetor of the chainsaw will only help out for a while, it is better to replace the worn part.
    • Due to clogging, which occurs due to low-quality fuel, scale or damage to the filter. The carburetor requires complete disassembly, flushing and adjustment.

    If the chainsaw suddenly stops working, you need to disassemble it to find out the reasons

    Step by step instructions for disassembly

    The carburetor device of models of different brands is almost the same, so take the Partner chainsaw as an example. We carefully remove each element and put it in order, so that later it would be easier to assemble.

    Chainsaw carburetors from different manufacturers, if they differ, then not fundamentally

    The top cover is removed by loosening three screws. Following her. Foam rubber, part of the air filter.

    The arrows indicate the bolts, which must be unscrewed to remove the cover

    Then we remove the fuel hose, behind it. Drive rod.

    The upper arrow points to the fuel hose, the lower one. For traction drive

    Next, remove the tip of the cable.

    The arrow shows the end of the cable, which must be removed

    On the left from the fitting we pull off the gasoline hose.

    We also carefully remove the gasoline hose indicated by the arrow

    By finally disconnecting the carburetor, it is ready for adjustment. Its mechanism is rather complicated, therefore, if further disassembly of the carburetor is required, the elements should be removed very carefully. They are small so they can get lost.

    The carburetor consists of many small parts, which should be laid out in order when disassembling

    Features of setting and adjustment

    To find out how to adjust the carburetor on a chainsaw, you should learn to distinguish between three screws (some models have only one).

    The L and H screws are similar only in appearance, in fact they are different

    Each screw has its own letter designation:

    • “L” is for setting low rpm;
    • “H” is needed to adjust the upper speed;
    • “T” is needed to adjust the idle (for models with one screw, only it is present).

    The factory setting is optimal, and with the help of the screws they adjust the engine operation in special situations (work associated with different climatic conditions).

    The diagram shows the outputs of the carburetor adjustment screws with the lid closed

    A special tool is used to adjust the chainsaw.

    Adjustment is carried out only with screws L and H. To increase the speed, turn them clockwise. To reduce. Counterclock-wise. Sequence of using screws: L. N. T.

    If you have doubts about the adjustment, it is better to contact a specialist, since an incorrect setting can damage the engine.