Tuning The Carburetor Of The Partner 351 Chainsaw

Chainsaw Partner 351
Chainsaw Partner 351 Chainsaw Partner 351 belongs to the range of Chrome models, which have a chrome-plated cylinder. Thanks to this, work

User’s manual

Before starting work with the Partnera 351 chainsaw, you must read the instructions. It indicates the features of the operation of equipment, the nuances of its assembly and maintenance, the rules for adjusting the carburetor of a chainsaw, describes the most frequent breakdowns and ways to eliminate them, and also presents the brands of fuel and oil that are suitable for this model.

You can read and download the instruction manual for the Partner 351 chainsaw at the following link:

Carburetor setting

The chain saw comes with a carburetor already set at the factory, but after a while you notice that the saw does not function as well. In order not to carry the tool to the service center, you can try adjusting the carburetor of the Partner 351 chainsaw with your own hands. This procedure may be required only in two cases:

  1. The chain is idling;
  2. Saw does not idle.

Read the instruction manual for carburetor adjustments and user reviews for this procedure.


Manufacturer Partner
Manufacturing (assembly) China
Homeland of the brand Sweden
Saw class Household
Power, h.P. (kw) 1.8 (1.3)
Engine volume, cm3 36
Chain pitch, inches 3/8
Chain thickness, mm 1.3
Number of chain links 56
Fuel tank volume, l 0,4
Oil tank volume, l 0.2
Tire length, cm (inches) 40 (16)
Noise level, dB (A) 106
Warranty, years 1
Weight, kg 4.7

Carburetor device

The purpose of the Partner 351 chainsaw carburetor is to prepare and supply 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). The aluminum body provides technological channels for the movement of the air-fuel mixture.

The throttle body is a brass plate that controls the amount and speed of air entering through the variable air intake. Tapering towards the center and widening towards the opposite edge, as in a venturi, creates a vacuum that traps fuel on its way to the engine.

tuning the carburetor of the Partner 351 chainsaw

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 it the power of suction of fuel, and the number of working revolutions of the internal combustion engine.

Advantages and disadvantages

The main task of the engines of motorcycle tools, in particular, chainsaws, is stable and confident operation in any position with respect to gravity. This feature, provided by a diaphragm carburetor with a built-in pump, along with its structural simplicity, is a significant advantage of the Partner 351 internal combustion engine supply unit.

The disadvantages of the carburetor include the relative complexity of the adjustment, the narrow range of the amount of the mixture at the outlet, and slow transitions between steady-state modes. In addition, it is sensitive to accelerations perpendicular to the membranes.

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 chainsaw. If the adjustment fails to restore the normal performance of the internal combustion engine power unit, it must be dismantled, disassembled and repaired.

In some cases, interruptions in the operation of the carburetor are associated with clogged nozzles, 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. The reason may be trapped dust, small debris and even water droplets, and the 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 are suitable) using a special carburetor fluid. During the cleaning process, it is prohibited to use metal needles, wire, fluffy or "loose" cloth.

There are often cases when the chainsaw begins to work unstably due to a leakage, which is formed due to a bursting spacer between the carburetor and the chainsaw engine (pictured below). The only way to solve the problem is to replace it with a good one.

Adapter between engine and carburetor of Partner 351 chainsaw

Chainsaw starting instructions

The Partner 351 chainsaw works on the same principles and has a similar structure as other tools with gas engines:

  1. Before the first use, all the components of the Partner 351 chainsaw are securely screwed on, the integrity of the body is checked.
  2. The chain tension is checked before each start. If necessary, the chain is tensioned or relaxed using the adjusting screw.
  3. The amount of oil is checked before each start.
  4. The chainsaw can only be started from a hard surface. The foot should firmly press the tool to the ground.
  5. Before starting the damper is placed in the "open" position.
  6. The start button is moved to the "on" position after which you need to press the primer 5 times and start pulling the starter cord. The main thing is to start the chainsaw smoothly, without jerking.
  7. After starting, the engine should idle for 60 seconds. Then you can start working by adjusting the power with the throttle.

In the segment of non-professional chainsaws, Partner 351 (Partner 351) takes its rightful place. Lightweight, powerful and reliable, the saw allows you to perform a wide range of sawing tasks at the household level.

The chainsaw is ideal for working in a summer cottage. It copes well with small fruit and berry trees, pruning. It can be used to work in the forest with small diameter trunks. Partner 351 is suitable for construction work.


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

  • Motor power 1400 W (1.9 hp);
  • Tire 35 cm. It is possible to install a tire at 41 cm;
  • 56-link chain with 3/8 ” pitch;
  • Spark plug – Bosch WSR 6F;
  • Fuel tank capacity 380 g;
  • 200 gr oil tank;
  • The noise level is just over 100 dB.

The CCS air filter significantly reduces fuel consumption. The double air purification system increases the engine resource of the Partner 351 chainsaw. The chain runs at high speeds.

Sophisticated ergonomics and a reliable vibration damping system allows you to use the tool for several hours without interruption.

The chain brake engages instantly, making your chainsaw even more comfortable and safe.

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

The carburetor is 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 altogether.

You can achieve the correct operation of the carburetor by examining its "filling":

  • Cross-flap tube for air flow regulation.
  • Diffuser – Constriction to increase the air flow rate, located near the fuel inlet.
  • The nozzle from which fuel comes (fuel needle in the diagram).
  • A float chamber that regulates the fuel level at the entrance to the channel.

This is how it looks in the diagram:

The diagram shows the interaction of fuel and air flow

How it works: A jet of air in the diffuser atomizes the fuel, creating a mixture that enters 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 sufficient experience and dexterity, it is even possible to adjust the carburetor of a chainsaw – a complicated procedure, or rather, jewelry. How to carry out the adjustment procedures, we suggest you disassemble today.

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 to make it easier to assemble later.

Chainsaw carburetors from different manufacturers, if they differ, it does not matter

The top cover is removed by unscrewing three screws. Following it is foam rubber, an integral part of the air filter.

The arrows indicate the bolts that must be unscrewed to remove the cover

Then we remove the fuel hose, followed by the drive rod.

The upper arrow points to the fuel hose, the lower arrow to the drive rod

Next, remove the tip of the cable.

The arrow shows the end of the cable to be removed.

On the left from the fitting, we pull together the gasoline hose.

We also carefully remove the gasoline hose indicated by the arrow

We finally disconnect 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 be lost.

The carburetor consists of many small parts, which should be laid out in order during disassembly.