How a carburetor works
Proper adjustment is possible only if the device of a chainsaw carburetor was studied in advance and the quality of this part was checked. For instance, Walbro is a manufacturer of carburetor for Partner p350s. An indication of quality in this case is the marking WT-891.
Knowing this information is essential for ordering replacement parts.
The carburetor on a Partner 371 chain saw and other models has a classic design. The main elements are:
- fuel pump;
- main chamber with a diaphragm;
- throttle valve and air valve;
- screws (quality, quantity and idle speed adjustment).
In addition to these parts, the carburetor has technological channels, through which the mixture of gasoline and oil moves.
The principle of operation is as follows. An impulse is fed from the crankcase to the fuel pump. This is where the carburettor starts. After receiving an impulse, the fuel mixture is directed to the main chamber, entering there through the needle valve, which is controlled by the diaphragm. From the main chamber through technological channels, the fluid is routed into the cylinder, and the amount of fluid can be independently adjusted using the throttle.
In addition, it is possible to adjust the flow capacity of the technological channels. For this purpose you have to use the quantity and quality screws, which work like a slide valve.
Algorithm and description of the disassembly process
If your Partner 350 chain saw needs to be completely disassembled, the first place to start is with the compressor to clean the saw. Next, the chainsaw assemblies are removed in the following order:
After the first disassembly step is complete, clean the chainsaw again with a compressor, t. к. already have access to the air ducts, which in most cases are heavily contaminated with wood dust.
In the next step it is convenient to remove the air filter housing and the carburetor of the Partner 350.
After removing the carburetor, the cylinder intake window must be plugged with a rag, this will protect against the ingress of foreign objects into the engine crankcase.
The muffler can be removed after the carburettor is removed or after the engine is removed. The exhaust window, too, is closed with a rag.
This requires the use of a piston stopper by inserting it into the spark plug hole.
The clutch on all Partner 350 chain saws is unscrewed in the direction of the chain, this is done to prevent it from unscrewing during operation. Flywheel nut has a standard thread and unscrewed with a 13 head, counterclockwise.
After removing the clutch is access to the oil pump, it must also be removed.
The last step is to loosen the screws on the engine and remove it from the housing.
Instructions for removing the flywheel from the crankshaft
To remove the flywheel you will need to use a special puller, but most craftsmen use a mallet made of soft metal, t. к. With its help the process of removal is greatly accelerated.
The bottom line is that the flywheel nut is unscrewed until it is level with the plane of the shaft, then with a hammer and a mallet, set on the nut, with one sharp blow the flywheel is removed from the shaft.
The method is a little barbaric, but time-tested and recommended by many masters as the most practical and reliable.
The structure of a Chinese chainsaw carburetor. How a chainsaw carburetor works
For independent adjustment of a chainsaw carburetor it is not necessary to be a professional motor-technician. However you should learn some aspects of carburetor operation, concerning the process of fuel mixture preparation.
The vast majority of chainsaws are equipped with Chinese-made Walbro carburetors. In their structure they are simple, if not to say primitive. There is a one-piece body with a through hole. Inside the hole there is a diffuser. a narrowing of the passage with a fuel injection channel. There are two sides of the flaps: the smaller one is a throttle valve, it regulates the amount of fuel mixture to be fed into the cylinder. The larger flap. the air flap, serves to limit air flow during a cold start.
Walbro carburetor design: 1. fuel inlet fitting; 2. diaphragm pump pulse channel; 3. inlet valve; 4. fuel pump diaphragm; 5. outlet valve; 6. filter screen; 7. air damper; 8. throttle valve; 9. fuel channel; 10. idle stroke adjusting screw; 11. needle; 12. idle stroke nozzles; 13. control membrane; 14. fuel chamber; 15. main nozzle; 16. diffuser; 17. main adjusting screw
All magic of fuel preparation takes place in hidden channels and diaphragm pump chamber. When you turn the throttle valve, the cross-section of the channel through which fuel is injected into the mixing chamber slightly increases and the fuel comes in a larger volume. The carburetor has two kinds of valves: one for low and one for high. When changing the position of the throttle valve, the fuel flow changes proportionally between the two valves.
The need for such a device is that the quality of the mixture at idle and under load should be different. In this case, the channel through which the fuel is fed to the mixer at idle speed is not completely blocked when the engine accelerates and vice versa. the channel of maximum rpm is a little bit pitted at idle speed.
The following types of malfunctions are common to your Partner chainsaw:
- Engine malfunctions, such as problems with the ignition, fuel supply, or exhaust and piston-cylinder systems;
- carburetor component failure, such as the clutch assembly, chain brake, or lubrication system.
The causes of failure can vary, but more often than not it is improper use, not enough oil, or a poor-quality fuel mixture.
Ремонт Бензопилы PARTNER 350/ Chainsaw Repair
How to remove and disassemble
You can correct problems with your chainsaw carburetor only after you have removed the part. And to do this, you need to disassemble the chainsaw itself. This work will have to be done in the following sequence:
- Remove all assemblies in strict order. First you need to remove the chain brake cover and the saw headset, then the top cover, the saw handle and the starter.
- After these parts are removed, you need to clean the saw with a compressor with a nozzle.
- After that you need to close the intake window, as there is a risk of dirt and foreign objects getting inside.
You can clean the carburetor in different ways, most often do it with air. The sequence of work is as follows:
- Unscrew the upper bolt of the part cover.
- Remove the valve gasket. After that you need to blow through the wire mesh with compressed air. Do not blow very close to it, but at some distance from it.
- No other parts of the carburetor should be removed. You can use a special liquid to clean the surface.
- Now the carburetor needs to be assembled, attaching the parts in reverse order.
Other repair work may be necessary for your Partner chain saw to operate efficiently. Performing the repair with your own hands is not difficult.
The most common problem is a lack of adjustment:
- spark in the spark plug (you must either clean the gap on the spark plug or replace the coil or flywheel with similar parts);
- fuel supply (the cause may be a clogged hose or fuel filter);
- Before you start, mount the barbed blade and secure it with two screws;. Air filter has to be flushed.
Setting the carburetor chain saw Husqvarna 137. Instructions for tuning
Before proceeding to the adjustment of the chain saw “Husqvarna 137”, it is necessary to carry out its installation. Before you start, you need to study the device of the chainsaw Husqvarna 137.
- Be sure to wear gloves to protect. They are not included in the delivery set, so their purchase should be taken care of in advance. First you must install the saw’s comb and fasten it with two screws.
- If no chains and tires are installed, they must also be put in place. To do this you must remove the cover and the nuts securing it. If there is a conveyor spacer on the chain, it must be removed.
- Adjust the tension of the chain with the adjusting screw. It is important that the grip must engage in the hole in the tire. Turn the adjusting screw counterclockwise to advance the gripper. This is the way to get the catch in the correct position.
- Next you need to prepare the chain for installation. To do this, choose the correct position. The sprocket, which is located behind the clutch drum, is placed on the chain. The chain is running between the teeth of the sprocket.
- Move the top of the guide bar into the groove on the bar that surrounds it.
- Then the adjusting nuts are inserted and tightened manually. Once the chain is fully adjusted, it can be tightened finally.
- To find out how to adjust the carburetor, consult the manual in the appendix to this model. Tuning the Husqvarna 137 carburetor is usually no problem.
Step-by-step instructions for adjusting the carburetor on your Partner chain saw
One of the circumstances of incorrect operation of the engine chain saw Partner 350, it is improper adjustment of the supply of fuel consistency in the combustion chamber. This article shows how to adjust the carburetor on your Partner 350 without calling the service center.
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 set the bar to 41 cm;
- 56-link chain with 3/8-inch pitch;
- The spark plug is a Bosch WSR 6F;
- fuel tank capacity 380 gr;
- oil tank of 200 gr;
- The noise level is just over 100dB.
CCS-operated air filter helps significantly reduce fuel consumption. The dual air-purifying system extends the life of the Partner 351 chainsaw motor. The chain is running at high rpm.
Intelligent ergonomics and reliable vibration damping system allow hours of uninterrupted use.
The chain brake engages immediately, which makes working with a chainsaw even more comfortable and safe.
Owners of the “Partner-350″ gasoline saw have to adjust the ignition quite often. When starting up the machine for the first time, it is important to check the idle speed. To do this, turn clockwise the screw that is responsible for adjusting the idle speed. Once it has caught on, it can be turned around by four and a half turns in the opposite direction. If the engine operates with no chain rotation after these operations, it can be concluded that there is no problem. Otherwise, it is necessary to seek help from a service center, because using a chainsaw in this condition can be dangerous.
Adjusting the carburetor on a Partner 340s chain saw. Pull the carburetor on your Partner 350 chain saw with your own hands
Properly adjusting the carburetor on your Partner 350 chain saw helps prevent the above-mentioned problems from happening. This work begins with a disassembly. Adjusting the carburetor on a Partner 350 chain saw requires knowledge of the construction of the working unit.
When disassembling the elements to repair the carburetor of the Partner saw, it is useful to use the following recommendations:
- When you remove the elements of your Husqvarna saw with your own hands, you need to be as careful as possible. Every part needs to be removed. It is advisable to arrange the parts in the sequence in which they are removed. This will help make the subsequent assembly process as quick as possible. Dismantling can be done quickly.
- The upper cover is held in place with three bolts. You will need to carefully disassemble them. Under the removed cover there is a foam layer. It serves as an air filter option.
- You will need to remove the filter rod in the saw. To do this, you must remove the gasoline hose.
- To make the adjustment of the carburetor of the chainsaw Partner 350 requires the removal of the tip, which is on the cable. To do this, carefully remove the fuel hose and disconnect the carburetor. Take it off slowly.
- After performing the above steps you can start adjusting the carburetor on your Partner 350 chain saw. Pay attention to the fact that this type of operation is considered quite labor-intensive. It is necessary to perform the adjustment step by step. The individual elements have small dimensions. It is important not to lose them when disassembling, adjust.