How to increase the oil flow on your chainsaw

Chainsaw carburetor adjustment, disassembly, search for typical faults

Most modern chainsaws have very similar carburettors with a few exceptions.

Often the difference lies in the quality of the parts and the presence or absence of a primer connection tube. a manual pre-priming pump.

Therefore, we will consider them almost impersonal, without going into the nuances.

The device and principle of operation of the chainsaw carburetor

The task of the carburetor is to prepare a mixture of gasoline and oxygen and feed it into the cylinder in doses. Mixing takes place in the diffuser (16). the converging part of the carburetor, where the air flow is accelerated. Gasoline of various fractions (coarser and finer) and purified air after the air filter enter the diffuser through 2 nozzles (15) and (12). Its amount is regulated by the air damper (7) at the diffuser inlet. The amount of the finished mixture supplied to the cylinder is regulated by another flap (8), which is behind it.

Two screws (17) and (10) (L and H) regulate the amount of gasoline passing through the jets. The amount of gasoline in the float chamber (14) is regulated by a needle valve (11), the operation of which is monitored by a membrane (13). The second diaphragm (4) doses the amount of fuel supplied to the chamber depending on the engine speed. On the way, it is filtered through a filter (6).

If both filters, air and gasoline, are clean, the channels and nozzles are not clogged, the membranes are intact, and the needle valve reliably regulates the amount of gasoline in the float chamber, then the carburetor is working properly, and for normal preparation of the mixture it is necessary to correctly adjust the amount of gasoline supplied through the nozzles. We will not talk about mechanical wear of metal parts of the body and valve rods of the carburetor, because it will be cheaper to simply replace it than to repair it.

How to adjust the carburetor on a chainsaw?

All saws from the factory come with an adjusted carburetor.

And, since it is protected by a plastic case, it does not need additional adjustments for a long time. And you should intervene in its work only when the saw, with a guaranteed serviceable cylinder-piston group, begins to stall, which is most often caused by a lack of fuel and, as a consequence, an excess of air.

The second symptom of poor carburetor performance is excessive fuel consumption and increased smoky exhaust, indicating an excess of gasoline in the mixture. In this case, clean (or replace) the air filter and make sure that the cause has not been eliminated before climbing to the carburetor.

Sometimes a violation of the carburetor adjustment occurs gradually, due to increased vibration of the tool, as a result of which the adjusting screws can turn from their original positions.

First of all, even before removing and disassembling the carburetor, you should try to adjust it. For this:

Carburetor adjustment should be started with screw L, which adjusts the fuel supply at low speeds. By rotating it, you should achieve the highest rpm. Turns increase when tightening this screw.

Next, use the H screw to adjust the quality of the mixture. If the saw smokes, this is a sign of a rich mixture, and if it squeals, it is a poor one. In the first case, screw H should be tightened, and in the second, vice versa. Be very careful with this screw; incorrect adjustment can even damage the saw. In no case should it be tightly twisted.

The adjustment is completed by setting the idle speed, which is set with screw T. At high speeds, the clutch cams are in the open position and the saw chain moves. The T screw adjusts the throttle adjuster stop from the outside and does not fit inside the carburetor. You should not keep the engine speed too low, while the load on the crank mechanism increases, but the chain must also stop at idle. This screw in some saws may have a different letter meaning.

Some carburetors initially have only one setting. idle, in which the quality of the mixture is set by the parameters of the jets and factory settings initially. The idle speed video on such carburetors is also suitable for all other types of similar devices:

A violation of the saw operation modes without screws for adjusting the speed and quality of the mixture may indicate that it needs to be repaired or at least cleaned.

It remains to add that the final adjustment should be made only on a heated saw that has worked for at least 10 minutes.

Self disassembly and repair of the carburetor

Let’s make a reservation right away: if you are not an expert in this type of activity, then it is better to contact the service center. Sometimes the cost of a carburetor can be as high as a third of the cost of the entire saw.

But, if you decide to disassemble the carburetor yourself, we recommend finding a couple of free hands, putting a video recorder in them and taking a close-up video of the carburetor disassembly in detail. This will help unambiguously when assembling it, because it is almost impossible to mark small parts for the correct order of its carrying out.

Almost 80% of carburetor failures can be blamed on the jet that supplies fuel to the diffuser. But, before cleaning it, we recommend stocking up on a repair kit, which necessarily includes membranes, gaskets, and sometimes this jet with a needle valve.

Even if disassembly reveals their integrity, it will be better to install new ones, because even a micronized change in the parameters of the membranes can affect the operation of the device.

If the jet has to be cleaned, then it is better to do this by first unscrewing it with a thin calibrated wire. It is better to blow the second jet with your mouth using a tube-guide or a bicycle pump, but in no case with a compressor. there is a high probability of damage.

We have compiled a video about the repair of a Stihl 180 saw carburetor, which has only an idle screw. But its internal structure is the same as that of almost all chainsaw carburetors:

And the point here is not only that the missing adjusting screws clutter up the picture, distracting from the essence of the process, but that this disassembled carburetor can also be slightly adjusted by adjusting the quality of the mixture. If your Stihl suffered from increased fuel consumption and smoked before the carburetor was repaired, then you can reduce the fuel supply by increasing the clearance of the needle valve by slightly bending its rocker arm. The reverse procedure can increase the fuel supply.

Always clean the filter when disassembling. To remove deposits, you can use the WD-40 preparation, but if you remember that this is actually white spirit with the addition of oil, then you can do with them. And the use of kerosene or acetone is also allowed.

The simplest, or preliminary, adjustment of the chainsaw carburetor can be done as shown in the video, and the final adjustment can be made after the saw has warmed up:

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

Troubleshooting

After it has been determined that oil is not being supplied, further diagnostics is possible only if the oil system is completely removed. Of course, changing the filter helps in some situations, but this is very rare.

Access to the oil pump of some saw models is possible only after complete disassembly, accordingly, without having the skills to repair gasoline tools, it is better to entrust the repair to professionals.

Chainsaw chain lubrication system

To supply oil for lubricating the chainsaw chain, a special pump is used in the tool, which is dosed, depending on the number of engine revolutions, supplies lubricant to the saw bar.

The system uses oil to lubricate the chainsaw chain, which has increased adhesion properties, this is necessary to evenly distribute the oil around the entire perimeter of the tire and keep it on it even at high chain speeds. Let’s take a closer look at the oil supply system implemented in modern chainsaws.

Chainsaw chain lubrication system

One of the important chainsaw systems, without which work is impossible, is the forced lubrication system of the chainsaw chain. It’s not a secret for anyone that at the time the saw is operating, the chain friction against the tire of the chainsaw, which causes it to heat up and premature wear. To soften friction, the chain mechanism must be constantly lubricated.

• Chainsaw chain lubrication system
• Lubrication system device
• Principle of operation
• Lubrication system malfunctions and how they are eliminated
• Signs of a malfunction of the lubrication system, checking its performance
• Troubleshooting
• Most common malfunctions
• Individual malfunction of the Stihl MS 180 lubrication system
• Conclusion

Lubrication system device

Depending on the brand of the chainsaw, the details of the lubrication system may differ slightly in design, but their total number and connection diagram remains unchanged.

The main components of the lubrication system are:

• oil tank located, as a rule, in the engine crankcase.
• Filter element, installed in the tank.
• The oil line is a small diameter oil-resistant rubber hose.
• The heart of the system is the oil pump.
• Worm gear gear transmission force from the engine to the pump.
• The tire of the chainsaw, it can also be considered an element of the lubrication system, since it has special holes for supplying oil, by the way, the chain itself is involved in the transportation of oil and, accordingly, also has some elements designed specifically to provide lubrication.

Most common malfunctions

• Broken oil hose. It can sometimes be detected by visual inspection. The problem is solved by replacing the defective part.
• Lack of threads on the oil pump shaft, replacing it will help.
• Defective thread on the pump drive gear is similarly solved by installing a new part.
• Absence of a corkscrew of the main shaft (relevant for some models of tools, for example, Homelite). You can fix it by installing instead of the native corkscrew, suitable for the diameter of the studs, cutting it to the required length.
• Blockage in the line. Can be removed by blowing with compressed air or mechanically using a wire of suitable diameter.
• Clogged filter element.
• The Stihl MS 180, which has a non-separable pump, often clogs. You can try to rinse in clean gasoline, if it does not help replace.
• In Chinese chainsaws (Gypsy), it very often cuts off the grooves on the main gear, through which the force from the sprocket is transmitted to it.

Principle of operation

The main unit of the system is the pump. The principle of its operation is as follows. With an increase in engine speed, a gear mounted on the main shaft drives the pump shaft through a worm gear. In turn, the rotation of the shaft creates a certain pressure in the oil line, which forces the oil to move along it towards the tire.

The end of the oil channel is located at the point of contact of the tire with the tool housing, where there is a longitudinal groove, on which, when the tire is installed, its oil channel falls.

The groove is necessary to ensure the supply of oil to the tire, regardless of the degree of chain tension of the chainsaw. Simply put, no matter what position the tire is in at the time of operation, oil will get onto it through the groove.

Further, a chain is included in the lubrication process, on the links of which, depending on the model of the chain, there is either a groove or a hole through which the oil is accelerated throughout the tire. With an increase in engine speed, the oil flow rate also increases.

Some models of chainsaws are equipped with pumps that additionally have a flow rate adjustment, and if necessary, the amount of oil supplied by the lubrication system can be increased or decreased.

This function is quite convenient, since it allows you to save money and not waste extra oil.

Lubrication system malfunctions and how they are eliminated

The main malfunctions of the oil supply system on a chainsaw can be divided into two main types, these are general malfunctions inherent in all chainsaws and individual ones, which may differ depending on the type of pump and worm gear installed on a particular model. Let’s start sorting out faults in order.

It is prohibited to use the chainsaw if the chainsaw is not lubricated. This adversely affects the tire, drive sprocket and chain, and can also result in serious repair costs.

Individual malfunction of the Stihl MS 180 lubrication system

In view of the fact that the Stihl MS 180 is one of the most common models of chainsaws, I would like to dwell on one inherent only malfunction and describe a way to eliminate it without replacing parts.

Quite often, on the Stihl MS 180 chainsaw, there is a depressurization of the oil line in the place where the oil line from the tank is installed in the saw body. The malfunction can be determined by the characteristic grease smudges on the bottom of the tool.

To eliminate the malfunction, it is necessary to remove the chainsaw handle, remove the hose from the bore, clean and degrease. After all these manipulations, apply a sealant to the hose seat and install it in the chainsaw body.

You can learn more about troubleshooting and full diagnostics of the Stihl chainsaw lubrication system by watching a video that shows step by step the process of disassembling and repairing the lubrication system.

The principle of operation and the device of the pump

Oil pumps can be made of metal and plastic. They are also divided into two types, which differ in their design:

The pump is driven by the movement of the drive sprocket. During the movement of the chain, oil is fed into a special channel located on the guide bar. At idle speed (when the drive sprocket does not rotate), the pump does not provide lubrication. this is done to save money.

The speed and volumes of lubricant supply to the chain are directly dependent on the number of sprocket revolutions. In some models of chainsaws, a manual adjustment system is provided using a special screw located on the body of the device. On expensive saw models, the oil supply is automatically adjusted during operation.

Chainsaw chain lubrication

Regardless of the type of chainsaw and the frequency of its use, caring for the saw and its spare parts is mandatory, because if you do not monitor the condition of the tool, it will very soon become unusable. Chainsaw chain lubrication, sharpening teeth, refueling the saw, checking the tightening of nuts and candles. this is the key to the long and correct functioning of your tool.

During long-term operation of the chainsaw, its chain may become dull, and the sawing will be much more difficult. Therefore, it is necessary to periodically sharpen and lubricate the chain on chainsaws. Chainsaw chain lubrication is carried out with a special oil (although automobile oil can also be used). When the fuel mixture is completely used up, it is important that a small amount of chain oil remains. Separately, I want to say about Oregon chainsaw chains. these chains are very durable. The long service life of these chains is achieved by features such as automatic lubrication. This is why Oregon chainsaw chains last long and function well.

Chainsaw chain lubrication

The only point that depends on the user is to make sure that the oil tank is not empty during operation. If this happens and the oil supply stops, the chain will acquire a bluish tint, which will indicate that it has overheated and has become unusable.

What to check before working with a chainsaw

Checking the tightening of the nuts should be done before each start of work with the chainsaw. The fact is that a tool such as a chainsaw has a lot of vibration, and because of this, the screws and nuts in it can loosen. Therefore, it is very unsafe to operate a chainsaw in which parts are poorly fixed.

Checking the candles of the chainsaw for carbon deposits (it should not be) also needs to be done, and if carbon deposits are found, replace the candle with a new one.

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Major problems with oil supply

When running a chainsaw, there are two types of chain lubrication problems:

• Insufficient oil flow, which can be caused for various reasons. If measures are not taken in time, the quality of work will noticeably deteriorate, and the chain itself may become unusable altogether.
• Excess oil.

Saw chain lubrication

The lubrication of the saw chain and bar is very important. The design of the chain saws includes a pump that supplies oil from the reservoir to the cutting system through special holes. Further, the saw chain itself distributes it. The grease is captured by the shanks and distributed throughout the entire bar and chain. For additional retention of lubricant in the chainsaw, special holes are drilled in the shanks or channels are milled. Also, in the chain lubrication system for chainsaws, connecting links are often involved, in which additional grooves are made for lubrication. Sufficient lubrication reduces friction and heat levels, thereby not only increasing the service life of each saw element, but also reducing the level of saw chain elongation. Therefore, it is in the interests of every saw owner to monitor the chain lubrication process so that in the event of a breakdown you do not have to look for new chains for chainsaws.

The lubrication process is quite simple: as the saw chain accelerates, small oil droplets form an oil trail on any bright surface if the end of the bar touches it. If there is no trace, there is no lubricant and you need to check the presence of oil, clean the groove of the tire, adjust the saw pump, etc.

And one more thing: in modern saws, it is allowed to install chains and bars of different lengths, but before using a new headset, you need to make sure that the oil pump installed in the saw will cope with its processing.

The task of the oil pump is to supply lubricant to the chain. this is necessary for its smooth movement along the guide bar. When the oil pump fails, the lubrication of the chain deteriorates, which reduces the efficiency of the chainsaw. In some cases, this leads to the breaking of the chain. To prevent negative moments, it is necessary to repair the oil supply in a timely manner. How to do it?

Malfunction of undefined category

In some cases, the owners of chainsaws have to solve more complex problems to fully restore the functionality of their cutting tool.

Chain wedges

This happens when the drive or driven sprocket wears out. The chain usually starts to wedge under load. But without load, the saw can rotate. The photo below shows a worn chain saw drive sprocket.

The next photo shows that the reason why the chain wedges must be sought in the location of the driven sprocket.

But what to do if the chainsaw is completely jammed and all attempts to pull the starter are ineffective? Such a malfunction sometimes occurs on Chinese-made chainsaws. It is caused by the bolts that have loosened from vibration, which screw the engine to the plastic casing of the unit. These bolts are located directly under the flywheel (magneto). In the photo below, the arrows show the location of the problem bolts.

When they twist, they begin to rub against the flywheel and can completely wedge the chainsaw. The following photo shows a flywheel with existing bolt scuffs.

To eliminate the malfunction, you will need to remove the flywheel from the engine shaft and tighten the bolts.

The main symptoms of a malfunction

How to find out in which mode your chainsaw is operating, whether it is working properly, or there are problems. In the worst case, the engine simply will not start, or it will start and immediately stall.

Defective chain lubrication system

• Leaks of oil, you will notice with the naked eye. In this case, you will need to check the junction of the pump tube and its fitting. Perhaps the cause of the problem is a leak, as indicated by cracks. You can eliminate the malfunction by replacing the tube and sealant.
• Insufficient oil supply, which may be preceded by clogging of the lubricant supply passages. The problem is solved by cleaning them.
• The presence of cracks in the oil pump, its housing. Only replacement will help.

DIY chainsaw repair: fuel supply system

If the fuel mixture does not flow into the cylinder, but the spark plug is working properly, this may mean that:

• Clogged fuel filter.

To clean this unit, remove the fuel hose and check the jet. If it is weak, the filter must be removed through the filler hole of the fuel tank and cleaned or replaced if completely worn out.

• Clogged breather.

This is nothing more than a hole in the fuel tank cap, which is cleaned with an awl.

• Fuel mixture not supplied or not supplied in sufficient quantity.

There may be several reasons for this:

• the air filter is clogged (in this case, it must be removed, rinsed with water, dried and replaced);
• the carburetor settings are out of order (which means this unit needs to be re-adjusted);
• the integrity of the carburetor membrane is broken (must be replaced);
• the channels of the carburetor are clogged (it must be disassembled and all parts and assemblies must be cleaned).

Principle of operation

When starting the engine and increasing its speed, the torque is transmitted to the shaft of the oil pump. The more you press on the accelerator, the more pressure in the oil line. the larger doses of oil flows through the oil line towards the saw headset.

Automatic chain lubrication system

The oil pipe ends at the point of contact between the crankcase and the guide bar. As we already mentioned, it has grooves and an oil channel through which the lubricant flows to the chain. The saw chain itself also has grooves that disperse the oil throughout the tire.

Some newer chainsaw models are equipped with oil flow regulators. This is a convenient function that allows you to increase or decrease the lubricant consumption, depending on the ambient temperature and the intensity of work.

Chainsaw does not idle

It often happens when, after long transportation and constant use, the chainsaw refuses to idle smoothly. This problem is usually corrected by adjusting the carburetor.

You can learn how to properly debug the carburetor from this

If the carburetor is tuned like a clock, then you need to check:

• Fuel system. It makes more sense to start with the fuel pump.
• Muffler. Chances are high that due to the abundance of accumulated soot, the engine may not function normally.