How to tension the chain correctly on a STIHL chain saw

When to retighten the chain

Never work with a very slack chain.

A chain that jumps while sawing can break the bar groove, disrupt the teeth of the sprocket.

A slipping chain can damage parts of the machine. But the most dangerous thing is injury to the operator. In spite of the brake and catcher bar, a loose chain can whip around on an unpredictable path, and this is extremely dangerous.

Always check tensioning before you start work. There are two signs which are indicative of critical looseness during operation:

If this is the case, switch off the engine and check the tension.

How To Adjust Your STIHL Saw Chain

How to determine chain size and pitch

There are three single important parameters for chainsaws and electric saws:

Table 1 shows the distance between the rivets, which will allow the owner to correctly determine the chain pitch. In addition, the instruction manual of the original electric saw or chainsaw will necessarily indicate the pitch, length, number of chain links.

Total chain length depends on the exact number of teeth on the inside. It is necessary to count the number of drive links and this is the chain length.

Example: For a 40 cm bar you can use chains with different numbers of teeth, e.g. 57, 56 or 55. the number of teeth will depend on the model.

It is a mistake to assume that the same chains can be put on all 40cm long bars.

It is also important to know the thickness of the shank (drive link). The shank holds the chain on the bar. To understand how to measure the thickness of this part, see table 2.

Table 2. Shank thickness.

The most common chain pitch for non-professional chainsaws is 0.325″. Such chains are ideally suited for chain saws up to 2500 watts. It is better to select a chain not on your own, but with the help of a salesman or a specialist who works with components for chainsaws and electric saws.

Purpose of chainsaw chain

The main task of this part is to cut wood, stone and other materials. Consists of multiple connected chain links with specialized teeth. As for the alloy, for the production of all (including professional) use metal with similar characteristics, but one chain can be very different from another.

The distinction, however, is as follows:

• By Length. Each variety is designed to fit on a specific bar.
• By pitch (distance between rivets). Increasing it has a positive effect on performance, but increases the impact on the engine.
• According to the size of the shank. It varies from 1.1 mm to 2 mm.
• By height and shape of teeth (high and low profile). The quality of the cut and the classification of the work depends on this point.

Important! It is a good idea to periodically sharpen the cutters with a file or suitable tool. A blunt blade will put additional strain on the engine and increase fuel consumption.

Also, over-tensioning a chainsaw chain will shorten the life of the motor.

It is not difficult to make a diagnosis. To do this, take a link and pull it up. If the chain “tails” protrude by 1/3 or 2/3 of the total length, they are adjusted correctly and are considered to be acceptable. It’s also a good idea to check the movement of the chain by hand. It should rotate smoothly without cracking or jamming. If it passes the tests you can start to fill up your saw. It usually uses gasoline mixed with oil, and the proportions are specified by the manufacturer. Maintenance also includes lubrication of all moving parts. Otherwise, even a good quality and new saw can break after 3-5 hours of sawing.

Reasons for chain slackening on a chainsaw

A chainsaw consists of the bar that drives the blade and the chain itself. Each of these parts can fail, affecting the operation of the mechanism.

There are several reasons why a chainsaw chain needs to be tensioned. Even with a tensioned roller, after sawing a few logs, you may encounter sagging of the element. The main reasons for the appearance of the fault are:

Link stretching occurs constantly, which is due to the nature of the design. To perform its task, to follow a pre-defined path and to cut through wood, it consists of a number of angularly and sharply sharpened links. They are connected to each other by bushings. There is play, looseness between them.

As the temperature of the metal rises during operation, this play increases, the steel expands and lengthens, and the working blade deforms.

Potential problems of some parts of the design cause disruption of others, as they are combined into a system. That is why it is important to pay attention to the malfunctioning of the saw at the outset, to replace the broken part or to adjust it in good time.

Possible causes of stretching the main part of the chainsaw can be working in adverse conditions (ingress of dirt, dust), improper operation of the oil pump (no lubrication of the links), the use of low quality material.

The bar is loose

Guide bar on electric chain saw. The bar is made of stainless steel whose operating characteristics influence the product’s longevity. When worn out, the part must be replaced and cannot be repaired. If a tire is loose, it is often due to webbing overheating, which can occur for several reasons besides age of use:

In addition to changing the parameters of the guide bar, the work area itself can be stretched. As the main part of the tool, it is directly responsible for the quality of the cut.

The chain is stretched

The probability that the working area can sag is greater with a new design or after long periods of use. Causes of stretching can be:

The longevity of the metal belt depends on the operator’s operating style. If a household tool is used with a heavy load, the service life is shortened.

Problems with the drive sprocket

The chainsaw is designed so that the engine must transfer power to the belt, where the teeth are. A sprocket-shaped part is designed for this purpose. It receives, stores and transmits power from the engine continuously and becomes hot during operation. the service life of a drive sprocket is affected by the pitch of the teeth, how they are angled, and how well they are ground.

If you do not make the chain tensioning on the chainsaw in time and do not replace the part, it is fraught with expensive repairs:

• the blade begins to cut in a curved path;
• the load on the motor is increased, which increases the risk of motor failure;
• the clutch spring breaks;
• The piston of the tool’s engine becomes deformed.

The saw’s instruction manual specifies the standards at which a part of the mechanism is operated. If deviation exceeds 0,5 mm, sprocket needs to be replaced.

How to tension the chain on a chainsaw correctly

The chain performs two functions at once. it directly cuts wood and fixes the bar, preventing it from moving arbitrarily. Proper chain tensioning and correct positioning of the chainsaw chain is important for proper use of this tool and prevents dangerous bodily injury during cutting operations. If the saw headset is not installed correctly, it can easily fly off during sawing, injuring the operator. Even with a slight loosening, it gradually breaks the groove of the bar, which leads to the failure of the teeth of the driven sprocket.

Excessive stress leads to increased load on the rotor, reducing the service life of the saw. Therefore, it is important to regularly check the tension, if necessary, to tighten the special mechanism on the body of the tool.

Important! Slackness can be caused by worn components. Usually it is a rubbing of the sprocket teeth, breakage of the outer edge of the bar groove.

How to fit the chain and guide bar onto your chain saw: assembly

The procedure under consideration is quite simple. It is characterized by the following features:

• You start by releasing the chain brake.
• The tensioning screw is in close proximity to the guide bar.
• The next step is to tighten the cutting element in a clockwise direction.
• If the chain is difficult to move, the screw must be loosened.

Modern chainsaw designs make such work much easier. So you can do it yourself even if you don’t have any special tools.

Tensioning algorithm

Before tightening the chain on a chainsaw, you must turn off the engine of the machine, or unplug it if it is an electric saw. Do not adjust or replace the saw element if it is in a heated condition. If you do this, the metal will shrink after it cools and the tension will be too great, which can put more stress on the engine and deform the tire.

The chain tensioner is located on the right side of the machine, under the cover, where the clutch brake is installed and the tire mount is. On Husqwarna, STIHL, Poulan and Partner chainsaws, the tensioner looks like a bolt.

So in order to adjust the chain element of the machine, you need to do the following.

Slightly loosen the nuts on the right cover to keep the bar from twisting.

On Makita electric saw the tensioner is designed so that you can turn it without using any tool. Turning it clockwise will tighten the chain, if you turn the regulator in the opposite direction, the tension of the chain element will be loosened.

Trouble with the clutch

Failure	Possible reason	What to do
Chain spins without stopping, with all carburetor adjustments. The engine does not run steadily.	Spring in clutch drum broke.	To remove the spring and replace it with a new one, or install a new assembly.
The chain spins almost constantly, making strange noises.	Chipped cam.

Reasons why the clutch needs to be disassembled:

• Faulty or broken spring;
• As a result of chainsaw loads and component wear, the spring has left its place;
• Chipping on clutch plate;
• Wear on parts.

Chainsaw replacement

If your chainsaw chain needs to be replaced, follow these steps.

• Remove sprocket cover. To do this, most often the fastening nuts need to be unscrewed.
• With the fasteners unscrewed, remove the cover covering the sprocket clutch.
• Holding the bar in your hand, push it toward the sprocket to loosen the chain.
• Remove the chain element from the drive sprocket.
• Now place the chain on the chain saw. Take the new saw blade and put it on the drive sprocket first.
• Then you need to put the chain on the bar, laying the element in its groove all around. It is important that the links fit correctly on the drive sprocket, which is on top of the bar. Note the direction of the cutting links when installing. They must point in the opposite direction from the machine, on top of the guide bar.
• Feed the bar in the opposite direction to the engine to tighten the chain slightly.
• After positioning the blade, before replacing the cover, align the screw for tensioning adjustment with the adjuster which is behind the guide bar. Only after that can you fit the cover and tighten the nuts slightly. Next, insert a screwdriver into the adjusting screw and perform final tensioning. How to do the correct chain tensioning was explained above.
• Lift the tire slightly and tighten the nuts, thus securing it. It is important not to overdo it and break the thread.