How chainsaw chain is lubricated with oil

chainsaw, chain, lubricated

Husqvarna chain saw oil adjustment

A chainsaw is a tool with a two-stroke carburettor engine. For quality and long time chainsaw requires not only fuel. gasoline, but also lubricants, i.e. oil. All technological oils regardless of the principle of action and scope of application serve the same purpose. quality engine work, lubrication of leading engine parts, durability of parts, reduction of parts wear.

The important thing is! Motor oil for mixing with gasoline to fuel a chainsaw and chain oil for chainsaw chain lubrication are not the same!

The ideal chain oil for chainsaw chain lubrication must meet these requirements:

  • be of high quality, preferably of a well-known world brand or “native”, which is produced by the manufacturer for its chainsaws;
  • Have good adhesive properties, i.e. spread evenly and tightly over the whole area of the chain and the contact area of the chain with the bar;
  • meet the viscosity specifications for the time of year
  • not smoke-forming;
  • Withstand cold temperatures and do not freeze in freezing temperatures, which is especially important in winter.

How to use chain oil for chainsaw chain lubrication?

A special pump is provided to grease the chain in a chainsaw or electric saw. This pump should supply oil directly to the bar, distribute it over the chain and let the chain work properly. The degree of oil consumption depends directly on the number of engine revolutions. the higher it is, the greater the consumption.

What is the forced lubrication system?

STIHL chain saw lubrication system and this unit in other power units is identical, depending on the speed and number of revolutions of the chainsaw heart, the engine. Oil is metered at the cutting element, or more precisely, the bar. This is made possible by a special pump.

The chainsaw chain lubrication pump sends a consumable with high adhesive properties to the saw unit. only use high quality consumable material, because only this material can distribute evenly over the entire bar, even at maximum revolutions of the chain mechanism.

Design of the lubrication system

The chain chain lubrication system of a chainsaw, taking into account the manufacturer of the tool, may differ slightly in design features, by the parts used in the creation of this node. In this case, the features do not affect the wiring diagram of the system, as well as the total number of parts used.

  • oil reservoir located in the engine crankcase;
  • tank filter (element located directly in the tank)
  • the oil line, which looks like a small diameter hose made of high-quality rubber;
  • The pump itself can be considered the heart of this assembly;
  • engine power supply to the heart of the unit. worm gears (worm gears).

In some works by powertrain repair specialists, the guide bar is described not just as a saw headset, but as one of the components of the lubrication system. Why so? This can be explained by the presence of special holes in this rail, through which the oil is fed. By the way, the chain itself can be considered a participant in the transportation of lubricant consumable, because this mechanism also has parts related to oil distribution.

How does this assembly work??

The heart of the assembly is the pump, consider the principle of its operation.

  • As soon as the engine speed increases, the pinion of the main shaft with the help of a worm drive makes the pump shaft work.
  • When the pump shaft works, pressure is created and transferred to the oil line, which pushes the oil towards the tire.
  • The end of the lubrication channel is located at the junction of the power unit crankcase and the guide rail, where the longitudinal groove is located. The lubrication channel runs on the last one.

What function does the groove perform?? It provides the oil flow to the guide bar, no matter what the chain tension level is. This ensures that the oil gets to the guide bar even if it is not in the normal position for operation.

Do not forget that the chain mechanism takes part in the lubrication process. The tire chain, depending on design, has holes or grooves through which the lubricant is distributed over the tire. Oil will flow to the bar faster as soon as the engine speed is higher.

Certain models of the tool have pumps that can be additionally adjusted (the operator will be able to adjust the capacity of the pump, depending on the amount of work and operating conditions of the saw). If there is a need, the oil flow is reduced, if it needs to be increased, the appropriate adjustment is made.

Be sure to read our article on the STIHL chainsaw chain oil system. System settings may vary depending on chain saw brand.

The main advantage of this function is that it saves consumables. By the way, if you are interested in what oil to pour for chain lubrication chainsaw, choose what is recommended by the manufacturer of your power unit.

Oil selection criteria

Many chain saw owners, when malfunctions occur, blame the tool Manufacturer, complain about cheap components and low-quality assembly. However, it is often the owner’s own negligence and desire to save on consumables, particularly oil, that leads to the breakdown.

And some people even go to a garage and beg for a liter or two of recycled oil. These savings then translate into relatively high repair costs for the chainsaw and the purchase of new chain and other parts.

Chainsaw chain oil selection criteria:

  • Viscosity Index. This term describes the extent to which the oil’s viscosity changes at different temperatures. It is better to use oil with the index from 90 to 130. And the pour point should be at the right temperature.30 0 Celsius. Viscosity varies with temperature:
  • Viscosity at 40°C: 100 mm²/s DIN 51562
  • Viscosity at 100°C: 13.5 mm²/s DIN 51562

These criteria are met by oils from well-known brands like Liqui Moly, Dynamic, STIHL, Husqvarna.

Important characteristics to consider when choosing oil:

  • Versatility. Many chain saw owners prefer to use an all-purpose oil for chain lubrication. This is not a good decision. The temperature difference between summer and winter operation can be as much as 50 degrees Celsius. You are unlikely to find a mid-priced oil that can reliably protect your chain. Use different types of oil for winter and summer operations;
  • Additives. It’s not a good idea to put regular motor oil in the lubrication system. The fact is that chainsaw lubricant manufacturers add special additives to their products that provide more reliable chain lubrication. In fact, the oil droplets literally stick to the bar and chain;
  • Thickness. Another reason why you can’t use conventional oils. If you notice drips around the oil reservoir, you may need to buy a quality oil designed to lubricate the chain in your chainsaw;

Important: Many users say that they successfully use mineral gear oil with a viscosity 15-40 for summer and 10-30 for the cold season. They can be used for some time, but temperature requirements must be adhered to and the oil line must be kept clean.

Advantages of high-end oil pumps

The repairability of demountable pumps is sufficient to restore the unit to working condition at home.

Gears of the pump drive of budget chainsaws are mostly polymer. Technically advanced, brand-name models with adjustable output are equipped with drive mechanisms made of non-ferrous metals. Cost of such systems is compensated by economical, up to 50% working fluid consumption.

Lubrication system design

Depending on the chainsaw brand, parts of the lubrication system may vary slightly structurally, but their overall number and connection scheme remains the same.

The main components of a lubrication system are:

  • oil tank usually located in the engine crankcase.
  • The filter element, installed in the tank.
  • The oil pipe is a small diameter hose made of oil-resistant rubber.
  • The heart of the system is the oil pump.
  • The worm gear gear that transmits power from the engine to the pump.
  • The chain saw bar, it too can be considered as an element of the lubrication system, because it has special holes for the oil flow; by the way, the chain itself also takes part in the oil transfer and, respectively, also has some elements designed specifically to provide lubrication.

Chainsaw oil pump: malfunctions and repair

As we said before, the principle of operation of the chain lubrication system is the same for chainsaws and electric saws. Therefore, it is clear that malfunctions associated with the oil pump, as well as the causes of their causes, will be the same. A chainsaw oil pump malfunction can manifest itself in just two ways oil doesn’t come in enough or leaks where it shouldn’t. Let’s dwell on the symptoms of a chainsaw oil pump malfunction and talk about the possible causes. And let’s mention a few solutions.

Insufficient oil supply to the chain. Insufficient lubrication leads to overheating and chain pulling. This can cause the chain to jam and more dangerously, it can slip off while the saw is operating. There may be several reasons why a pump is not delivering enough oil.

  • The simplest and easiest to pinpoint is a clogged channel that delivers oil to the chain. Sawdust and other debris clog these and prevent proper lubrication of the chain. That’s why it’s important to clean the outlet channel and the channels on the bar where the oil flows in a timely manner.
  • Another reason is the chainsaw’s oil pump plunger is malfunctioning. Plunger turning takes in a certain amount of oil and sends it to the chain. Plunger RPM directly depends on engine RPM, that is, the faster the chain spins, the more oil needs to flow to the chain. If the plunger breaks, it has to be replaced.

Oil dripping. You should be aware that small oil leaks are not a problem. However, if you find your chainsaw in a puddle of oil every time, it’s time for repair.

  • First check the tightness of the oil pump tubes and fittings. The tubes can crack over time. It is best in this case to replace them with new ones, but you can try to seal them with a special sealing material.
  • If the cause of the problem is a crack in the body, you will have to buy an oil pump for a chainsaw repair such defects are not repairable.

It is impossible to ignore wrong functioning of oil pump for a chainsaw. However, there may be several options for solving the problem. Correct diagnostics and determining the cause of malfunction is a guarantee of speedy problem solving.

Your manual should be your best guide. If you lose it, you can go to the dealer of the company whose chainsaw you use, they will give you the instructions electronically.

So, before starting up your chain saw, always make sure the chain is in good working order, its teeth ground and tensioned (no slack, but also not too tight, it can be pulled away from the blade).

You can sharpen the chain with a special machine or file with a special template (there are different templates, depending on what is the tooth pitch of the chain).

Every time after use you must clean your chainsaw: chain, bar, air filter, body, cooling fins, slots and other grooves. After using the saw, turn the guide bar so it wears evenly, lubricate the sprocket (if there are slots for lubrication in the front of the saw).

Always drain fuel and oil before storing for any length of time! The chain and bar form an electrochemical pair, so they corrode together and should be stored separately.

Roman:

I have a Husqvarna 345 and found a problem with the oil flow. Both sides were covered in oil and I can’t tell where it’s coming from. On advice of friends, disassembled saw, cleaned, rinsed and checked. The hose is blocked and it’s not coming through the bar, but splashing around.

Nikolai:

The oil flow on the power saw has deteriorated. Started to figure it out, put a new pump, but nothing changed. Took it to a specialist and it turns out that the problem was with the oil pump actuator. It was replaced and everything was fine.

How to prepare the fuel mixture

Dilute gasoline with oil in a petroleum-resistant container (plastic or metal canister). It is not recommended to use plastic bottles from water, juice, or milk for these purposes, since plastic foodstuffs decompose under the influence of gasoline. The mixture will change as a result of this process and it is difficult to predict its effects on the engine.

It’s easy to make chainsaw fuel mix.

  • Take required amount of lubricant and pour it into prepared container. Do not pour all ready-to-use petrol into the oil-filled container. half the required amount will suffice.
  • Shake the container a little until the lubricant is completely dissolved in the gasoline.
  • Now you can pour the remaining gasoline, mixing it well with the mixture in the tank. This is the end of making fuel mixture for a chain saw.

Before each filling of the chainsaw, always shake the fuel mixture. Also do not forget to tighten the lid of the fuel tank well, otherwise it will lead to depletion of the mixture and engine failure.

It is better to use immediately the ready fuel mixture. Therefore, prepare it in such an amount that it is enough for the intended amount of work. If there is still mixture left, it should not be stored for more than 1-1,5 months. During this time, it will lose much of its lubricity.

How a carburetor works

The carburetor serves to mix the combustible consistency with the air, while respecting the predetermined proportions. If precise dosages are not respected, the functioning of the engine is endangered. When the component gets a huge amount of air and not enough fuel during mixing, it is considered lean.

Do not allow oversaturation, because a large amount of fuel compared to the air is also likely to malfunction or wear on the engine. Adjusting the carburetor is needed not only before initial implementation, and when you identify any differences in his work. Before working with the chainsaw, be sure to run it in.

The design of the carburetor has a standard set of parts, but may vary slightly depending on the manufacturer. Components:

  • Basics. This is a special tube, which visually resembles an aerodynamic design. Air flows through it. There is a slide valve in the transverse direction in the middle of the pipe. Its position can be adjusted. The more it is extended into the passage, the less air enters the engine.
  • Diffuser. It is the narrowed part of the pipe. It increases the airflow speed exactly at the place where fuel comes out.
  • Channels for fuel supply. Fuel mixture is contained in the float chamber, then it goes to the nozzle, from which it flows to the atomizer.
  • Float chamber. Is a separate constructional element, resembling the shape of a tank. Designed to keep the fuel at an optimal level before it enters the channel where the air comes from.

Not sure which chainsaw to choose? Read our article.

Looking for cheaper models, but reliable and time tested? Pay attention to chainsaws made in Russia.

Or look at foreign chainsaw makers like STIHL.

What chains for chainsaws can be?

Depending on the intended use, that is, on the planned direction of sawing wood, chains for utility saws are divided directly into these types;

  • longitudinal. the peculiarity of this type of headset is that when it is mounted and used on a garden tool, the performance of the latter increases by almost 2 times;
  • cross. by installing a cross headset with pobedite tips, the chainsaw operator is able to significantly reduce the “aggressiveness” of the garden tool and reduce the load on the built-in factory motor, thereby making the vibration of the internal combustion engine less noticeable.

Another important parameter for stable operation that chains are constantly divided into is their pitch. Chainsaw chain pitch is the length of the gap between the three links.

On the market there are headsets with such pitch characteristics:

  • 0,25 or 1/4″. these parts are included in single-handed household saws that do not have high power. This type of garden tool is most often used for precision cutting of wood and for short periods of work in very confined spaces;
  • 0.325 or 3/8″. Most chain saws of this type are equipped with this headset;
  • 0.404 or 3/4″. carbide saw elements of this type are large in size. They are mounted exclusively on powerful professional garden tools, which can be used for working on aerated concrete.

All of the available sawing parts are made with the assumption that the bigger the size, the better the cutting performance. Nevertheless, as the dimensions of the sawing elements increase, so does the cutting width. To make the resistance of the material to be sawn less noticeable, only saws with an impressive power margin should be fitted with large heads. quite often manufacturers divide saw elements according to their shanks thickness, which must necessarily coincide with designed dimensions of regular tire grooves of garden tools. Observance of this rule will improve the reliability of fixing the part on the tire, and will prevent slippage of the headset.

Another important parameter is the number of headset links. The higher the number, the faster the gasoline saw will cut hard wood or perform concrete work.

What to replace the original expensive oil and is it worth it

In situations where it is not possible to use the original, you can replace them with oil for car engines. Cheap automobile oils like motor oil or diesel variants of grease, because of low adhesive properties, are unsuitable for long-term use.

Some owners, in spite of recommendations, still use analogues, preferring to change the bar and chain more often, but here everyone decides for himself. Such oil cannot have any adverse effects on the lubrication system, which means the difference is only as a protection for the tire from chain friction.

Adjusting the Chain Oil Flow of a Husqvarna Gasoline Chain Saw

A chainsaw is a tool equipped with a two-stroke carburetor engine. For chain saws to work properly and for a long time, not only fuel. gasoline. is needed, but also lubricants, that is, oil. All technical oils, regardless of the principle of action and scope of application serve one purpose. quality engine operation, lubrication of leading engine parts, durability of parts, reduction of wear of parts.

Important! Engine oil for mixing with gasoline to fuel a chainsaw and chain oil for chainsaw chain lubrication are not the same!

The ideal chain oil for chainsaw chain lubrication must meet these requirements:

  • Be of high quality, preferably of a world famous brand or “native”, which is produced by the manufacturer for its chainsaws;
  • have good adhesive properties, i.e. spread evenly and tightly over the whole area of the chain and the point of contact of the chain with the bar;
  • Meet the viscosity standards for the time of year;
  • not smoke-forming;
  • be able to withstand low temperatures and not freeze in freezing temperatures, which is especially important for winter operation.

How to use oil for chainsaw chain lubrication?

A special pump is used to force lubricant into the chain on a chainsaw or electric saw. With this pump, the oil should be fed directly to the bar, distributed over the chain, contributing to the quality work of the tool. The degree of oil consumption depends directly on the number of engine revolutions. the higher it is, the greater the consumption.

Oil system

STIHL chain saws have a special system that supplies oil to the chain. The patented OILOMATIC system, found on various STIHL chainsaw models, is an exclusive feature. This is an unusual extra not to be found on every other makes of chain saw. and more people choose STIHL saws for this reason. What is this system? This is a specially designed groove designed to direct oil to critical wear areas. This superior lubrication feature gives the customer extended chain life with reduced tendency to stretch.

A further development of the OILOMATIC system is the oil reservoir next to the OILOMATIC channel These reservoirs are filled with oil when the drive links pass through the inlet of the guide bar and are emptied by the centrifugal force acting on the bar nose. This ensures more oil is distributed over the chain, groove and rails. The system protects the saw from premature wear. Simply put, it directs the oil where it is needed. The system is available on all STIHL saw chains.

Customers sometimes report a problem with a STIHL chain saw chain that is not lubricated. This phenomenon is rare. STIHL chain lubrication systems control chain lubricant consumption compared to conventional saws without the Ematic system. Special system reduces consumption by up to 50%, depending on the type of wood and the cutting attachment used. This system includes the STIHL Ematic or Ematic S, the STIHL Oilomatic.

Anyone interested in learning more about the German-made chainsaw, here is an overview and specifications of the STIHL 180.

Every model is equipped with a variable-flow or reduced-flow oil pump. Virtually every drop of chain lubricant is delivered precisely to the right place. This system reduces friction and wear and therefore prolongs the life of the cutting attachment. Oil channels (funnel-shaped) in the saw chain connect the oil directly to the rivets and cutter bar steps. Several recesses into which chain oil can collect are also stamped into both ends of the drive links. This allows a better distribution of oil over the sliding surfaces of the guide rods.

Possible problems

  • STIHL chain saws often have the same criticism as the STIHL Rollomatic ES models (STIHL EmaticSuper) when it comes to not getting oil to the chain. This model consists of a solid and particularly rigid nose bar that can be replaced completely. That’s why it is ideally suited to the most demanding professionals, different applications and mainly used for heavy-duty work. Elliptically shaped, angled oil holes increase the chain oil flow rate for optimum lubrication and long guide bar life.
  • Oil flow problems are often the result of improperly filled machines. It is important to follow the manufacturer’s instructions and requirements to avoid problems. STIHL chain oil with 2 cycles. They are high quality, conventional petroleum-based engine oils designed for the highest levels of engine performance.

Oil provides protection in today’s high-performance, air-cooled two-stroke engines. The environmental acceptability of chain saws and power tools is also greatly improved with BioPlus lubricating oil (BlueAngel winner). It is not only biodegradable, it is also environmentally friendly.

Here is an in-depth look at the popular STIHL 250 chain saw and its specifications.

STIHL 2-cycle oils are designed for the high temperatures and conditions of today’s innovative and technically sophisticated engines. All STIHL 2-cycle oils contain a fuel stabilizer for longer storage life. STIHL recommends a 50:1 mix of high quality 89-octane unleaded gasoline. The same mix ratio should be used during breakdowns.

What do the people who use STIHL 2-cycle oil saws say about it?

“Inspect the clutch drum and return threads. Inspect the pump bracket. Make sure the housing (under the threads) that holds the pump is not clogged or damaged. If that’s the case, sometimes marine epoxy can fix it.”.

“The most common reason for the system to fail is that it is blocked. You must remove the handle. remove screws, external plugs. You will see a hose from the tank. pull it out. If it is broken, you have found the problem. Flush the reservoir, hose and pump inlet.”.

chainsaw, chain, lubricated

Signs of a faulty lubrication system, are as follows:

  • the chainsaw chain is completely dry and not shiny;
  • oil is not coming out of the oil tank;
  • The chain is stretching fast and it happens all the time;
  • Saw guide bar can swing out to the side during cutting;
  • the tire warms up and in the area of the drive sprocket, melting of the paint is observed.

All of these signs, directly or indirectly, point to problems in the chainsaw chain lubrication system.

The first thing to do after you suspect the chain lubrication oil is not coming in is to check the oil flow. There are two ways to do this. The first way is described in detail in the instruction manual of your tool and is as follows: start your chainsaw, increase gas pressure as much as possible and direct it towards some obstacle.

If the tire has a good lubrication system, oil will be coming off the tip and a streak of oil droplets will be visible on the surface where the tire is facing. If there are any irregularities in the system, the surface will remain clean.

The second way is to remove the bar from the chainsaw and start it up. The oil flow from the oil channel will increase as the engine speed increases, at the place where the guide bar is installed, if not, you must look for the cause of the fault.

Diagnose

Start by inspecting and checking the STIHL 180 oil receiver (filter). If the oil filter is very dirty it can stop the flow of oil.

3 Easy Ways To Check If Your Chainsaw Is Oiling The Bar & Chain. Video

In the interest of economy, a clogged filter, you can try to clean it by washing it well in gasoline.

Next, it is necessary to remove the sprocket drum, and check the condition of the drive pinion. The threads on it should be clearly marked, not nicked and have no other defects, also with the removed gear, it is necessary to check the wire lever. It should be able to crimp the pinion tightly and not turn, otherwise the pinion will not turn and will not transmit power to the pump, which would stop the flow of oil.

If all of the above methods to detect and troubleshoot fail, it is necessary to apply extreme measures, i.e. е. dismantle the pump.

How to Remove the Pump

The oil pump is mounted on the right side of the base of the housing and the oil pipe from the chainsaw tank is connected to it at the same place. To remove the pump, you will first need to release the saw from the handle, for this unscrew the back handle of the unit and disconnect the throttle control rod. The next step is to remove the handle buffer plugs and use a strong slotted screwdriver to press them out of their housings in the handle.

Read also How to castrate a piglet correctly video

After removing the handle, the chain saw body is turned upside down. The hose that goes from the oil tank to the pump will be visible at once. It must be removed from its seat.

The pump itself is dismounted with an M5 threaded screw and a broad washer. The length of the screw should be about 45-50 mm. A washer is put on the screw and it is screwed into the pump (the inside of the pump is threaded). Next, as the screw is screwed in, a stop from the washer, will force the oil pump up the thread. That’s how the pump is removed from its seat. Before you start, we recommend reading our article on how to disassemble the STIHL 180.

For a better understanding of the process of removing the pump, you can watch the video below. In this video the STIHL service technician shows in detail how to remove the oil pump from the chain saw and shows the main faults in the feeding system.

The STIHL oil pump is a quality and robust piece of equipment and should only be replaced when all other system components have been tested.

After the pump is removed it should be cleaned and blown out. As a rule, the main breakdown of the oil pump is its clogging. After clearance, pump can be reinstalled.

Pump only needs to be replaced if blockage cannot be corrected.

The reason for the oil leak on the bottom of the chain saw

STIHL 180 chain saw has a defect in that the oil hose is not properly sealed in the chain saw housing and is leaking. To fix it, simply remove the STIHL MS 180 saw handle, disconnect the hose, wash and degrease the seat in the housing and the hose shank, then apply sealant and put the hose back in place. This simple procedure will reliably take care of the problem and the oil will stop leaking.

chainsaw, chain, lubricated

Chain lubrication. Possible problems and troubleshooting. Do-it-yourself repair

You might even say it does not apply at all. They all work the same way.

The main parts are an aluminum cylinder rigidly mounted in the housing and a steel plunger with a plastic gear that rotates in this cylinder. How it works: There’s one small hole at the blind end of the cylinder. There is another one opposite.

One is suction and the other is discharge. There is an oblique circular groove in the plastic plunger pin that aligns with the metal rod in the body.

Mechanics: When the plunger rotates due to the oblique groove, it also reciprocates back and forth on each revolution.

Hydraulics: As the sheared portion of the plunger end approaches the suction port, the plunger is retracted. A small vacuum is created and a small amount of oil is sucked into the cylinder.

Turning the plunger about half a turn the sheared section (with the oil in it, of course) approaches the discharge port.

At this time, the plunger moves towards the blind end of the cylinder. Some pressure is created, oil comes out in the lubrication channel.

Now for the differences in design: The pinion on the plunger can be metal. In this case the worm on the crankshaft will be plastic, there is no way around it, there must be a weak point.

The pump casing can be made of metal. Well, not bad, of course, but not fundamental. And most importantly, the oil flow adjustment. In the first case, where the plunger axial movement is driven by an oblique annular groove.

Performance adjustment is not technically possible.If the longitudinal movement is made by the oblique cut of the back of the plunger, it is possible to adjust the feed.

With different variations of the adjustable rear plunger stop, the length of its axial movement changes, and, accordingly, the amount of oil captured per plunger revolution. _

how often do you have to grease a chainsaw tire?? And I understand that the grease should be about the consistency of lithol? Or the same transmission is acceptable?

After 1 or 2 fill ups of gas tank. In addition to special sprocket sprocket greases, you can use lithol or similar consistency bearing greases commonly available in auto parts and accessories stores. Transaxle grease is too thin for this. _

Bought a new chain, installed, works great. But after a couple of minutes, the hole in the bar for the oil supply, clogged, and the chain goes dry.

Literally enough for one shear. Disassembling again, cleaning, starting up. Without sawing, the chain is lubricated. And after one cut, tire is clogged with shavings again.

Gasp did not try, because not had time, the chain almost jams, hand does not scroll, and the tire and the chain is terribly hot, gasoline chain stalls. Please tell me what the problem is. I never had this problem with my old chain?

A great suspicion that in fact it is the oil for lubrication, only because of the large amount of dust (perhaps now sawing dried up wood, or even with the chaff) getting into the groove of the bar and on the chain it is not visible.

What is the condition of the tire itself?? Particularly important here is the condition of the sprocket and the tire spacers (on which the chain slides during operation) in places where the sprocket teeth dive into or come out of the tire as they rotate.

Also, if the spacers are excessively worn, the tire groove depth may have dropped below the allowable level and the chain shanks are catching on the bottom of the groove when you move it.

In this case, too, there will be excessive heating of the chain and tire. It looks like this is not the first chain you’ve used on your tire.

Also, the fact that the chain stops when the chain jams indicates a non-functioning clutch. There is either dirt between the clutch cams and the clutch cup, or the cup is deformed. Maybe the clutch springs are stretched.