Replacing the piston group of a Chinese lawn mower (43-52cm³) – Forward, Redverg, Patriot, etc.

What is a fuel mixture and how to prepare it?

Although many people simply pour gasoline into the tank first, and then oil, and lightly shake the mower, we will do everything right for the new unit. To prepare the fuel mixture for the Fubag lawn mower, 92-octane gasoline and a special semi-synthetic motor oil designed for 2-stroke air-cooled engines are used.

Please note that oil for water-cooled engines (boat engines) and oil for 4-stroke engines are not suitable here - they form carbon deposits on the spark plug, clog the exhaust port and damage the piston. For our engines, we recommend Fubag 2T Extra semi-synthetic oil - an optimally selected high-quality composition.

The recommended proportional ratio of oil to fuel mixture is 1:40, that is, for 1 liter of gasoline you need approximately 25 grams of oil, this can be exactly the volume of a standard cap from an oil container. In the case of a fuel mixture, oil can ruin the porridge, because... excess slightly increases the smokiness of the mixture during operation, and therefore carbon deposits.

Not adding oil is also not good, because... Lack of lubrication critically affects the service life of 2-stroke engines.

Before refueling the Fubag gas trimmer. This mixture must be thoroughly mixed in a separate canister, and only then poured into the gas tank. The quality of mixture preparation directly affects the engine life of a gasoline trimmer. Therefore, do not use fuel mixture prepared more than two weeks ago. This may lead to premature failure of the unit.

Pour the mixture into the gas tank, it is advisable to fill it no more than 80%.

On our trimmer, the tank is translucent, which makes it possible to monitor the amount of mixture by eye. it is very comfortable!

By the way, there is a reminder on the fuel tank - so you won’t forget.

EXPERT TIP: Under no circumstances should you store gasoline in a plastic water container. When mixing the fuel mixture, a static charge accumulates and a spark can be caught.

— Assembling the braid

So, first you need to properly assemble the lawn mower. It's very simple.

1) Connect the rod and the motor. To do this, we align the rod relative to the engine so that the spindle is located in the same plane with the engine fuel tank.

2) Install the rod flange into the engine and secure it with 4 screws.

To do this, you need to unscrew the thumbscrew on the top cover of the fastener. And remove the top cover. Next, insert the handle into the fastener, install the cover, and tighten the screw. We put the control handle on the pipe and fix it with a screw. On this trimmer, the adjusting screw allows you to adjust the handle to suit the user: you just need to loosen the “thumb” and move it to the required distance, and then secure it.

READ Which electric grass trimmer is better?

Connect the throttle cable to the engine and insert its end into the throttle joint. Connect the red wire of the control handle to the red wire of the engine, and the black wire to the black wire.

9) Holding the rod, twist the spool of fishing line counterclockwise until it stops. All that remains is to install the two-shoulder belt. Attach the shoulder strap carabiner to the shoulder strap attachment ring. We adjust the position of the ring on the rod of the product and fix it with the fastening screw. Adjust the length of the shoulder strap.

What is the difference between a good trimmer and a bad one?

The main difference: the level of assembly and manufacturability. To do this you need to disassemble the engine. In the figure we see that there is a grid on the engine cylinder mirror. The mirror is finished with final honing. We see a network of small grooves that retain oil, which creates ideal conditions for lubrication of the piston and removal of excess heat.

The cylinder mirror is chrome-plated - this application strengthens the surface layer of the cylinder mirror made of porous chromium, which increases wear resistance and service life, reduces friction and increases the specific power of the engine. Therefore, this particular engine will last a long time even under intense load.

Varieties

The oil that is poured into the engine may differ in the production method. According to this criterion, it happens:

Oil for lawn mowers refers to compositions intended for use in air-cooled engines that have a combustion chamber volume of 50-200 cubic centimeters. In addition, any two-stroke oil may differ from its analogues in additives that give it certain additional characteristics. They come in the following types.

Recently, when purchasing oil for diluting with gasoline, users are very often faced with the fact that special letter abbreviations are applied to the canisters. These designations are made within the framework of the API classification. Let's consider what types of oils exist in accordance with it.

But in addition to this classification, other letter designations of the FA-FD type are often found. It should be said that API is an American standard that is used in Europe. But there is a discrepancy between European smoke emission standards and American ones. For this reason, additional letter designations should be taken into account.

In addition, oils come in two more categories:

In the first case, this will mean that it is necessary to carry out independent mixing, which does not require shaking, and in the second case, this will also need to be done.

How to Correctly Install the Piston on the Trimmer

Replacing the piston group in a chainsaw or trimmer

Repairs of this level must always be balanced. In such small engines operating at high speeds, replacing the first piston, which is burned out or jammed, does not give a long result and, if necessary, you need to change the entire piston group. » How to position it correctly in a chainsaw or trimmer. Making sure the piston sits on. Therefore, you need to consider whether to continue to use this saw or purchase a new saw.

If this is a professional model, then such repairs are worth carrying out, but if it is an ancient household model like the Husqvarna 40 and it has worked for more than 10 or 12 years, it is unprofitable to repair it. Therefore, how much will it cost to repair it? the same as purchasing a new saw, albeit not a Husqvarna, but a PARTNER P350XT CHROME, at a price of 165 will definitely be enough. Moreover, such saws are sold by Husqvarna, since PARTNER is its subsidiary.

But if you still decide to repair a chainsaw or trimmer, then you need unique spare parts that are not cheap. If the engine is used correctly, the first repair may not occur soon and only the piston ring or rings will have to be replaced, depending on the model. But if the saw jams, then you need to change the entire piston group - the cylinder, piston and rings.

You need to see that Husqvarna 136/141 chainsaws have approximately a service life of 500-600 hours, Husqvarna 340/350. 1000-1200 operating hours, professional chainsaws more than 2000-2500 operating hours, subject to strict adherence to the operating instructions. In fact, you cannot rely on these numbers, because the real resource can differ significantly, both hugely and minimally. But approximately we can say that semi-professional saws work 3-4 times longer than amateur saws, and professional ones up to 10 times or more.

Naturally, nothing is endless, but it’s one thing if you change the piston group, after many years of operation and it has worked its hours, it has completely paid for itself, and another thing is that this saw was filled with, for example, only gasoline, without oil, and it jammed. Such a saw has to be repaired, because all other parts are ordinary.

Many companies deliberately inflate the price of spare parts so that new models can be purchased. For chainsaws and trimmers, for example, from the STIHL office, spare parts are available in a larger assortment than for Husqvarna. Therefore, when choosing a specific model, find out how things are with spare parts. RVT

How to correctly install rings on a two-stroke scooter piston

There is nothing complicated about installing rings on the piston of a two-stroke scooter, just like a four-stroke scooter, and many people understand this. But most scooter riders who only recently acquired similar equipment do not even have an idea of ​​how to change the piston on a scooter, how to correctly install the rings on the piston , where the arrow on the piston should point, and almost everything else. In this lesson, I will tell you how to correctly put the rings on the piston and assemble the piston in place. Because we have already talked about four-stroke engines, here we will only talk about two-stroke engines. So, our piston is worn out and requires replacement. Pridonok shows and tells how to correctly install the piston into the cylinder on a scooter and motorcycle. How to install a piston on a lawn mower in this lesson, I will tell you how to correctly put the rings on the piston and assemble the piston in place. The rings wear out first. The rings and piston wear out first, and usually only those need to be replaced. If the piston is severely worn, it is necessary to bore the cylinder. It is also bored when the piston jams in the cylinder, forming deep scratches on the walls of the latter. There is nothing wrong with this, and if your new cylinder has been properly bored (which will only cost about 10), it will need a repair set of rings with a new piston. Such rings are marked 0.25. The second boring is 0.5, respectively, etc. to one. After purchasing a piston, it needs to be assembled. In the kit, as a rule, you will find the piston itself, two compression rings, a third thin corrugated ring (more on its purpose later), a piston pin and two piston pin retaining rings

How to change the piston on a Trimmer.

In this video I will show you how to quickly change the piston on a trimmer yourself. I will change it on the trimmer.

How to install the piston correctly

Pridonok shows and tells how to correctly install a piston into a cylinder on a scooter and motorcycle. Now about the third ring in the kit. Its purpose is to spring the lower compression ring. It installs it directly under it, and usually does not provide any benefit during operation. You can throw this ring away or you can put it in, it makes no difference. How to properly install a piston on a chainsaw. Many piston manufacturers do not include it at all.

It's time to put everything back in place. Depending on the scooter model, compression rings may be the same or vary in thickness and cross-section. Most pistons for Honda scooters, for example, have different rings, where the upper one is thinner than the lower one and has a different cross-section.

You should definitely pay attention to this when installing; the top one is thinner and ground at an angle.

Also pay attention to the inscription on the ring (usually the letter T or repair size); the inscription should always be on top, that is, opposite to the finger. First you need to put on the bottom, then the top. There is no need to stretch or bend them. These manipulations must be carried out carefully.

There are locks in the grooves for the rings that prevent the rings from turning during operation, so the ring gap must be in these locks, otherwise you will not stick the piston into the cylinder.

And the last important point is the arrow (1) on the bottom of the piston or the inscription EX. Both the arrow and the inscription must be directed towards the exhaust (2). In this case, the ring locks will be located on the side of the reed valve. How to properly install a piston on a chainsaw. How right. If the locks are placed towards the exhaust, the piston will not last long, the rings will be pulled into the exhaust port and gradually grind it down.

During all manipulations with the piston, it is imperative to put a rag in the crankcase window so that nothing inadvertently gets in there; we still need a crankshaft with bearings.

When installing the piston pin, pay attention to the condition of the separator (bearing); it may need to be replaced. Before installing the piston pin, install the snap ring on one side before installing the piston (usually on the side where you won't be able to fit the pin and the second snap ring in). Then place the pin with the bearing and the second retaining ring; when fixed in the groove, it will make a certain click.

That's all, now put on the cylinder, not the piston (remembering to check the condition of the gaskets and lubricate the piston and cylinder walls with engine oil), the cylinder head and tighten the bolts one by one in a cross pattern.

MTD-600 trimmer repair advice.

Today I want to share useful information about trimmer repair, which was kindly provided to me by our reader Yuri. With his consent, I am publishing this, in my opinion, very useful information.

READ How to choose a line for a trimmer

I’ll share how I repaired the MTD-600 trimmer (ignition problems), maybe someone will find it useful.

At first, nothing is clear, the trimmer simply won’t start, it won’t even sneeze.

I checked the compression (to exclude damage to the mechanics in the cylinder, rings, connecting rod, etc.) - the compressor shows 10 bar after a couple of jerks - this is quite enough, the cylinder-piston-rings are in order.

Gasoline is supplied through the carburetor - the spark plug is wet and the top of the piston is wet.

The spark plug is clean, the gap is 0.6 mm. When cranking, a spark occurs - we temporarily connect the inverted spark plug (its threaded skirt) with a wire to the cylinder and turn the starter - everything is in order.

There is compression, there is gasoline, there is a spark, but it does not start - this means there are problems with the ignition (ignition timing). But the ignition timing on trimmers/chainsaws and similar two-stroke engines is not adjustable! Therefore, we disassemble the trimmer and remove the engine from the shaft with the starter. The magneto opens - a coil with two terminals-contacts and with two “cheeks” of the core, which at some point are closed by a magnet built into the flywheel to which the starter clings when cranking. It was discovered that this short circuit (it can be seen is the combination of both ends of the magneto core with such well-defined magnet areas in the flywheel, the gap there is a fraction of a millimeter, while in other positions of the flywheel a few millimeters remain above the magneto) does not coincide with the TDC ( top dead center) of the piston (this point is easy to find by turning the shaft, observing the piston into the hole in which the spark plug is turned out).

Here comes the breakdown! The magneto should close somewhere near “top dead center”, but it closes when the piston has gone down somewhere! We unscrew the nut that presses the flywheel to the tapered shaft. It is detected: the pin has been cut off, which fits into the grooves on the outside of the shaft cone and on the inner cone of the flywheel and which rigidly mates them in one position. How to replace and how to properly put fishing line on a trimmer. After this, install the coil. The flywheel "turned". Most likely, someone jerked the starter too stupidly, so he tore off the flywheel, knocking out the ignition (the trimmer is American, it should be easy to start even by a child, no force is needed, but there are tractor drivers with experience in starting a diesel starter, for them this technique will be a bit delicate) .

If there is no standard pin, then you need to make it yourself: a small plate, curved in the shape of a “U”, so that with its “horns” it fits into two grooves in the flywheel, and with its curved part into a wide groove on the conical shaft. How to properly install the reel on the trimmer. How right. Its size is selected experimentally so that the flywheel is lowered on the shaft and securely fixed.

We check the coincidence of the magneto and “TDC” closures, tighten the flywheel nut, assemble the trimmer , and start it according to the instructions.

Many thanks to Yuri for such useful information!

Installing a piston engine (CPG) on a 4t scooter

We take a new piston kit for 72 or 80 cubic meters (piston diameter 47mm or 50mm, respectively). You can, of course, use a standard new 50 cc CPG. The kit includes: cylinder, piston, piston rings, pin, retaining rings, as well as head and cylinder gaskets. You can buy a 72 cc cpg at a low price in our online store.

Installation is carried out in the reverse order, having previously lubricated the cylinder, piston and rings with a small amount of oil. We first install a thin ring on the piston in the lower groove, then an oil scraper ring and again a thin ring (the wavy ring - the oil scraper ring will thus be between the two thin ones in the lower groove). Next, install 2 compression rings, which are thicker). The cuts of all rings should not be located on top of each other. After installing the rings, place the piston on the crankshaft connecting rod, fix its position with a finger and locking rings. We take the connecting sleeves from the old cylinder and insert them into the new one.

We put a gasket under the cylinder on the studs

Carefully place the cylinder on the piston with rings so as not to damage the cylinder. We push the chain into the groove for the chain

Then install the chain bar on the cylinder head. Now we can put the chain on the camshaft sprocket (the position of the sprocket should be as follows: a large hole at the top, and two small ones on the sides, parallel to the edge of the cylinder head). We fix the position of the cylinder head with the gasket by screwing it on. Then we install the plastic cylinder head cover, chain tensioner, carburetor and muffler. The installation is now complete!

If you haven’t changed the oil for a long time, you need to change it before starting with a new piston. Before putting a full load on the scooter engine, it is necessary to run-in, i.e. drive 300-500 kilometers at a speed of no more than 40-45 km per hour.

Along with an increase in the power of the scooter with the installation of a tuning cpg, the load on the variator with the gears of the gearbox also increases. Remember this and if possible, replace the variator with gears with tuned ones (more reinforced.)

How to install a piston into a cylinder on a trimmer

How to install the piston correctly

Pridonok shows and tells how to correctly install the piston into the cylinder on a scooter and motorcycle

Now about the third ring in the set. Its purpose is to spring the lower compression ring. It installs it directly under it, and usually does not provide any benefit during operation. You can throw this ring away or you can put it in, it makes no difference. How to properly install a piston on a chainsaw. Many piston manufacturers do not include it at all.

It's time to put everything back in place. Depending on the scooter model, compression rings may be the same or vary in thickness and cross-section. Most pistons for Honda scooters, for example, have different rings, where the upper one is thinner than the lower one and has a different cross-section.

You should definitely pay attention to this when installing; the top one is thinner and ground at an angle.

Also pay attention to the inscription on the ring (usually the letter T or repair size); the inscription should always be on top, that is, opposite to the finger. First you need to put on the bottom, then the top. There is no need to stretch or bend them. These manipulations must be carried out carefully.

There are locks in the grooves for the rings that prevent the rings from turning during operation, so the ring gap must be in these locks, otherwise you will not stick the piston into the cylinder.

And the last important point is the arrow (1) on the bottom of the piston or the inscription EX. Both the arrow and the inscription must be directed towards the exhaust (2). In this case, the ring locks will be located on the side of the reed valve. How to properly install a piston on a chainsaw.

During all manipulations with the piston, it is imperative to put a rag in the crankcase window so that nothing inadvertently gets in there; we still need a crankshaft with bearings.

When installing the piston pin, pay attention to the condition of the separator (bearing); it may need to be replaced. Before installing the piston pin, install the snap ring on one side before installing the piston (usually on the side where you won't be able to fit the pin and the second snap ring in). Then place the pin with the bearing and the second retaining ring; when fixed in the groove, it will make a certain click.

That's all, now put on the cylinder, not the piston (remembering to check the condition of the gaskets and lubricate the piston and cylinder walls with engine oil), the cylinder head and tighten the bolts one by one in a cross pattern.

How to change the piston on a Trimmer.

In this video I will show you how to quickly change the piston on a trimmer yourself. I will change it on the trimmer.

Installation and removal of piston rings

Can piston rings be installed by hand? What can happen? Why should you always avoid damaging the side surface of the groove when removing oil deposits? You will learn how and in what sequence the piston rings should be installed here.

Piston ring mounting kit Catalog 20 (for passenger cars) Catalog 20 (for trucks)

• Thoroughly clean used pistons to remove any dirt. Pay special attention to ensure that oil deposits and contaminants are removed from the ring grooves. If necessary, also clean the oil drain holes with a drill or other suitable tool.
• When removing oil deposits, be careful not to damage the surfaces of the sides of the ring grooves. The underside of the groove is the sealing surface. Damage to it by scratches can cause increased oil consumption or increased gas breakthrough during engine operation.
• Be sure to use special pliers to install and dismantle piston rings. The use of other aids, such as wire loops or a screwdriver, may damage the piston rings or piston.
• Never install rings by hand (exception: oil control piston rings with steel flaps). In this case, there is not only a risk of breakage, deformation and overstretching of the ring, but also the risk of injury from a broken ring or its sharp edges.

READ How to Cut Grass with a Line Trimmer Video

ATTENTION!

Quick installation of the piston ring by hand, without breaking it, although it confirms the dexterity of the mechanic's hands, often leads to damage to the ring at the time of installation.

• Under no circumstances should the ring be installed on the piston in the manner shown in the illustration. A deformed ring no longer lies flat in the groove, does not rotate in the groove, wears unevenly, and no longer provides a proper seal. However, things get even worse when the molybdenum coated ring experiences peeling or damage to the molybdenum layer. In this case, a violation of the antifriction layer occurs, if not during installation, then during engine operation. The anti-friction coating peels off, damaging the cylinder and piston, on which scuffing appears caused by the breakthrough of hot exhaust gases between the piston and the cylinder wall. Separated fragments of the coating lead to damage to the piston and the working surface of the cylinder.
• Do not remove or install piston rings unless necessary. Each time you remove or install the rings, they become deformed. Do not remove rings from pre-assembled pistons to, for example, check their dimensions.
• Follow the sequence for installing the piston rings: first install the oil control ring, then the second compression ring, and the first compression ring.

Follow the installation markings. "Top" means that this side of the ring should be on top and facing the combustion chamber. If in doubt or if the “Top” marking is missing, install the ring with the mark facing up.

Check whether the rings turn (rotate) freely in the ring grooves.

By successive pressing along the entire circumference, check whether the ring is completely recessed into the annular groove, i.e., in the recessed area, the working surface of the ring should not protrude beyond the edge of the piston skirt. This is important because if there is not enough clearance to the bottom of the groove (due to the use of an incorrect ring or carbon deposits on the bottom of the groove), proper function of the rings is not guaranteed.

When installing 2-piece oil scraper piston rings, always ensure the correct position of the spring expanders. The ends of the spring expander should always be located on the opposite side of the piston ring lock.

How to properly install a piston on the crankshaft of a lawn mower or chainsaw

For rings consisting of 3 parts, maintaining the correct position of the expansion spring is a prerequisite for ensuring the oil removal function. Even if a piston with pre-mounted rings is installed in the cylinder, be sure to check the correct position of the expansion spring. During transportation of such pistons, the ends of the spring are in a relaxed state, which is why they may overlap each other. Both color markings on the ends of the spring should be visible. If any of them are not visible, then the ends of the spring are overlapped and the ring will not function. All locks of the 3-part oil control piston ring (both steel plates and the expansion spring) must be installed at an angle of 120° relative to each other.

Replacing the piston group in a chainsaw or trimmer

Repairs of this level must always be balanced. In such small engines operating at high speeds, replacing the first piston, which is burned out or jammed, does not give a long result and, if necessary, you need to change the entire piston group. » How to position it in a chainsaw or trimmer. Making sure the piston sits on. Therefore, you need to consider whether to continue to use this saw or purchase a new saw.

If this is a professional model, then such repairs are worth carrying out, but if it is an ancient household model like the Husqvarna 40 and it has worked for more than 10 or 12 years, it is unprofitable to repair it. Therefore, how much will it cost to repair it? the same as purchasing a new saw, albeit not a Husqvarna, but a PARTNER P350XT CHROME, at a price of 165 will definitely be enough. Moreover, such saws are sold by Husqvarna, since PARTNER is its subsidiary.

But if you still decide to repair a chainsaw or trimmer , then you need unique spare parts that are not cheap. If the engine is used correctly, the first repair may not occur soon and only the piston ring or rings will have to be replaced, depending on the model. But if the saw jams, then you need to change the entire piston group - the cylinder, piston and rings.

You need to see that Husqvarna 136/141 chainsaws have approximately a service life of 500-600 hours, Husqvarna 340/350. 1000-1200 operating hours, professional chainsaws more than 2000-2500 operating hours, subject to strict adherence to the operating instructions. In fact, you cannot rely on these numbers, because the real resource can differ significantly, both hugely and minimally.

Naturally, nothing is endless, but it’s one thing if you change the piston group, after many years of operation and it has worked its hours, it has completely paid for itself, and another thing is that this saw was filled with, for example, only gasoline, without oil, and it jammed. Such a saw has to be repaired, because all other parts are ordinary.

Many companies deliberately inflate the price of spare parts so that new models can be purchased. For chainsaws and trimmers, for example, from the STIHL office, spare parts are available in a larger assortment than for Husqvarna. Therefore, when choosing a specific model, find out how things are with spare parts. RVT

How to correctly install rings on a two-stroke scooter piston

There is nothing complicated about installing rings on the piston of a two-stroke scooter, just like a four-stroke scooter, and many people understand this. But most scooter riders who only recently acquired similar equipment do not even have an idea of ​​how to change the piston on a scooter, how to correctly install the rings on the piston, where the arrow should point , and almost everything else.

READ Gasoline trimmer oil/gasoline ratio

In this lesson, I will tell you how to correctly put the rings on the piston and assemble the piston in place. Because we have already talked about four-stroke engines, here we will only talk about two-stroke engines. So, our piston is worn out and requires replacement.

Pridonok shows and tells how to correctly install the piston into the cylinder on a scooter and motorcycle. How to install a piston on a lawn mower in this lesson, I will tell you how to correctly put the rings on the piston and assemble the piston in place. The rings wear out first.

The rings and piston wear out first, and usually only those need to be replaced. If the piston is severely worn, it is necessary to bore the cylinder. It is also bored when the piston jams in the cylinder, forming deep scratches on the walls of the latter.

There is nothing wrong with this, and if your new cylinder has been properly bored (which will only cost about 10), it will need a repair set of rings with a new piston. Such rings are marked 0.25. The second boring is 0.5, respectively, etc. to one.

Usage

If the piston is powered by a red stone signal, its wooden head will extend, which will try to push out the blocks in front (if they are movable and there are no more than 12 of them). The extension lasts about one and a half redstone ticks (0.15 seconds) and is accompanied by a sound that can be heard at a distance of 15 blocks from the piston along any axis. At the same time, if there are entities on the way, then if there are no blocks on their way, they will also be moved (and if the block being moved is a block of mucus, then the entities will be discarded), otherwise the head or block will pass through them; in the case of a block, entities can be smothered by the block if it is solid.

When the piston is turned off, the head will extend back. Moreover, if it is a sticky piston, then the head will try to move the block “glued” to it with it. The sticking effect only occurs when the head is moved, so falling blocks will still fall after moving if there is free space underneath them; also, a block that was moved by a sticky piston can be moved by another piston without any complications. In addition, if the sticky piston loses power before

Before he manages to
out
, the piston “unsticks” from the block, which remains in its new place.
If such a piston did not push anything out and the power is still turned off prematurely, then the block that was destined to be pulled along with it will be moved as usual (though somewhat faster).

Installing a piston on a Chinese lawn mower

The piston head, when installed, points in the direction of the player who installed it.

Progress:

First you need to make the base of the nozzle. To do this, use a grinder to cut out a square with a side of 100 mm from a metal plate. You need to mark it in such a way that there is a hole exactly in the center (at the intersection of the diagonals). To do this, from the center of the selected hole perpendicular to the short side of the plate, measure a distance of 50 mm and mark the trimming line.

We cut off the excess and get a square of 100 mm x 100 mm. Now you need to slightly round the corners and drill out the central hole for the trimmer shaft.

Round the corners and drill the central hole for the trimmer shaft

We cut the metal sheets, measuring 8 cm from each end. We get 4 blanks with ready-made holes.

These blanks must be shaped into knives. To do this, we mark the cutting line by eye (special precision is not required), fasten all 4 blanks together and grind off the excess.

As a result, we get knives of the same weight and size; they can be sharpened a little on one side. Now all the parts of the homemade trimmer attachment are prepared, you can start assembling.

We put a small washer on the screw and insert it into the corner hole. We put the knife on top, placing the sharpened side in the direction of rotation of the trimmer shaft. Next comes a large washer and a nut, which is not tightened so that the knife rotates freely. We attach the other 3 knives in the same way.

The end of the screw must be riveted so that the nut does not fly off.

The nozzle is ready. It is installed with nuts to the ground and secured in the same way as the three-bladed knife that comes with the trimmer. When colliding with a stone, the knives fold and go inward a little.

This idea was proposed by our regular video author Tatyana (Tula region). You can see in more detail the entire process of making such a trimmer attachment and learn some of the nuances by watching the video she prepared.

When working with a trimmer, it is important not to forget about safety precautions when using any attachments, especially homemade ones.

Where to place the piston arrow on 2- and 4-stroke engines | Pin offset (Desaxial) | Dnepr/Ural.

We invite you to discuss this idea in the comments to the publication. Share your thoughts with us and also tell us about your successful decisions.

Without taking either side of this heated (literally and figuratively) debate, let me show you one of the latest models of lawn mowers from the German company Robert Bosch. It has both a deflecting knife and an arc-shaped bracket, which prevents the knife from “striking” against objects not intended for mowing. I show a general view of the brush cutter and the knife itself, in two positions. General view of the brush cutter

Good evening everyone! Exactly three years have passed since the discussion of the “acute” problem for the trimmer. Over the past 1000 days, a clear picture has emerged: “Glory to the author - the craftsman who is conducting an experiment on himself to achieve the yield point of the metal from which these knives are made.

He has every right to risk his own health.” Nowadays, in stunt films you can often see the phrase - “Don’t try to repeat movie stunts that were performed by professional stuntmen.” The very first article should have ended with approximately the same phrase:

» Dear summer residents. This is my personal experiment. If you are not confident in your locksmith skills, please do not repeat it. AND THE MOST IMPORTANT THING - I am not responsible for the operation of the tool made in the wake of my article.” And one last thing. Do I see errors, judging by the photographs, of the implementation of this tool.

Alas, the author of this device does not even know how the hole for the shaft should be made.

I inform you that the distance from the point of the hole closest to the edge of the plate to the very edge should be NO LESS than the diameter of the hole itself. Mechanical engineering students will learn this truth no later than their second year at the institute. What do we see here? A thin isthmus reminiscent of a narrow PEREKOP, making a peninsula out of Crimea.

This is a priori the place that is weak in this design - it experiences the same loads as other knives, and the “dig” there is very thin. Where it is thin, there it is... I would like to hope, and quite sincerely, that over these three years this isthmus has not undergone loads comparable to the yield strength of this metal, but rather the alloy from which the perforated plate is stamped.

Why do engine parts break?

Breakdowns can be planned or emergency. Planned failure depends on the manufacturer, the materials used to manufacture the group, and the intensity of use. Usually the life of a saw is calculated in engine hours. After working out the required number of engine hours, you should submit the tool for repair for engine maintenance.

Causes of unexpected piston failures:

• operation under increased loads incomparable with the power of the tool;
• lack of normal maintenance, which leads to dry engine operation and increased wear;
• the use of low-quality fuel, which does not provide stable engine operation;
• the saw is very old, despite the low intensity of use.

Each start of the tool is a certain stress for the piston and cylinder. Therefore, the life of the device also depends on the number of starts. If you notice extraneous sounds from the engine, a decrease in power, or an increase in consumption, it’s time to take the equipment to a service center for preventative repairs.

What is a piston in an internal combustion engine

A piston is an element of a piston internal combustion engine designed to convert the energy of changes in the pressure of compressed gas in the cylinder into the energy of translational motion. Next, the energy is converted into rotational motion using the crankshaft and connecting rods.

When disassembling the chainsaw engine, be sure to remember or mark how you removed the pistons from the cylinders. Important information is usually indicated on the surface of the piston ring heads, which can be seen by removing soot deposits.

Setting the valve timing ch2 (in collective farm style - ignition)

Without knocking the piston off from TDC, we orient the camshaft so that the large hole and marks on its sprocket become as shown in the photo and, while putting on the chain, install the camshaft in bed.

Ideally, the marks on the sprocket should be strictly parallel to the plane of the valve cover connector. In practice, unfortunately, such accuracy is difficult to achieve. And this is mainly due to the stretching of the timing chain. And there’s nothing you can do about it - either change the timing chain to a new one or catch the phase by switching the teeth, but this method of setting the valve timing is not acceptable to me personally.

We orient the camshaft bed with a mark in the form of the letters “E” and “X” towards the exhaust channel and install the bed.

Tighten the bed nuts crosswise and then tighten the two bolts on the side boss of the cylinder head.

Where does the arrow on the chainsaw piston point?

The heart of any chainsaw is the internal combustion engine, which drives the working element - the sawing chain. During the operation of a garden tool, it becomes necessary to disassemble the engine. This could be scheduled maintenance, cleaning from carbon deposits and soot, troubleshooting or replacing components. If you take the chainsaw to a service center for this, then you will not have any questions. However, when independently servicing a gasoline engine of a garden tool, the question often arises: how to correctly install the pistons back and where the arrow points to them.

Fault detection algorithm

The cause of saw failure or deterioration in its performance may be:

• clogged fuel tank cap breather;
• air leakage from the carburetor due to the destruction of the gasket or loosening of the threaded fasteners;
• mechanical jamming of removable saw equipment and other minor defects.

Before you begin disassembly, you should make sure that more extensive repairs are necessary.

It will most likely not be possible to independently assemble a new chainsaw after repair with the original quality. The design of modern chainsaws often uses press fits of mating parts, which have minimal repairability.

Even partial disassembly of a chainsaw using improvised tools can lead to undesirable consequences. In most cases, to eliminate a malfunction, you can limit yourself to dismantling a separate unit or system.

This list includes:

• connecting rod and piston group;
• carburetor;
• clutch mechanism;
• saw chain drive sprocket.

Where does the arrow on the piston point?

Due to the fact that the pistons have the correct cylindrical shape, after removal, many inexperienced craftsmen are confused about how to properly return them to their place.

• Remember the main rule: the arrow on the chainsaw piston points in the direction of the exhaust towards the exhaust hole of the cylinder.

Installing a piston on a Chinese lawn mower

The pistons in the cylinders in modern internal combustion engines have a very strict position, so the arrow always points in the direction where the exhaust gases move. If you still have questions, the garden tool has an instruction manual. Even if it is in English, it will not be difficult to translate it.

Receipt

The pistons can be removed with any tool (even by hand), and in any case it will drop out as a pick-up item.

Piston power

Pistons can be powered in various ways:

• If the red wire is directed directly to the piston, and directly behind it it has the shape of a straight mowing line. The wire does not automatically bend towards the piston.
• If right next to him there is a block charged with a red stone (of any strength) or a red torch.
• If the charged block is located diagonally above the piston, or two blocks above it. There is no physical contact with the piston, so the piston “does not realize” that it is charged until it is updated by the neighboring block (the phenomenon of quasi-connectivity). Many block update sensors are built on this principle.
• The pistons are considered a non-solid (“transparent”) block, so it is impossible to transfer energy through them.
• Pistons cannot be charged from their head side. However, if the piston is directed upward and pushes a charged block there, then due to quasi-connectivity (see above) it will be charged with it.

What can result from incorrect piston installation?

Incorrect installation of the piston ring in the chainsaw engine will lead to the fact that it will work strained and intermittently, and may stall. Eventually, at best, the piston or cylinder will be damaged. In the worst case, the engine itself will fail and require expensive repairs.

If your chainsaw needs repair or maintenance, take it immediately to a specialized service center. It is better to pay a specialist than to buy new garden tools.

Sources:

https://jusof.com/kak-pravilno-stavit-porshen-na-trimmere/ https://vseopilah.ru/trimmery/kak-ustanovit-porshen-v-tsilindr-na-trimmer/ https://navro. org/kuda-ukazyvaet-strelka-na-porshne-benzopily/

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Result

We investigated the main causes and malfunctions of the Stihl ms 180 chainsaw that require CPG replacement. But, as a rule, in each case the reasons may overlap, and proper repair requires an integrated approach to solving the problem. Installing a new piston on the pole does not always solve the problem. Be sure to eliminate the cause of the malfunction, and the tool will last a long time without problems or the need for repair.

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independent chainsaw repair

possible if you follow the instructions

A private homeowner must have a chainsaw on his property. An indispensable thing in the household if you need to chop firewood, trim dry branches on garden trees, or even a whole tree.

Related Posts

In recent years, Stihl has been a market leader in garden technology. Chainsaw companies have an affordable price in the region of 7000-8000 rubles and high quality at this price. That's why they were welcomed not only by private sector residents, but also by loggers and utility companies to improve land. Unfortunately, even high-quality equipment develops over time and requires replacement of individual components. You often have to do chainsaw repairs yourself, since breakdowns usually begin after the warranty period.

Source

Clutch

At low speeds, elements with friction linings (1), having a degree of freedom in the circular direction, are attracted to the center of the shaft by springs (2) and do not transmit rotation to the drum (3), connected to the sprocket driving the chain. Where is it located in the chainsaw? The tank has a breather depressurization valve (Husqvarna).

Where is the breather located in a chainsaw? Construction, repairs with your own where the breather is located. When the chainsaw engine speed reaches values ​​at which the centrifugal force exceeds the force of the springs, the friction segments are pressed against the inner surface of the drum and begin to rotate it. As a result, the drive sprocket begins to rotate, driving the saw chain.

As you can see in the photo, the sprocket is located behind the clutch.

On other chainsaws, the sprocket may be located on the outside of the clutch.

The main advantage of this type of coupling is that when the chain jams, the chainsaw clutch slips without stopping the engine or causing damage to the devices that transmit movement from the motor to the chain.