How to Put a Piston On a Trimmer

One of the most important parts of any chainsaw is the cylinder-piston group (CPG), which transmits rotational motion to the drive sprocket. Despite the reliability of this unit, most models require diagnostics and repairs over time. It is the performance of the CPG of the chainsaw that determines the power of the unit, its ease of starting, the presence of idling and the consumption of the fuel mixture.

Causes of Piston Chainsaw Problems

There are many reasons for the failure of the CPG, which can be divided into two main categories: natural wear and tear. The first type of malfunction, as the name implies, is the physical wear of the rubbing parts of the piston group. The second category is more extensive and implies:

Elements of a piston chainsaw

  • Severe overheating of the internal combustion engine and, as a result, the appearance of thermal seizures on the piston surface;
  • Breakdown of the lower part of the piston (skirt) due to the duration of the chainsaw at maximum speed;
  • Ingress of foreign particles into the combustion chamber and the occurrence of mechanical damage to the CPG;
  • Breakdown of the compression (piston) ring due to severe wear or exceeding the permissible revolutions of the saw;
  • Mismatch of the recommended servings of gasoline and oil when preparing the fuel mixture.

Worn Chainsaw Piston

Experts do not recommend disassembling the CPG without any special reason. However, if the tool has significantly lost power, a metallic ringing has occurred in the internal combustion engine or the crankshaft does not crank when the starter jerks, a piston chainsaw should be diagnosed. First of all, to identify engine problems, it is necessary to measure the compression in the cylinder. With a significant deviation from the values ​​recommended by the manufacturer, we can safely say that there are scratches, working out, and scuffing on the surface of the cylinder or piston. It is the drop in compression that is the basis for the complete disassembly and repair of the piston group of the chainsaw.

Chainsaw Piston Group

The dimensions of the cylinder-piston group are determined primarily by the diameter of the piston made of heat-resistant aluminum alloy. Regardless of the model, the CPG of a chainsaw consists of a cylinder, a piston, a holding finger and two clamps.

Chainsaw Cylinder Mirror

In order to increase compression in the working unit and, as a result, increase power, many manufacturers install two piston rings. The compression rings of the chainsaw made of special cast iron fit snugly against the cylinder, as a result of which the tightness of the combustion chamber is ensured.

Piston Chainsaw Replacement Algorithm

If it is time to replace the CPG of the chainsaw, you need to know that for each specific model there is an individual algorithm of actions. To facilitate disassembly / assembly, it is necessary to prepare a candle wrench, a large flat screwdriver, a hammer, a compressor for cleaning the parts of the unit, a set of open-end and end wrenches. Regardless of the manufacturer and design features of the model, before removing the chainsaw cylinder, the following work must be done:

  1. Dismantling the upper protective cover;
  2. Unscrewing the spark plug;
  3. Side cover removal;
  4. Using a large flat screwdriver, the stoppers are removed from the shock absorbers;
  5. In the channel of the candle we put a lace to fix the crankshaft and unscrew the clutch and the flywheel nut;
  6. Dismantling the drive chain sprocket;
  7. We remove the carburetor with an air filter;
  8. Remove the ignition module and exhaust system.

After removing from the base of the power unit, unscrew the pan and remove the crankshaft with the piston from the cylinder. Using a pair of tweezers or a screwdriver, remove the piston pin stops.

Sealant for fixing the chainsaw chainsaw

Before starting assembly, it is necessary to clean the parts and components of the unit from dirt, sawdust residues, dust with compressed air, rags and other means. The first step in replacing a piston chainsaw is to install a piston on the crankshaft. We fix it on the connecting rod with a steel finger, which is supplied with the CPG. In order to prevent arbitrary loss of the retaining rings, it is recommended to install them cut down. Next, we mount the compression rings on the piston, but due to their fragility and fragility, this operation must be approached as carefully as possible. To prevent scratches, the piston must be lubricated with oil before installing the piston in the cylinder. Before installing the crankcase (pan), you will need to degrease its mounting surface and apply a layer of heat-resistant sealant. We assemble the chainsaw in the reverse of the algorithm described above.

Often replacing the piston of a chainsaw, crankshaft and compression rings solves the problems with idling and the problematic start of the engine.

Home »How to Install a Piston On a Chainsaw Properly

Related posts

How to put the piston on a chainsaw

BenzoInstrument – LIKBEZ

Blog Search (loose match):

Documents matching your request: 9 [shown 5]

All my attempts to find out what kind of model it is and in what years it was produced ended up to no avail (I will be VERY grateful to you if you will help me in any way in this matter). But I can approximately imagine that this is in some places the 60-70s of the last century. If you do not exchange the chainsaw 1. If the piston in the cylinder is not how to dilute gasoline. The chainsaw used CONTACT ignition from the company BOSCH.

The number – 21554 is knocked out on the crankcase. The importance of correctly installing the saw chain on the chainsaw. How to install the circuit. What kind of room is it all? For me, a riddle

There is a nameplate on the left side of the saw.

What kind of information is indicated on it for me as well – black forest :-))).

I partially dismantled the chainsaw (for cleaning and assessing the condition of parts). I also replaced the tip of the spark plug (all was cracked) and set the ignition switch (not present at the time of purchase of the saw). How to properly install the rings on the piston of a two-stroke scooter published on 25.08 | author: scooter.Rv.Ua in installing rings on the piston of a two-stroke scooter, however, like a four-stroke, there is nothing. These details, as you realize, are not unique :-))). And another minus is the lack of an oil tank cap. (Everything is indicated by arrows in the photo).

Carburetor air damper drive

There is a chain on the saw – TAKASAGO (I have never heard of such, but this is indicated by the inscription on the cutting tooth).

The length of the tire is 620 mm.

Chainsaw DOLMAR. About three or four months ago, this instance was in my hands chainsaws Dolmar.

Dismantling – assembly of the STIHL MS180 chainsaw. The degree of compliance with the request: 21.43%
Fragments of the text of the post. Dismantling – assembly chainsaws STIHL MS180. Disassembly chainsaws STIHL MS180. Assembly chainsaws STIHL MS180.

Video: How to Put a Piston On a Trimmer

Chainsaw PARTNER 352.

Replacing the piston group in a chainsaw or trimmer

Repair at this level should always be balanced. In such small engines operating at high revs, replacing one piston that is burnt or stuck does not give a long result and, if necessary, the entire piston group must be changed. Therefore, you need to consider whether to use this saw further or to purchase a new saw.

If this is a professional model, then such repairs should be carried out, but if it is an old household model such as Husqvarna 40 and it has worked for more than ten or twelve years, it is not profitable to repair it. Because its repair will cost, as much as the purchase of a new saw, let not Husqvarna, but on PARTNER P350XT CHROME, worth 165 is definitely enough. Moreover, the company Husqvarna sells such saws, because PARTNER is its subsidiary.

But if you still decide to repair a chainsaw or trimmer, then you need original spare parts that are not cheap. With proper operation of the engine, the first repair may not occur soon and only the piston ring or rings will have to be replaced, depending on the model. The answer to a popular question about the launch of a chainsaw. On the Internet, you can often find questions about how you can start a chainsaw without the help of a starter. But if the saw is jammed, then it is necessary to change the entire piston group – the cylinder, piston and rings.

It should be noted that Husqvarna 136/141 chainsaws have approximately a resource of 500-600 hours, Husqvarna 340/350 – 1000-1200 hours, professional chainsaws at least 2000-2500 hours, subject to strict observance of the operating instructions. In fact, it is impossible to rely on these figures, since the real resource can significantly differ both up and down. But it can be roughly said that semi-professional saws work 3-4 times longer than amateur ones, and professional ones up to 10 times or more.


The video discusses a detailed replacement of the piston group chainsaws, How to do it correctly, in stages and without.

Replacing the piston on a DOLMAR chainsaw

Under repair chainsaw Dolmar 116. Piston installation. ?Writing off gasoline, please tell me how to write off gasoline on a lawn mower and chainsaw, if there is no exact calculation, then the norm must be established experimentally by the fact and act. Find out more on our website: Subscribe.

Of course, nothing lasts forever, but it’s one thing if you change the piston group, after many years of operation and after working its hours, it completely pays for itself, and it’s another thing that for example this saw was refueled with one gasoline, without oil, and it got stuck. Such a saw has to be repaired, since all other parts are normal.

Many companies specifically overcharge the cost of spare parts to buy new models. For chainsaws and trimmers, for example, the company Stihl, spare parts are available in a larger assortment than on the Husqvarna. Therefore, choosing a particular model, find out how things are with spare parts.

How to install rings on the piston of a push-pull scooter

Posted on 08/25 | Author: scooter.Rv.Ua

In installing rings on the piston of a two-stroke scooter, however, as well as a four-stroke, there is nothing complicated, and many know this. But most scooters who only recently acquired a similar technique do not even have an idea about how to replace the piston on the scooter, how to correctly install the rings on the piston, where the arrow on the piston should look, and much more. In this lesson, I will tell you how to properly put the rings on the piston and assemble the piston into place. Since we already talked about four-stroke engines before, we will only talk about two-stroke engines. So, our piston has worn out and needs to be replaced.

First of all, the rings and piston wear out, and usually you only need to change them. With severe piston wear, it is necessary to bore the cylinder. It also opens up when the piston wedges in the cylinder, forming deep scratches on the walls of the latter. There is nothing wrong with that, and if your new cylinder has passed the correct bore (for which you will need to lay out only about 10), it will need a repair kit of rings with a new piston. Such rings are marked with a 0.25 mark. The second bore, respectively, 0.5, etc. Up to one.

After buying a piston, you need to assemble it. In the kit, as a rule, you will find the piston itself, two compression rings, a third thin corrugated ring (about its purpose later), a piston pin and two piston pin retaining rings.

Now about the third ring in the kit. Its purpose is to spring-tighten the lower compression ring. It installs under it itself, and usually does not bear any benefit during operation. Use the saw stop as you put on the chain so that the chain is properly tensioned. You can throw out this ring, or you can put, there is no difference. Many piston manufacturers do not have it at all.

It’s time to put everything in place. Depending on the scooter model, the 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 top is thinner than the bottom and has a different cross section.

It is necessary to pay attention to this when installing, the upper one is thinner and sharpened at an angle.

Also pay attention to the inscription on the ring (usually the letter T or the repair size), the inscription should always be on top, that is, the opposite of the finger. First you need to wear the bottom, then the top. You do not need to stretch and bend them. These manipulations must be carried out carefully.

In the grooves for the rings there are locks that prevent the rings from turning during operation, so the gap of the rings should be in these locks, otherwise you will not stick the piston into the cylinder.

And the last important point is the arrow (1) at the bottom of the piston or the inscription EX. And 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 flap valve. How to choose a chainsaw (chain, whether the tire should be pressed on the chainsaw when sawing. If you put the locks in the direction of the exhaust, the piston will not last long, the rings will be pulled into the exhaust window and gradually grind it off.

When installing the piston pin, pay attention to the condition of the cage (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 it will be inconvenient for you to pry the finger and the second snap ring). Then put the finger with the bearing and the second snap ring, when locked in the groove it will give a definite click.

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

If you have any questions during the piston replacement process, you can ask them in the comments box or on the forum of our site. How to install the piston on the lawn mowing. How. Good luck in the repair.

Installing the chain on the chainsaw, how to properly tension and check the tension

If you have a chainsaw at home, then you should know that it requires special care. It is necessary to clean and sharpen the chains from time to time, to clean the air filter, oil supply and tires. Well, of course, you need to look at the stretch of the chain, because with a bad stretch, there is a risk not only to harm the saw, but also to your own health if the chains fly off at high speeds.

Features of the chainsaw device

The main part of a gasoline saw is engine. In most modern devices, the engine is single-cylinder. Air cooling, two-stroke piston system. Oil in these types of engines is added directly to gasoline, and all due to the fact that the fuel is constantly washing the crankcase. The oil-gasoline ratio varies from 1:20 to 1:50, depending on the manufacturer of the chainsaw.

How to Put a Piston On a Trimmer

An air filter on gasoline saws plays an equally important role. He needs regular cleaning. If you allow severe contamination of the filter, then the dust from it will fall directly into the piston system, which will lead to engine failure.

If the filter is clogged, the saw loses speed, and the engine starts to overheat, and this can lead to burning of the piston rings.

A gasoline-powered starter is a rope with a handle, pulling which you drive the motor. When you pull the rope, the teeth catch the ratchet, the flywheel begins to unwind.

Many complain that it takes a long time to pull the rope to ignite the engine. It depends on whether the carburetor is correctly set. If the carburetor produces the correct oil-gasoline mixture, then no problems should arise.

The main working mechanism – a tire with a chain.

The chain consists of three types of teeth: leading, cutting and connecting. They are connected by rivets. The cutting teeth are located on two sides: right and left.

Chains are divided into two types: high-profile and low-profile. The first type includes chains, in which the teeth are located with a large gap, the second – with a smaller gap. Also, chains may vary in shank thickness and link length. The chainsaw chain is attached to the tire, which directs it in the right direction. The end face of the tire has a specific groove that holds the links and allows the chain to rotate. At the front of the tire is a driven sprocket. The chains along with the tire are called the headset, as they are removable parts of the chainsaw.

The gasoline saw has an automatic chain lubrication system. The tire delivers oil, which is then absorbed by the sawdust. If the saw is idling, the oil supply is cut off.