How to break in a new chain saw

How to run in the engine after repairing it

Internal combustion engines after a complete overhaul need running in. The difference in the process of lapping between a new engine and after the overhaul only in the fact that less running-in hours are required (1 tank is enough). Otherwise, all steps are performed similar to the process of running in of a new tool.

After a complete overhaul of the engine, it is also desirable to fit a new tire, chain and sprocket. This allows you to run in the entire set at the same time. Fill the fuel tank with a mix of gasoline and oil. It is necessary to choose gasoline of АI-92 brand, but not lower, and special oil for a mixture with fuel is chosen for two-stroke engines.

How to properly run-in a chainsaw?

The running-in process for a chainsaw is very important. it depends on the quality of the running-in of the key parts of the chainsaw engine, as well as the further work of the tool in various conditions.

break, chain

To properly run-in a new chainsaw, the owner needs to remember a few important points:

  • The running-in period is not the same for saws from different manufacturers;
  • Different chainsaws have different engine brands and fuel percentages, which means they require different running-in procedures;
  • it is important to establish, on what stroke of the chainsaw the running-in is performed. cyclic or idle (this information is necessarily indicated in the instruction, which must be read before starting to work with a chainsaw).

As an example, take a Husqvarna chainsaw. its running-in is always done only in cyclic rotation! Thus the engine should work at high revolutions, but with small capacity.

Remember that breaking the running-in conditions, you run the risk not to receive warranty repair in case of breakage.

How to run in a two-stroke engine properly?

Having purchased a new chain saw (grass trimmer, power drill, generator) with a two-stroke engine many people have a desire to run in.

In the understanding of most “running-in” is made to run in the engine parts at idle speed. So this is such a running-in to modern two-stroke air-cooled engines do not need. over, it is contraindicated!

Breaking in a new chainsaw & Husqvarna 592xp ship date!

The two-stroke engine works on a mix of fuel: gasoline, oil and air. When reaching operating speed (at full throttle, with the choke open), the oil in the cylinder burns off completely without settling on the surfaces of the cylinder, piston, muffler. If the engine does not reach operating speed, unburned oil is accumulating. You can even see oil starting to leak out of the muffler And with prolonged idling, as happens with “running-in”, there is little air coming in, no oil burning, no cooling of the engine. Excessive amount of oil in the air/fuel mixture (at idle speed little air is fed into the mixture, the mixture is “enriched”) leads to coking of the exhaust window and formation of carbon deposits on the piston.

Our Service Center occasionally receives grass mowers (chain saws) after such a running-in period. The degree of difficulty is different for everyone: some people get scared when they see oil leaking from the muffler and stop the running-in period. In this case, the owner of a new Grasshopper or a new Saw will get off with a minor scare))) The worst thing is when the new owner of a two-stroke engine makes running-in on several tanks of fuel (2-3), in summer when the air temperature is from 25C. There are consequences such as in the photo above. It is good if this soot has not chipped off and the cylinder and piston group has not been scuffed But it also happens.

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It should be noted that for a two-stroke alternator engine operation for lighting one light bulb is tantamount to idling. So prolonged use of an alternator in this manner leads to the consequences described above. It is not recommended to give the two-stroke generator a load of less than 30% of nominal output.


It is also worth remembering that when the engine of a chainsaw, mower or power tiller is running, the crankshaft on which the clutch is mounted rotates. When working at idle centrifugal force is not enough to meshing with the clutch cup, but the clutch cams are still a bit divergent and their friction occurs, and thus heating. On a chainsaw it is possible that the worm wheel (which is on the clutch cover), oil pump, chain brake cover, overheating of the clutch, overheating of the clutch cover) may melt. The grass trimmer can melt the body of the clutch cup. if it is plastic, overheat the clutch cup and the clutch.

And the new owners of a new mower are really surprised that such problems could arise, because they seemed to have done everything right.

Other owners may assure you: “here I have run in. and everything is fine”. You can of course believe them It’s your right. And you can even run it in this way yourself.

But a correct “running-in” of a modern two-stroke engine is a little different:

The engine run-in is the time when all the running-in parts are lapped.

Do NOT run in at idle speed.

Running-in time (lapping parts) is the time it takes you to burn 1-2 fuel tanks of your tool.

It is recommended that the fuel mixture be mixed with a little more oil during the running-in period. If you usually use a mixture (recommended by the manufacturer, indicated on the oil bottle) of 1:50, then during the running-in, prepare a mixture of 1:40.

And most importantly! To work (Attention. Exactly work. ) with the tool without overloading the engine! If it is a saw, do not cut wood that is more than a third of the length of the guide bar. If it is a mower, mow using a trimmer head with a line of the recommended size. Do not mow tall grass, not waist-high bushes. If it is an alternator, do not overload it.

It is recommended to shorten the running-in period without interruption and let the engine cool down.

After such a run-in is recommended to check all threaded connections, tighten everything that is loose.

And importantly! If you have a suspicion that your new engine is working incorrectly, the carburetor does not develop speeds or something like that: in no case do not try to adjust the carburetor yourself. Unauthorized attempts of self-repair may cause the tool to be disqualified from warranty service. Contact an Authorized Service Center.

A chainsaw is made up of a number of parts that, during intensive work, become hot and subject to increased friction. As a result of increased stresses, most garden tool parts are subjected to severe wear and tear. Most often it leads to minor failures, but it is not uncommon to see deformation of the drive sprocket, burr formation on the surface of the cylinder-piston group and other serious breakdowns.

To avoid these malfunctions and to get your chainsaw working properly, you need to run it in and out after you buy it. This is where the moving parts move in the direction the machine is designed to move. In addition, running-in a new chainsaw allows the lubricating fluids used to evenly distribute throughout the structure of the tool and cover the parts of the saw with a thin film of oil. In the future, it will protect the mechanisms of the chainsaw from high temperatures, increased friction, corrosion and fouling.

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Running in of the Chinese chainsaw. the procedure

The main difference between most chainsaws from China and European and American brands is the high power. Because of this, Chinese garden tools need a longer run-in period.

Before starting to prepare a Chinese chainsaw, its owner must make sure that the carburetor is set correctly. If the adjustment has not been made by the manufacturer, the settings will need to be adjusted. over, experienced users do not recommend that beginners do the first adjustment of the carburetor on their own. It is best to take the saw to a service center whose staff specializes in the maintenance and repair of chainsaws from China.

Further running-in of the Chinese garden tool is carried out in this sequence:

  • First you fill up the machine with fuel mixture and oil for chain lubrication. It is necessary to remember about the principles of fuel preparation. Chinese saws need more engine oil than the European ones;
  • After that you should start the engine and leave it running at idle rpm until the first tank of fuel is used up. At the same time it is necessary to start the engine every minute;
  • Then you need to refuel the chainsaw and start cutting small, dry branches. It is necessary to work with wood with minimum load on the engine of the tool and to stop the engine to cool down every 15 minutes;
  • As soon as the second fuel tank is used up, you need to add a fresh fuel mixture and start cutting medium thickness wood. Saw small branches and logs until the third tank of fuel is used up;
  • Then wait until the engine has cooled down completely and refuel the chain saw to cut very thick logs.
break, chain

The main requirement during the running-in period of a new Chinese chainsaw is to take breaks when the plastic body of the tool heats up to a critical state. This indicates extreme crankshaft rotation speed, which can lead to failure of its fixation and breakdown of the engine cylinder block.

How to correctly run in new machines. step by step instructions

After all the preparatory steps have been taken, the actual running-in is begun. Procedure:

  • Disengage the cutting tool brake (push its handle forward until it touches the front handle). This is a mandatory procedure, otherwise severe heat will occur in the clutch area, which can lead to melting of the body and failure of the tool parts. Check the condition of the chain by pulling it in the direction of movement. Gloves should be worn on your hands.
  • Close the choke and turn on the ignition. If there is a decompression valve, turn it on.
  • Take hold of the starter grip, pull it a little taut until there is a firm contact and pull it violently several times until there is a burst of fuel in the combustion chamber. The machine should start and then stop after a second or two. Then open the choke and restart the engine.
  • After starting the engine start with a full throttle and let the machine idle for 3-5 min. Read more about how to start the chain saw.
  • Saw small trunks or branches not more than 10 cm thick. The load is dosed. firstly a small, then medium, and the transition to the maximum working load is made at the end of the running-in (after 5-6 full fuel tanks).
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Important! there is often advice on the web about running-in at idling speed. Grief-experts advise to start the tool and leave it running at minimum rpm, “hang the saw on the fence”. such an expression is common. This advice is a straight road to the engine overhaul, and it’s impossible to follow it in any case. The tool has to work, even if with a dosed load.

After completing the running-in it is necessary to make adjustment of the carburetor to the operating mode.

Running in of a chainsaw engine after repair

After the overhaul of the chainsaw engine, it is desirable, as for a new tool, to run-in. The process, in its essence, does not differ from the way the running-in of a chain saw, just bought in a store.

To make it clear, the details installed during the repair, as well as parts of a new tool, are running in over the same period of time, so the conditions that contribute to this should be provided in the same manner. So, for successful running-in of the engine after the overhaul it is necessary to perform the following actions:

  • Enrich the fuel-air mixture by unscrewing the H screw by ¼ of the position in which the maximum engine speed is reached, and for chainsaws that do not have the ability to adjust the carburetor, increase the amount of oil in the mixture with gasoline.
  • Let the engine cool down more often.
  • After the first four hours of operation, dilute the fuel mixture for domestic models according to the manufacturer’s manual, and for models with carburetor adjustment, bring the maximum engine speed, by adjusting the H screw, to the normal value.

To summarize, I would like to mention the following main points. A chain saw should not be run in idle for any reason. For lapping a domestic tool, it is enough to slightly increase the amount of oil in the fuel mixture. Chinese chain saws, like other machines, need a running-in period, and it is done in the same way. During the first four hours of use the right actions are the key to the chain saw’s reliable performance over its entire service life.

Finishing off your chainsaw. Adjusting the carburetor adjustment for the maximum engine rpm by adjusting the screw H

The running-in process for a chainsaw is very important. it is from it depends on the quality of the running-in of the key parts of the chainsaw engine, as well as the further work of the tool in various conditions.

To properly run-in a new chainsaw, the owner needs to remember a few important points:

  • the running-in period is not the same for saws of different manufacturers;
  • Chainsaws of different production differ in engine brands, the percentage of fuel mixture, which means they need a unique running-in;
  • it is important to establish in which stroke of the chain saw the running-in procedure is performed. cyclic or idle (this information is obligatory in the instruction, which must be read before you start working with the chain saw).

To take the Husqvarna chainsaw as an example, its running-in is always done on a cyclic cycle only! The engine should run at high rpm, but with little power.

BEST way to Break in a New Chain Saw

Remember that if you violate the running-in conditions, you run the risk of not getting warranty repairs in case of a breakdown.

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