Remove the flywheel from the Stihl chainsaw

Principle of operation

Before identifying a malfunction and repairing the Stihl 180 chainsaw, you should study the principle of its operation and what structural elements it consists of. As part of the chainsaw, its main element is necessarily present. a two-stroke engine. It is he who is responsible for the reliability and performance of the device. The engine is involved in starting the chain drive and keeping it moving by the centrifugal clutch. In addition to the electric motor, the chainsaw includes:

  • starter;
  • flywheel, it is also a cooling unit;
  • ignition block;
  • clutch and brake mechanism;
  • carburetor with STIHL compensator;
  • air filter;
  • fuel and oil tank;
  • muffler;
  • anti-vibration system.

Fuel from the tank enters the carburetor, where air from the cleaning unit is mixed with it. From the carburetor, the air / fuel mixture enters the engine. The saw carburetor has one miter screw that controls the idle speed. All device settings are made at the factory and ensure optimal flow of the fuel-air mixture.

The mixture is ignited in the engine cylinder, and the engine is started with the help of the starter. Under the action of the piston, the shaft, which is part of the crank mechanism, begins its movement. There is an asterisk on the shaft, on which the chain links are put on.

The chainsaw uses a single-cylinder engine. A clutch is used as a protection mechanism, which allows the electric motor to idle in the event of a chain jam. At the initial revolutions, special pads located in the radial direction are pressed by springs against the middle of the shaft, thereby preventing it from rotating. At high rpm, the centrifugal force increases, which causes the springs to compress. The pads are squeezed out from the center of the shaft, the sprocket rotates and the chain starts.
The electrical circuit of the device is involved in the ignition system. Due to the use of a flywheel with magnets, an electromotive force (EMF) arises during rotation, which leads to the appearance of a current in the electronics unit. The block sends a signal to the candle, provoking the appearance of a spark at its terminals. This spark ignites the carburetor mixture. After a successful start, the chainsaw begins to repeat all work processes in a cycle.

The chain of the device is assembled from teeth and connecting elements. To protect the user from kickback, the device is equipped with a brake system. Oil is supplied in automatic mode under the action of a pump.

Assembling the Stihl 180 chainsaw

Assembling the stihl ms 180 saw back is quite simple, the main thing is to adhere to the following algorithm:

  • Install the piston on the connecting rod, the arrow on the piston should point in the direction of the Stihl 180 chainsaw, and the side of the crankshaft, which is intended for installing the flywheel, is located to the left of the piston;
  • Carefully insert the piston back into the cylinder, the place for mounting the coil should be on the side where the flywheel is installed on the crankshaft;
  • Install the bearings, oil seals, circlip on the shaft and lower the entire assembly into the seat in the cylinder;
  • Next, degrease the crankcase installation site and the crankcase itself, then grease with a sealant and, setting in place, tighten the 4 fastening screws;

To reassemble the Stihl 180 saw after the engine is assembled, the reverse sequence of disassembly must be followed. It is important to treat the process carefully and do not forget to install the rods on the carburetor, and connect the ignition wire.

Below you can see the disassembly of the Stihl 180 in the video, it was made for inexperienced users, it shows the whole process in detail.

Dismantling the Stihl 180 chainsaw and assembling it, with some experience, is quite simple, the main thing is to thoroughly clean the saw before work and not to rush. In order that small parts are not lost, you need to use containers in which, in the process, you should lay out the parts.

Types of breakdowns

Before starting work on finding the malfunction of the Stihl 180 chainsaw, it is necessary to prepare the tools and allow the engine to cool down, thereby excluding unintentional start.

For a qualitative elimination of a breakdown, it is necessary to analyze what actions preceded its appearance. If we proceed from the fact that the chainsaw is equipped with an electric motor, the main breakdowns are primarily associated with it. The most common malfunctions include:

  • inability to start the engine;
  • self-shutdown of the device during operation;
  • the electric motor does not pick up the required speed during operation;
  • the appearance of extraneous noise and a burning smell;
  • oil leak.

Common breakdowns of chainsaw consumables include chain breakage, which always occurs between its links. When connecting the links to the rivet, you will need to firmly press their side parts and flare them. If the protrusions are worn off, then it will not work to rivet them, so contact welding will be needed.

In addition to breaking the chain, it can also stretch. This happens when using a low-quality chain or in case of its frequent overheating, as well as wear of the driven sprocket. Overheating is associated with a disruption in the oil supply caused by blockage of the injection. To eliminate the malfunction, you will need to purge the oil supply system. In the event of stretching, the chainsaw works in jerks. To restore normal operation, you can try to remove one link, while it should be borne in mind that riveting the links is not so easy.

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When searching for breakdowns in the device, it is recommended to follow the following sequence of actions:

  • examine the general condition of the device;
  • check the mixture level in the fuel tank;
  • inspect the unit responsible for starting the saw;
  • diagnose the performance of the candle and the condition of the sealing ring;
  • evaluate carburetor.

Some types of malfunctions can be eliminated by simple actions such as cleaning the components. But malfunctions associated with the carburetor or ignition system require a complete or partial disassembly of the saw.

Dismantling the clutch and oil pump drive

Before disassembling the clutch, the drive sprocket must be removed. To do this, carefully remove the lock washer from the grooves on the shaft and remove the sprocket and needle bearing.

With a high head 19, you need to unscrew the clutch. The thread on it is left-handed, so it unscrews towards the tire, and not the back of the Stihl 180 saw.

Having unscrewed and removed the clutch, you need to immediately remove the reflective plate and the oil pump drive, this is easy to do, because they are put on the shaft without any fastening.

Common breakdowns of Stihl 180

Common malfunctions on a Stihl chainsaw include:

  • Breakage of the starter cord;
  • Drive sprocket wear;
  • Leaks in the chain oil supply system;
  • Wear of the oil pump worm gear;
  • Air leaks through oil seals into the engine crankcase;
  • No spark on the spark plug;
  • Lack of fuel supply in case of malfunctions in the carburetor (we will not dwell on them, since the repair and adjustment of the chainsaw carburetor is a fairly wide question and will be discussed in a separate article);
  • Breaking the eyelet of the seat under the engine control lever.

Now we will consider the malfunctions in more detail and start with the repair of the oil pump.

And also watch the video Dismantling the STIHL MS180 chainsaw

Good evening, I have such a problem. saw Stihl ms180c, worked a little, saw trees last time, there were interruptions in the operation of the engine. Then it stalled. what I did not do, 0, disassembled the blew, cleaned, the carburetor, assembled it, started up with a half-turn, worked fine, gained momentum, stalled, and again 0, replaced the spark plug. ignition coil, 0, disassembled carburet, clean, blew, assembled, started. and worked again, the gasoline ran out, I poured it a little, poured gasoline, everything is 0 again, the candle is wet, there is a spark, tell me. how to solve this problem, described meticulously, to make it clearer, can anyone come across this problem.

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Chainsaw flywheel removal on a old chainsaw without a flywheel puller.

Hello, and when you turned out the candle, did you try it? is there a spark? it happens that there is a spark and everything seems to be in order, but the saw still does not start. I really had the same situation on another brand. it turned out there was no compression. changed the oil seals and seems to be still working (for the second year already). there is still a problem. filters. changed them? in general, a bunch, each time different answers, so as not to bother for a long time, try the service, if it is too expensive, then.

Removing the flywheel

The flywheel of the Stihl 180 chainsaw is twisted with great effort, so a head with a metal knob is required to remove it. The nut holding the flywheel is unscrewed by the head by 13.

To block the crankshaft from turning, you need to unscrew the spark plug and install the piston stopper through the spark plug hole, if it is not there, you can use the old cord from the starter, with knots tied to it and immersed in the cylinder through the spark plug hole.

It is strictly forbidden to keep the flywheel from turning by installing a power screwdriver and other tools between its ribs and the body of a power screwdriver, with this method of blocking from turning, the flywheel blades are not able to withstand the load and break off.

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After the piston is locked in the cylinder, you can unscrew the flywheel nut. The thread in the nut is ordinary, so you need to turn it to the left. Having loosened the nut, it is not necessary to remove it to the end, it is enough to unscrew it until its upper edge is equal to the tip of the shaft, after which a soft metal drift is installed on the nut and a sharp blow is made on it. Thus, the flywheel from a sharp impact jumps off the shaft and can be easily removed without the help of additional tools.