Stihl 180 Does Not Keep Single

The chainsaw stalls at idle: many owners of this tool face this problem. According to its device, it drank a rather simple tool. But there are times when it fails. The main problem in troubleshooting is determining the correct cause for abnormal operation.. Once the cause has been identified, repairing the defect is usually quite simple.

Stihl 180 Does Not Keep Single

Chainsaw device diagram.

Probable Reasons for Failure

The power unit of all chainsaws is a single cylinder internal combustion engine. For devices of this type, malfunctions such as a violation within the cylinder compression, a change in the ratio of the fuel mixture, incorrect ignition, poor-quality fuels and lubricants are typical. The main problems in the operation of the power unit are as follows:

  • The engine runs stably at minimum speed, but stalls with increasing speed;
  • Start-up is normal, and idle is unstable, quickly stalls;
  • Does not start.

Chainsaw electronic ignition circuit.

Abnormal idling can be caused by various reasons. They can be divided into several positions:

  • Reduced filter capacity (gasoline and air);
  • Abnormal operation of the ignition system:
  • Carburetor settings have changed spontaneously;
  • Malfunction of the elements of the gas pipeline;
  • Clogged exhaust ducts, silencer;
  • Defects of the piston, cylinder, valves.

Repair must begin with an external inspection and check for fuel in the tank.

Check and repair filters

The engine may malfunction or stall when there is insufficient fuel or air. Reasons. Clogged air or fuel filter. To check the fuel filter, it is necessary to remove the hose of the gas line from the carburetor fitting and direct it to some container. Then press the fuel pump several times. If the fuel is pumped normally, in clearly expressed doses, without dirt, then the fuel filter is working. If the jet is weak or fuel is not pumped at all. The filter must be replaced or cleaned if possible.

Clogging the fuel filter with sawdust is one of the reasons for a chainsaw breakdown.

The device must be removed from the fuel tank (after draining all fuel from it). In most models, the fuel filter can be hooked out of the wire through the neck. If the filter design is collapsible and can be cleaned, disassemble and rinse in accordance with the manufacturer’s recommendations. In another case, change to a new filter.

Similar problems can occur when the air filter is clogged with dust, sawdust, or dirt. If there is not enough air, the fuel mixture will be enriched, the process of burning fuel is difficult.

To check, remove the filter. When working, you need to take precautions so that dust does not enter the carburetor. The device must be cleaned and rinsed in warm water with the addition of detergent. After drying, if possible, blow with low-pressure compressed air, replace. If the chainsaw works fine, then the reason is eliminated, if not, you need to look further.

With constant use of the tool, it is recommended to replace the filters of the fuel and air systems after 3 months.

Checking the spark plug and ignition system

According to the recommendations of manufacturers, the spark plug should be changed annually, regardless of the intensity of operation of the tool. Failure to comply with these tips leads to a completely logical result: failures at idle, subsequent failure.

Stihl 180 Does Not Keep Single

Typical defects in the ignition system are as follows:

Faulty chainsaw candles.

  1. The candle was filled with fuel at the time of launch. It is necessary to remove it from the nest, dry it, and, if possible, blow it with compressed air. Drain the remaining fuel from the cylinder through the mounting hole, blow it off with compressed air. Then install the candle, connect the high-voltage wire, start.
  2. No spark on the electrodes of the candle. It is necessary to disconnect the high-voltage wire and check for a spark on it. If the spark is normal, check the connection, eliminate any defects found. The absence of sparks on the high-voltage wire indicates a malfunction of the ignition unit. This device cannot be repaired; it is necessary to exchange it for a new one.
  3. The gap between the spark plug electrodes has been violated. This parameter for various types of devices can be in the range from 0.2 to 0.5 mm. Check and adjustment must be carried out using a special probe or caliper. The required value can be found in the instruction manual of the tool.
  4. By the appearance of the candle, you can determine the direction of the search. If the candle turns out to be dry after several attempts to start the engine, then gasoline does not enter the cylinder. Check fuel supply system and carburetor.
  5. The presence of black carbon deposits or black deposits on the electrodes indicates improper carburetor adjustment or an air filter clogging. Possibly low-quality fuel with a high oil content is used. During normal operation of the ignition system, the electrodes have a uniform gray color and a brown coating on the insulators.

Check and repair carburetor

The principle of operation of the carburetor chainsaw.

If checking the ignition system, fuel filters, muffler did not give tangible results, the tool still does not want to work at minimum speed, you need to check the carburetor.

To adjust the operating modes on the device body are three screws designed to set the minimum rotation speed, maximum speed and idle speed.

On many models, manufacturers install only the idle adjustment screw to avoid incompetent attempts to adjust the device. In all versions of the device, the adjustment must be performed exactly according to the recommendations of the manufacturers.

If the adjustment of the device did not lead to the restoration of the normal operability of the tool, it is necessary to completely disassemble the device with inspection. It should be understood that the carburetor is a rather complex device, in the absence of experience it is advisable to consult specialists.

When disassembling, it is important to carefully inspect and flush all jets, air and fuel channels, and the filter screen. Damaged items must be replaced with new ones. The jets must be cleaned with a soft wire of the appropriate diameter.

It is advisable to carry out the work in appropriate conditions. The carburetor contains many small parts, the loss of any of them will make the device inoperative.

Check and repair the muffler

Clogged silencers should be left to soak in warm water with detergent, then wiped and dried thoroughly.

A muffler malfunction leads to a drop in the power of the tool during operation and stops in idle mode. Despite the apparent simplicity of this part, it is also important to monitor it. Quite often, the silencer is clogged. When working, it is possible that wood dust, sawdust, and resin particles get on the grate. High temperature contributes to their adhesion and accumulation, exhaust gases also form deposits on the surfaces of the spark arrester and other parts. Increasing over time, the layer reduces the capacity of the silencer and interferes with the normal removal of exhaust gases. The engine, figuratively speaking, is suffocating.

Repair of this unit is not difficult, quite possible for many tool owners. The device should be removed from the engine, cover the holes with a rag or other material. If the resulting layer is too hard, all parts can be left to soak in warm water with a detergent. After plaque softening, the parts should be washed with a rag or soft brush and wiped thoroughly. Inaccessible places can be blown with compressed air or blow dry. The use of mechanical means of removal is undesirable.

For the muffler to function normally over a long period of use, lubricants recommended by the manufacturer should be used, monitoring their expiration dates. The mixture must be prepared immediately before work and completely consumed.

Conclusion on the topic

Chainsaws, like most tools, require timely maintenance and care.

Failure to comply with this rule leads to tool failure, material costs, loss of precious working time at the most inopportune moments.