My STIHL STIHL 180 chain saw operates at high rpm

STIHL 180 Large Idle Speed

STIHL STIHL chain saw MS 180. The problem is this. Before preserving for the winter on the advice of mechanics, I dropped 4 drops of motor oil (STIHL) in the hole in the plug. screw the spark plug in. Now I’m going to go to the cottage, decided to take a look at the saw. Pulled the starter and it wouldn’t turn! Unscrewed the spark plug, it’s oily, wiped it back on. Same thing. Unscrewed, cranked the starter without a spark plug- everything spins perfectly. Screwed it back in, starter doesn’t turn. What else could it be??

Flush the chain saw with pure, undiluted gasoline, pour it straight through the spark plug hole and slowly crank the starter. Then dump the fuel and start over. All that work, then dry the chain saw and the spark plug, before you try to start it. If you’ve learned how to can, learn how to can, not just pull and go.

Tell me why the starter motor might be jammed? STIHL 180 chain saw is brand new.

You won’t know unless you take it apart. Maybe the starter cord didn’t fit snugly, or maybe the sump was in the way. Stiles starters are pretty reliable and durable. No structural problems, mainly dirt or heavy use. If your chain saw is new, take it to a service center and it will be repaired under warranty.

I have noticed a peculiarity with my STIHL MS 180 chainsaw: when the tank is out of gas, the engine rpm idle rpm increases and the chain starts to rotate even when the trigger is released. I step on the gas and the chainsaw stops. It lasts a few tens of seconds, then the saw stops. I haven’t observed such a phenomenon in automotives, when the carburetor is low on fuel the engine speed increases. Why does this happen??

It is a common thing with two-stroke engines. If I decrease the gasoline flow into the carburetor, the mixture gets leaner. As a consequence. RPM increase, deterioration of acceleration. Associated with it short-term overheating of the cylinder head. It will not destroy the engine, but it will not make it healthier. Avoid letting the fuel run all the way out of the tank.

I have a STIHL MS180 chain saw and use it for the country season when I cut firewood. The chain has recently started to lose its throttle response, not turning at all or jerking. it is impossible to saw. What could be the problem??

For a brand-new chain and sprocket, the tensioning should be exactly as specified. so that the lower branch does not sag. and the upper one could be pulled out with the fingers to the height of the leading link. Then the chain will be loose enough on the bar. But, as the sprocket teeth gradually wear out, the sprocket pitch decreases. And the gradual stretching of the chain increases the chain pitch. there comes a time when the chain and sprocket steps don’t match each other anymore to the point where the recommended tensioning is causing the chain to have a hard time moving. In this case we recommend that the tension be slightly reduced. Up to the appearance of some sag of the lower branch. By the way, for the same reason it is recommended to use a pair or even three chains on one sprocket. In this case, and the wear is even and will not be an accelerated wear and the new chain on the old, partially worn, sprocket.

But if I press the gas button for about 30-40 seconds it would work fine. Produced 3l of gasoline, filters clean, dealer oil.


The STIHL 180 is easy to adjust, it has one screw, which you can use to correct the idle speed a little.

No L and H screws in the carburetor on the 180, like on other chainsaws. This is made to inexperienced user did not twist that it is not necessary to twist and did not harm chain saw.

Of course Germans are good, but sometimes, especially after the replacement of the piston group and the installation of non-original, on the chain saw is lost idle stroke. If it were possible to adjust the fuel mixture, the problem would be solved in a couple of seconds, and so we have to climb into the main chamber and adjust the position of the needle valve rocker.

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Chainsaw engine stops after reaching maximum rpm

Power unit stalls at high rpm due to failure to meet the electronic unit’s performance specifications. Failure is more typical for budget Chinese-made chainsaws.

Failure can be caused by:

  • lack of fuel mixture in the float chamber due to jamming of the valve;
  • fuel filter or fuel tank nozzle in the fuel filler flap is clogged.

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Unit also stalls at high RPM due to a contaminated intake filter. Similar signs are typically seen when a chain saw starts up in standard mode and then shuts down during warmup.

STIHL MS 180 Repair / carburetor disassembly and assembly / cuts out at idle speed

STIHL MS 1800 chain saw. What’s the right way to deal with a chainsaw that won’t stop working?

According to the recommendations of the manufacturers spark plug should be changed annually, regardless of the intensity of operation of the tool. Failure to follow these tips leads to quite a natural result: malfunctions on the Idle speed

Typical ignition system defects are as follows:

STIHL 180 chain saw cuts out at idle speed.

  • Plug becomes soaked with fuel at startup. Remove the spark plug from its housing, dry it and if possible, blow it out with compressed air. Drain the rest of the fuel from the cylinder through the setting hole, blow out with compressed air. Then install the spark plug, connect the high-voltage cable, start the engine.
  • Lack of spark on the spark plug electrodes. Disconnect the ignition cable and check for a spark. If the spark is normal, check the connection, fix the detected defects. Lack of spark on the high-voltage wire indicates a malfunction of the ignition unit. This device is not repairable, you need to replace it with a new one.
  • The gap between the electrodes on the spark plug is abnormal. This parameter for different types of devices can be in the range of 0.2 to 0.5 mm. Check and correct with a dipstick or caliper. You can check the correct value with a dipstick or caliper in the owner’s manual of your tool.
  • By the appearance of the spark plug you can determine the direction of the search. If the spark plug after several attempts to start the engine is dry, it means that the cylinder does not receive gasoline. Check the fuel system and carburettor.
  • Black soot or carbon deposits on the electrodes indicate improper carburetor adjustment or a clogged air filter. Probably a low-quality fuel with a high oil content is used. If the ignition system is working properly, the electrodes have a uniform gray color and brown deposits on the insulators.

READ What Oil to Add to Gasoline for a Chainsaw


You may need to adjust the carburetor on your STIHL chain saw if the fuel quality or altitude changes (low air pressure), or if atmospheric pressure, temperature and humidity change. Tuning the chainsaw carburetor allows you to achieve good chainsaw performance when the external operating conditions deteriorate. Also the adjustment of the carburetor of a chainsaw allows to prevent oil starvation and motor failure due to insufficient lubrication entering the cylinder with depleted fuel consistency.

STIHL chain saw idle speed adjustment video.

Tip: To check the tightness of the motor is amazing to use a special device, t.е. A special pump with a pressure gauge. At first remove the carburetor on the chainsaw and put a sealed plate plug on the cylinder inlet window with a flange to connect the hose from the pump. Spark plug for tightness is also an option to plant on sealant. It is also necessary to remove the muffler, and to install a sealing plate with a rubber gasket on the cylinder outlet window. Then you need to put the piston in the top dead center and connect the hose from the pump to the flange. Then pump the air into the engine to 0,9 atm. and look at the arrow on the manometer. if it stands on one place, it means that the piston of the engine is tight. Then let the air out, switch the device (pump) and start pumping air out of the cylinder, creating vacuum in the engine with pressure gauge reading at.0,5 atm. We look at the arrow on the pressure gauge. if it is in the working place, it means that through the glands or other seals in the engine there is no air leakage (which aggravates the work of the chainsaw does not give the right to perform the carburetor adjustment chainsaw). So we check the engine for air drainage and compression.

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What to do

Use the power tool according to the manufacturer’s manual. Only after checking the tension of the chain does the machine start. Simultaneously control the filling of the tanks with combustible mixture and oil, the device is firmly secured in the hands. If the mechanism refuses to work when all the rules are followed, then the.

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How to start a STIHL chain saw: Instruction manual

The tool builder has taken all measures and has designed a manual so that the machine is easy to start. The user will keep himself safe from injury if he follows the suggested intervals:

  • The ignition is turned on and the engine handle is placed in the down position. The air inlet from the air filter is shut off by the carburettor flap. To start the chainsaw correctly the throttle plate must be open so that the mixture becomes richer.
  • The lever is placed in the throttle position. The starter is jerked several times until the first spark is felt. If there is a flash, the machine is ready to start. The machine is running at high rpm because the throttle membrane is closed. Pull and release the throttle trigger to return it to idle. RPM is quickly returned to normal.
  • No accessories are fitted as standard on the STIHL MC model so that the lighter version of the machine can be fitted as standard.

Idle speed adjustment

Before any adjustment the tool is serviced. To be able to perform the no-load adjustment efficiently, it is necessary to perform a preventive maintenance procedure:

To adjust the mechanism at idle speed, the appropriate adjusting screw is used. Its rotation depends on the desired setting:

  • When doing the standard setting, turn the screw against the clock hand until it is just as tight. Then make two laps in the direction of the arrow.
  • If the saw is working at a low RPM, turn the spindle clockwise until the chain starts to run. Then make half a circle in the counterclockwise direction.
  • At high frequency, the regulator turns against the hand of the clock until the chain stops. Then continue turning another half-turn in the same direction.
stihl, chain, high

Adjusting the idle will not work if there is air leakage into the engine through the gasket, acceleration pump, seals, or other reason.

Adjusting the ignition

Gasoline engines are equipped with an ignition system that ignites the fuel. Flash timing affects engine performance. The chainsaw ignition adjustment is not done in mass production in the factory. Marks are aligned on the respective rotating elements. Incorrect adjustment leads to the engine starting and stalling.

Before adjustment, check that the spark plug is dry and that the ignition circuit is working. The spark plug voltage cable is brought to the cylinder with a short gap and the starter is started. If there is no flash, test cable with a probe. Then check that the cable to the release button is in good condition.

If the cables are undamaged, the ignition coil is checked. This is done with a special tester to test the device. Readings on the gauge must match the coil specifications listed in the instruction manual. If discrepancies are found, the ignition unit is replaced with a functioning device.

The reel can be damaged by vibration from dropping or bumping the tool, so work with care.

Crankshaft bearing replacement

First measure the compression, if there is no compression, then the cause lies in the failure of the piston group.

The required pressure in the cylinder should be 8 atm, if it is lower, then perhaps the cylinder and piston, rings, crankshaft bearings are worn.

To find out about the state of the piston system, you need to disassemble the saw and remove all the main parts of the mechanism.

1) STIHL MS 180 chain saw malfunctions: throttle trigger jams or throttle trigger stops moving over time.Cause: Translucent tar buildup on carburetor throttle axle, causing the throttle mechanism to jam. Resin is formed when gasoline dissolves the poor quality coating on the choke. Clean carburetor choke axle with acetone and tin the choke with tin.

2) Chainsaw malfunction: Chainsaw “doesn’t pull”.Cause: clogged carburetor.Chainsaw repair: Disassembling the chainsaw carburetor and cleaning it. Particular attention during carburetor cleaning should be paid to cleaning the additional filter (mesh in the carburetor chainsaw). remove the largest cover on the carburetor, remove the membrane under it and clean from dirt the mesh in the recess (careful not to lose this mesh). It goes without saying. clean with a thin copper wire, flush and purge all the channels in the chainsaw carburetor.

stihl, chain, high

3) STIHL chain saw 180 malfunctions: The idle speed of the chain saw is too high (no automatic idle speed adjustment is working).Cause: Air intake at the crankshaft oil seals or somewhere else.Troubleshooting: Replace the crankshaft oil seals and check other possible leaks.

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4) Saw malfunction: After carburetor is disassembled, it’s hard to start the saw, there’s white smoke coming out of the muffler.Cause: During disassembling the carburettor lost the spring under the needle lever, as a consequence, the needle does not lock the fuel supply and the spark plug “fills” with petrol.Fixing the chain saw: Find and place the spring under the needle lever in the carburetor.

The chainsaw won’t start or run properly.Cause: spark plug gets stuck with gasoline because of stuck carburetor needle or cam lifted high. Flush and blow out the carburetor, set the rocker arm correctly.

Why the chainsaw won’t start. Causes and Solutions

Starting up a petrol chainsaw is a multi-level process that involves almost every part of the machine. One of the first signs of chainsaw motor malfunction is the lack of engine RPM increase. This can manifest itself in different ways: the engine may work with interruptions at idle, or not to gain the required revolutions under load. That is, when you squeeze the throttle trigger. In any of these cases, you need to disassemble the tool and carefully inspect its internal construction.

stihl, chain, high

Breakdowns, due to which the chainsaw does not develop revolutions, are:

    engine failure. The first thing that can happen is wear of the motor, that is, its final exhaustion. This will be evidenced by numerous scuffs and burrs on the surface of the parts of the cylinder head, deformation of the crankshaft or through holes in other parts. In this case, the only thing that can help is to replace the motor, which is tantamount to buying a new chainsaw;

  • The settings in the carburetor are wrong. if the steel jets on the fuel assembly turned out to be displaced, they will need to be set according to the instruction manual;
  • A spark plug with oil or defective spark plug. The first thing to do is to clean the spark plug of dried-on engine oil. If all this has not helped and the chain saw is still not climbing straight onto the saw, it is time to change the spark plug.

To reduce the risk of spark plug damage, be extremely careful not to damage the spark plug stem when cleaning it. This is responsible for creating the spark that is needed to ignite the fuel.

Running in the STIHL MC 180. First-timer tips

If you have purchased a STIHL chain saw MS 180, it is absolutely necessary to service it. This is to ensure that the machine is running in perfect harmony with the machine’s main mechanisms.

Before the STIHL STIHL 180 chain saw is running in, it should be filled with a new fuel mix. You also need to add fresh chain oil to lubricate the STIHL 180 chain saw. Here’s how it goes from here:

  • You must first switch off the chain brake to prevent the housing from melting where the clutch is located. The brake also protects the operator from damage;
  • Then start the chain saw and let it idle for about 15 minutes. Every 30 seconds you have to pull the throttle lever;
  • After that the saw has to be switched to normal mode. During this time you should start cutting thin branches and gradually move on to work with larger branches.

As a rule, it does not take more than 30-35 minutes to prepare the tool. During the break-in period and if you continue to use the STIHL MS 180, you should always check that the chain is clear of nails and other hard objects.

Why does the chain saw choke?

You often hear the question “Why does the chainsaw quit when the engine is running? There could be several reasons. First of all, you need to take into account exactly how the saw stalled. Let’s assume that the tool was working normally and suddenly, without any apparent reason suddenly stopped and the starter does not turn. In such a situation you can be 100% sure that the chainsaw has jammed and you need to start its overhaul.

The second situation is when the STIHL 180 chain saw was working fine, then gradually over a short period of time lost power and stopped, and it is observed that the cylinder overheated. In that case, most likely the cause of air leaking under the rubber nozzle that connects the carburetor to the cylinder or its rupture. The mixture was thinning, which resulted in overheating. Eliminate the problem by changing the tube.

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