Chainsaw stalls on throttle, at idle or under load: causes and solutions
The work of the two-stroke engine is based on the interaction with the carburetor and the ignition system that provides fuel, air and spark into the combustion chamber. If these components and the piston assembly malfunction, it can lead to serious malfunctions. Unplanned shutdown of the engine when it is running is often caused by defects in key system components. Fortunately, in 90% of cases, you can identify the source of the problem and repair it yourself with basic skills and minimal time and money.
Let’s understand the reasons why a chainsaw cuts crookedly. It shows up when sawing under load, when the guide bar is pushed to the side little by little. It is especially noticeable when sawing wide trunk by double-cut method, first from the top, then from the bottom. As a result, the output is an uneven sawed surface, which in some cases is unacceptable. Example. facing bars.
- Uneven sharpening of the saw teeth. This is the most common reason why a machine cuts obliquely. Teeth should be ground to the same distance to avoid problems when sawing. Optimal solution is to buy a sharpening machine which adjusts to the most worn tooth of the saw mechanism. Or go to a workshop that has such equipment. Result. all teeth are the same size.
- The chain or tire used does not match the parameters. When buying these items, the width of the groove should be taken into account. It is not only important for the proper operation of the machine, but also for safety when sawing.
- The saw headset of the device is badly worn. If the machine is cutting poorly, there may be excessive wear on the front attachment. A visual inspection will indicate the problem. If the right or left side is more worn, the bar must be exchanged for a new one. If there is excessive wear, it makes sense to have the lubrication system checked. This is often the cause of excessive wear on one side of the chain.
In complicated cases it is better to have the machine repaired by a specialist workshop.
Sthil MS180 (STIHL 180) carburetor. No, I haven’t.
STIHL MC 180 chain saws in current and recent years are equipped with Chinese-made carburetors with only one adjustment screw. These carburetors membrane type almost can not be disassembled, because it is all sealed and primed. So to speak: Adjustment not, have not heard. In this case it is easier to buy a STIHL 180 chainsaw carburetor. They are available from both STIHL original (also made in China, but by an STIHL plant) and third-party (also Chinese) carburetors.
It’s worth noting that despite the Chinese production the original STIHL 180 carburetors are very reliable and seldom let owners down then the original 2500, that is almost 4 times more expensive.
stihl ms180c that wont idle and runs rough watch this
Repair kits are available for chain saws which are 5 or more years old.
How to adjust the carburetor chain saw STIHL 180?
We can only adjust the idle speed. What is it for and how do I know when I need to adjust the idle speed on my STIHL 180 chain saw?? It is necessary if the circuit does not stop when idling, which can lead to injuries, unstable operation of the saw as a whole.
The fuel filter is dirty
If the air filter option doesn’t work for you, then try changing the fuel filter. It is in the gas tank and is attached to the hose, through which fuel is taken from the tank.
This hose should be carefully lifted with something and take out of the gas tank its edge, on which the filter is fixed. The variant to work without filter, as in the case with the air, is better not to apply, because you can not know exactly whether there are any unnecessary impurities in the fuel.
So just change the fuel filter for a new one and try to work. If everything is fine, congratulations. you have found the cause.
Why does the chainsaw quit when idling?
Although the chainsaw is not a complicated machine, from time to time it has some defects which can only be corrected by disassembling the. Some examples of malfunctions are as follows:
- The chainsaw won’t pick up speed;
- The chainsaw stops functioning in the cut;
- The chainsaw starts and stops;
- chainsaw loses power;
- Your chain saw stops when you press.
Most malfunctions are caused by a malfunction of the engine or by faults in other systems and components. Proper handling of the machine is important. If all the rules of use are followed, problems are likely to be the most obvious. In searching for the cause of a problem it is wise to begin with checking the simplest part of the chainsaw and end with the most complex part.
Why does the chainsaw not pick up speed??
Starting is a complex, multilevel process that involves almost every part of the chain saw. That is why the fact that the chainsaw loses rpm, starts up irregularly and feels sure of itself only at idle should be considered from different angles.
- A defective motor. its motor life could be exhausted and the piston rings and cylinder could be worn, deformed or even corroded;
- A faulty spark plug or coil which does not provide the spark necessary to ignite the fuel/air mixture;
- carburetor screws unbalanced and a number of reasons that could cause it to malfunction.
STIHL 180 Throttles on the Hot Gas
Everyone has a defective chain saw and the STIHL MS 180 is no exception. Today we will try to solve such questions as: why does the chainsaw stalls at higher rpm, also at idle and at full throttle? Check out our troubleshooting tips to troubleshoot the STIHL 180 on the STIHL chain saw.
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Why does the chainsaw quit when you accelerate?
Your chain saw is running fine when idling, but sharply pressed on the gas and stops. What might be the reason? At once it is clear that it is not in the ignition (lack of spark), t. к. If the ignition is faulty and there is no spark, the tool will not start. That leaves the fuel system.
To find out why the STIHL STIHL 180 chain saw fails to operate normally, it is necessary to run a full diagnostic of the fuel system. Read here about chain saw faults STIHL 180 and remedy.
Checking the filter
First thing to check is the fuel filter.
In some cases the filter can become clogged with dirt and is unable to pump a sufficient amount of fuel. There is therefore a shortage of fuel in the system, which means that when you accelerate the STIHL 180, the fuel burns out and a new one has not yet had time to be delivered STIHL chain saw Stops. If the fuel filter is clogged, you may also notice a noticeable drop in the chainsaw’s power at maximum speed, but this is if it is only slightly contaminated.
On the World Wide Web, it is reported that a clogged air filter on the STIHL chain saw no longer cuts off the STIHL 180. I would like to refute this incorrect information and tell you that the STIHL MC 180 carburetor is fitted with a compensator which is designed and installed to take the air necessary for the STIHL 180 bypasses the contaminated air filter. Of course the performance will be slightly reduced if the air filter is clogged, but you can be sure that it will not choke. Another reason for the loss of power is the piston’s wear and tear. and if so, the STIHL MS 180 chain saw needs its piston repaired.
One of the reasons why your chain saw doesn’t provide more power when you accelerate, or why it stops is because of a faulty carburetor. The STIHL 180 was working fine and then it was put away for a long time without use. After that, he started, and at idle it works well, but when you press the gas may stall. Why does it stop?? The reason is in the jammed carburetor valve nozzle. Of course, it is not 100%, but the probability of such a fault is high. We recommend reading the article on carburetor construction and repair STIHL 180.
In order to check the injector, you must remove the carburetor and disassemble it. To remove, it is necessary to unscrew two nuts fixing the air filter and the carburetor, then remove the air filter and the engine control lever, having disconnected thus a rod of control of the air flap from the carburetor. Then you need to pull the carburetor a little towards yourself, and disconnect the fuel supply hose.
It is necessary to take off the fuel hose as carefully as possible and prepare a plug for it beforehand because. к. Fuel should come out of it.
After removing the carburetor, it should be blown and cleaned of dirt, only after that the carburetor can be unclogged.
Unscrew the cover of the main chamber of the carburetor, this is the one on which the compensator is installed on top. Then, with the help of a bolt 8 mm long and at least 50 mm. We knock out the valve.
The STIHL 230 nozzle stops after a short period of operation
It is necessary to knock out the valve having placed the carburettor on the wooden base, it will protect the carburettor from the body damage.
After removing the nozzle, you can blow it out with a compressor. The valve must only let air through in one direction, if you can blow freely in both directions, then it is defective and must be replaced by a new one. To assemble the chainsaw after the valve has been repaired, it is necessary to follow the order of disassembling in the reverse order.
To watch visually how the repair of the carburetor happens, to be exact how to knock out the valve from the carburetor body correctly you can watch video.
Another common reason for the STIHL 180 to choke on higher RPM is air intake in the carburetor. It is possible to check this only having a special tool, but it is worth noting that if preventive work with the carburetor has not been carried out for a long time, you can install a new set of gaskets in the carburetor. In some cases it is the solution to a leaking carburetor.
Dismantling the carburetor for replacement of gaskets, you need to carefully inspect its needle valve, press the rocker and check its lifting. Sometimes, especially after a STIHL chain saw has been sitting for a long time with fuel in the carburetor, the needle may burn into the carburetor housing and not perform its function. Simply speaking the needle valve will not leak the fuel mixture. In that case, the saw will not work.
Why does the idle speed stall?
The first and most common cause of this malfunction is improper adjustment of the carburetor. You can adjust the idle speed yourself, for this you need to have a STIHL adjustment screwdriver, which is supplied with the unit. The regulating hole is on the right side of the STIHL 180 on the handle. и.
If a STIHL chain saw will go flat when idling, it is almost 90% sure that there is something wrong with the fuel pump. normally an air leak in the crankcase through the oil seal or, more often, through the crankshaft oil seal. Air intake reduces or completely stops the pulse of air flowing through special channels to the chainsaw’s fuel pump. The result is that the STIHL 180 chain saw does not get enough fuel and cuts the throttle at idle speed.
To do this, use a special tool called a vacuum gauge.
The second way to check the performance of seals, is to pour gasoline into the crankcase and look at them, if the seals will leak gasoline, then they can not provide normal pressure in the crankcase, which would make idling impossible. When working at high RPM, with leaky seals, there is a chance of jamming the crankshaft bearings.
The procedure for checking the crankcase and oil seals of the STIHL 180 for leaks is as follows:
- Remove the top cover.
- Dismantle the air filter housing and carburetor.
- The chainsaw handle can be removed.
- Unscrew and remove the starter motor.
- The side cover and drive sprocket are removed from the side opposite the starter.
- A piston stopper is installed in the spark plug hole, or a piece of string from an old starter with knots tied to it is stuffed into the cylinder.
- Unscrew the flywheel and clutch and remove the parts. It is worth knowing that the chainsaw clutch has a left-hand thread and is unscrewed clockwise.
- Removing the gear of the oil pump drive.
After taking the STIHL MS 180 chain saw apart you can see the seals, fill the crankcase with gasoline and check for leaks. Fill the crankcase, you can through the fuel window in the cylinder, to do this, the piston must be raised as high as possible. If it is leaking you need to replace the leaking oil seals or re-seal the oil pan. Reassemble the STIHL 180 by following the reverse sequence.
Why does the engine stop when full throttle?
It is very common to hear the question why a chain saw cuts out at full throttle. There are several possible causes. First of all, it is important to know how the machine stopped. Let’s assume the machine was running fine and then suddenly, for no apparent reason, it just stopped and the starter motor wouldn’t start. In such a situation you can be 100% sure that the chainsaw is jammed and its overhaul should be started.
The second situation is when a STIHL 180 chain saw is running fine, then gradually over a short period of time it loses power and shuts down, with overheating of the cylinder. In that case, most likely the cause is air leaking under the rubber tube that connects the carburetor to the cylinder or a gap. The mixture has been depleted, resulting in overheating. You can eliminate the problem by changing the hose.
Filters are often clogged, especially when daily. The air filter can be disconnected and flushed under a stream of warm water. Before re-installing. dry out thoroughly.
If no fluid leaks from the carburettor after disconnecting the fuel hose, the carburettor is blocked. It can be cleaned or replaced with a new one.
If the tool is used frequently, the gasoline pump may not work properly. After all, every part has an expiration date. It should be replaced or go to the service center.
Why the STIHL chain saw will not start
For a preliminary diagnosis of the cause, check the operation of the gasoline pump, the appearance of the spark plug, the fuel supply, the functionality of the carburetor and the condition of the filter. Check for proper functioning cylinders, pistons, muffler, crankshaft bearings. After preventive measures try to start the chainsaw. Lack of lubrication of friction parts is also a factor in poor performance.
Lack of spark
The spark plug is checked. Various factors can affect the function of the element. Testing the mechanism reveals the cause:
Such conditions cause a build-up of soot on the spark plug contacts. Subsequent corrosion of conductors causes no spark in half of all faults. This happens because the gap between the modular contacts changes. The following is done to check the spark:
- the tip of the high-voltage cable is removed;
- spark plug is unscrewed;
- the spark plug is put back in place;
- The spark plug is leaning against the cylinder with its wide end;
- the starter motor is started.
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If a bright spark resembling lightning appears between the electrodes when starting, then the ignition unit is functional. If there is no flash, the entire element is cleaned and the gap between the conductors is adjusted. Sometimes there is no gap between the flywheel and the ignition coil. When the flywheel rubs, scratches can be seen on the outside of the flywheel.
Faulty ignition coil
Module or coil is not disassembled, its suitability is difficult to determine without testing equipment. Modern ignition systems are rugged, lightweight and small in size. They are characterized by an almost failsafe function. Problems with chainsaw malfunction due to the ignition coil can be fixed yourself.
Test the lead wires for damage (t. ч. internal), which is caused by vibration leading to friction. If no cracks are found, the ignition coil needs to be replaced. Sometimes a faint, barely perceptible flash when the saw heats up indicates a module malfunction. This is due to an increase in coil temperature, which leads to an increase in transistor resistance.
The peculiarity is that at the beginning of work, the spark may appear, but after prolonged use it becomes dull and disappears. Modern ignition coils are not repairable in the home workshop, so they are replaced with suitable elements.
after unscrewing the plug there is a wet film on its surface. This indicates an excessive supply of gasoline into the combustion chamber. This is the reason why the tool does not run or stalls, t. к. fuel does not ignite.
Another retarding factor is a clogged breather. a small hole in the cover of the gasoline tank. Clean it with a needle, otherwise the STIHL MS 180 chain saw will not start. To determine the improper fuel supply carry out the following steps:
- Remove the spark plug;
- in the hole of the spark plug pour a syringe 2 cc of gasoline;
- put the ignition device in place and put the cap on the high-voltage wire;
- set the lever to the hot start position;
- yank the starter handle a couple of times.
If the tool starts and immediately stops, then the fuel line is tested further. Check the gasoline filter, the splash from the engine crankcase, the integrity of the partition in the pump when unscrewing the cover.
Crankshaft bearings failure
If the bearings are defective, a slight backlash can be felt. Pull the STIHL MS 180 handwheel from side to side to locate it. The movement indicates that the handwheel is moved towards the electrodes by its own magnets, resulting in no spark. To remove the mechanism, remove the cutting element, remove the filter and clutch cover. To lock the crankshaft, remove the cover of the recoil starter and tighten the two bolts.
Unscrew the clutch with a clockwise wrench. Remove the drum with sprocket, replace the old clutch and screw it in as far as it will go. Crankshaft is blocked to prevent breaking the starter motor. The mechanism is assembled in the reverse order. To tighten, tilt brake handle forward, start tool and then remove brake.
Rarely, defective bearings are detected (diameter of holes in the cage is enlarged). To determine, disassemble and measure with a micrometer. Broken bearings are indicated by regular knocking. In this case an urgent repair is required, i.e. к. If the crankshaft is damaged, the piston group and cylinder will fail.
Fills the spark plug
In this case, the spark is unable to ignite the fuel, which flows in large quantities into the furnace to burn the combustible mixture. If the spark plug pours, the carburetor is defective or the cold engine does not start correctly. Perform engine purging procedure with the ignition off and away from open flame. To ensure ignition of fuel at startup, the mechanism is cleaned
- unscrew the spark plug, wipe it dry, dry it for half an hour;
- A big layer of soot is removed with a file;
- The gap between the contacts is adjusted;
- The tool is turned upside down and the gasoline is drained;
- in this position jerk the starter several times (to remove fuel residues);
- Reassemble in reverse order.