Huter chain saw stalls at idle rpm cause
Chainsaw stalls when hot
Sometimes the tool starts normally when the motor is cold, but as soon as the device warms up, the saw stops working. There are several possible causes for this:
- The carburetor is not working properly. The air-fuel mixture is too enriched and the fuel simply floods the spark plug. The problem is solved by reducing the flow of gasoline to make a mixture.
- Ignition coil defective. If the spark on the spark plugs is lost on a hot engine, it may indicate that the coil is not working properly. the part needs to be replaced.
- A spark plug is malfunctioning. The problem is very similar to a failed coil. It may be the coil or the spark plug that needs to be replaced.
Why does the chainsaw quit when heated up?
The situation, when a chainsaw starts when cold, but stops when warmed up, is familiar to many of those who work with them. The main reasons for this behavior are.
- Ignition module (coil) is defective. You can determine the problem by checking the spark plug on a cold engine first, and then on a hot engine. If there is no spark on a hot engine, it is worth trying to solve the problem by changing the ignition coil.
- The chainsaw carburetor is not properly set (floods the spark plug when it is hot). You can tell what the problem is by the way the saw starts when cold. If for a cold start the air damper does not need to be closed and the engine starts without preflash, then the fuel mixture is not formed correctly and after heating the engine the fuel floods the spark plug and makes the start impossible. The problem can be eliminated by adjusting the carburetor.
- The spark plug is faulty. In such a situation, similar to a faulty ignition coil, the spark disappears when the engine heats up. It is worth trying to replace the spark plug with a new one, and if that does not help, you should check the ignition coil and the gap between the coil and the flywheel.
You can check the ignition coil with a multimeter or replace it with a known good one. Check the primary and secondary windings with a multimeter in the resistance measurement mode. The resistance value of the primary winding, the working coil, is 1 kOhm. the secondary 4 kOhm.
Not enough oil in the fuel mixture
First let’s analyze the most unpleasant case. Why? Because before you do filter manipulation, it is better to make sure that your oil and gasoline are mixed in the correct ratio.
Here, however, it is worth noting that if your saw has been started many times (e.g. ten times), but continues to start and then stops again when you increase the rpm, then the fuel is probably all right. Otherwise it would just stop starting altogether.
But I still recommend to dispel the slightest doubt about the fuel quality as soon as your saw stalls at revs for the first time. Because if it is the fuel, you might end up having to pay a lot of money for repairs, as I said before. Otherwise, it might still work out. To remove all doubts you should drain your tank of old fuel and add freshly made fuel in which the oil and gasoline are mixed in the right proportions.
For the correct ratio you might look in the instruction manual of your saw. If you have lost it, look at the ratio on the oil package. It is usually 1:50 or 1:40. If you use non-native oil (for STIHL chain saws, for instance, little STIHL is “native”) I recommend using the 1:40 ratio, even if it says 1:50 on the oil package.
I personally use a medical syringe and a measuring jug in which you can clearly measure one liter of gasoline to get an accurate dosage. I pour a liter of gasoline in a container, fill up a syringe with 25 (at 1:40) or 20 (at 1:50) cubes of oil and add it to the gasoline.
After preparing a new mixture, drain the previous mixture from the tank, in which we are unsure, and pour in a fresh mixture just prepared.
Now that you have done everything to dispel any doubts about the quality of the fuel, let’s move on to further actions.
As I wrote above, if you don’t have enough oil, scuff marks can form on pistons and cylinder walls. and they almost always do. If you are lucky and no scuffing occurs, with a new fuel mixture prepared in the correct ratio, the chainsaw should start running normally.
If scoring has occurred, the saw may start and stall a few more times, after which it will stop starting at all. I feel sorry for you in this situation, because you will most likely need to replace the piston group, which will cost a lot of money.
If your chain saw still fires and shuts down at high rpm, then you can manipulate the filters.
Your Chainsaw Stalls? You Can Fix It, Here’s How
Why the chain saw does not rev up and shuts down
If the saw can’t pick up speed or stops when you press the throttle, it is most likely caused by a leaky carburetor or crankcase. This problem can be solved by checking and adjusting the carburetor for leaks.
It may also be caused by a faulty fuel tank breather. Because of the vacuum in the fuel tank while the chain saw is running, the correct volume of fuel mixture is not getting to the engine and it either doesn’t rev up or shuts down. If you stop the saw, open and close the fuel tank and restart it, it will work normally for about 5 minutes and then either stop working or choke again.
Another possible reason for a chainsaw not being able to reach revolutions may be excessive soot in the muffler, making it difficult for the exhaust gases to escape, which reduces the engine’s power and revs.
Evaluate the condition of the piston/cylinder group
Often the engine will not start or does not run at full power due to low cylinder pressure. It can be caused by wear of the piston or cylinder, retracted piston rings, worn bearings, etc. Remove the muffler and look at the opening for a partial view of the cylinder-piston group (CPG).
A compression gauge placed in the spark plug hole will help to measure the compression in the engine. the results of the measurement can also tell you about the condition of the cylinder head. It is only after a complete disassembly of the machine that accurate information can be obtained. If there are chips or scratches on the piston, it must be replaced. Piston ring must be clean, free of carbon deposits, and must be in the correct position.
Wear on the piston and connecting rod assembly is a serious condition. Compression results are used to indicate the condition of parts of the cylinder and connecting rod.
- Poor quality of component parts and whole assemblies;
- unskilled care;
- use of low-quality fuel and oil surrogates;
- rough handling.
Remoteness from service stations and high cost of provided repair services, forcing owners of failed tools to restore their functionality on their own.
This variant is possible only after the warranty period expires. The difficulty is that the traces of dismantling of separate units and assemblies noticed by service technicians may become the reason for refusal of free repair of more complex and expensive parts.
Why the chainsaw stops when you press the gas and does not start under load at idle
It is not uncommon for chainsaw owners to encounter chain saw breakdowns, and it does not matter what model of this kind of equipment, because the nature of the breakdowns is almost all the same. Well, here’s a chainsaw stalled and what next? Undoubtedly, you can take the equipment to specialized services, which will repair your “iron friend” for a certain fee. But as they say: why pay more?
After all, you can disassemble the tool yourself and repair it, because the breakage may be insignificant, and you will pay a lot for it at the service. But it is natural that in order to bring back to life a tool you need to know how to understand the causes of its failure and how to troubleshoot. So let’s learn! In this article you can find answers to questions about situations where the tool simply stops after directly pressing the gas. So, let’s proceed.
Problems, connected with malfunctioning of the fuel system
A chainsaw occasionally shuts down when idling is also due to a fault in the fuel line or an improper ratio of ingredients in the “fuel mixture” consisting of gasoline and oil.
Before each start-up of the cutting mechanism, it is necessary to visually inspect its units and assemblies, paying attention to possible defects of the housing surface, mechanical damage, leakages of working fluids. This should also be done for the fuel line of the saw, which is usually a rubber tube.
If the machine has been (especially for a long time) in a damp place and had to endure drastic fluctuations in air temperature, this tube may have simply cracked. Such a fuel line is not good for further use and should be replaced.
Another reason for the chainsaw to stop when idling is that the proportions of the ingredients used to make the “fuel mixture” are not correct. The proportions of petrol and oil in it should correspond exactly to the original instructions of the particular machine. If they are not observed, the engine will not be lubricated sufficiently, and the entire mechanism will persistently throttle.
The saw stops working when the RPM is increased
Filters often get clogged, especially when the chainsaw is operated almost daily. The air filter can be disconnected and washed under running warm water. Dry thoroughly before reinserting.
If the fuel hose does not come out of the carburettor after you disconnect it, it is clogged. It can be cleaned or replaced with a new one.
If you use the tool often, the gasoline pump can break down. Because every part has an expiration date. It should be replaced or sent to a service center.