Operating a chainsaw is dangerous, and you should know what you’re doing before working with one. However, operating a chainsaw that doesn’t run properly is even more dangerous, and it’s extremely important to adjust everything to work correctly.
The most common issue is having the ratio of gas and air in the mixture wrong, making the chainsaw’s performance worse. So how can you know if your chainsaw is running rich?
If your chainsaw is running rich, it means that the engine is taking in more fuel than it’s supposed to take in. In other words, the mixture has too much gas in it. It will cause the chainsaw to work at a higher rpm, making the engine overheat and flood.
On the other hand, if your chainsaw takes in too much air in the mixture, it’s said to be running lean. Most commonly, the problem lies in a dirty or malfunctioning carburetor. I’ll share everything you should know about what running rich or lean means, how you can check and adjust your chainsaw if it’s not running exactly as it should run.
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What Does Running Rich with a Chainsaw Mean?
If your chainsaw is running rich, it means the mixture combustion in the engine contains too much gas, meaning the gas-to-air ratio isn’t good. It will cause the chainsaw to run at a higher rpm and waste too much fuel. Also, it will overheat more easily while the performance of the chainsaw will be worse.
The chainsaw will get warm very quickly when running rich but might not cut wood as well as it normally would. If you don’t take care of it and fix the problem, running rich for too long can flood the engine, making the repair a lot more expensive and complicated.
There are many reasons why your chainsaw might be running rich. Most commonly, the carburetor is causing the problem either when it’s malfunctioning or when it’s dirty. Cleaning it with a carburetor cleaner fluid might be the best starting point before committing to any repairs.
However, if the engine ends up getting flooded, no cleaner can fix it instantly. It’s hard to fix a flooded engine and quite expensive because it can pull more problems. In most extreme cases, the entire engine needs to be replaced.
What Does Running Lean with a Chainsaw Mean?
Running rich is one side of the spectrum when it comes to poor mixture inside the engine. If your chainsaw takes in too much air, the mixture will be too light, causing your saw to run lean. It won’t flood the engine, but it can cause other problems and malfunctions if running like this for too long.
If your chainsaw is running lean, it will take a long time to return to idle once you rev it up at a high rpm. Idle means the chain isn’t spinning even though the engine is on. Also, the saw will work at a higher rpm than recommended, but it will have less cutting power due to the lack of gas in the mixture.
Again, the main problem that causes malfunctions such as this would be the carburetor. The reason behind it is the fact that the mixture gets created inside the carburetor to create perfect conditions for ignition. If the carburetor is dirty or malfunctioning or isn’t adjusted properly, it will create a bad gas-to-air ratio, making the chainsaw run rich or lean.
If you are unsure if your chainsaw is running rich, lean, or just right, there are ways to check it yourself without having to take the entire chainsaw apart or having too much knowledge about how everything inside the saw works.
How to Check if Your Chainsaw Is Running Rich or Lean?
There are some easy tricks you can use to check if your chainsaw is running rich or lean. What most people do is simply listen to how the motor is running. If you hear a smooth 4-stroke burble, you’re running properly. If you hear an odd clicking sound, or if the engine sounds louder than usual, there’s a chance you’re running rich or lean.
If you’re unsure how the engine is supposed to sound, try going full-throttle and releasing. If the chainsaw is low to get to idle, it probably works under higher rpm, which is a clear indicator that you’re running lean.
On the other hand, if your engine is too loud and you feel like the saw is overheating, you’re probably running rich. If you are still unsure, use a tachometer to see if your chainsaw runs close to the recommended rpm when going full-throttle. If not, then you’re running either rich on lean, meaning you need to make the proper adjustments.
Finally, there’s a spark plug on your chainsaw whose color under full-throttle indicates the state of your chainsaw. If it’s white or light-grey, your mixture is lean. Black color means you’re taking in too much gas (running rich). Aim for light brown to chocolate color for perfect performance.
How to Adjust Your Chainsaw if It’s Running Rich or Lean?
Now that you know how to detect problems with the mixture, it’s time to make the required adjustments to get your chainsaw working properly. First things first, make sure that your carburetor is clean. Small particles of varnish and dust tend to stick to the carburetor, making it run wrong.
Cleaning it properly will usually be enough, but sometimes, manual adjustments are needed as well. Usually, there are three adjustment screws you can use to get your chainsaw working right: the H and L screws on the carburetor and the T screw on the chainsaw itself.
Adjusting the H and L screws will determine how much gas or air is getting into the mixture, so you should turn them according to your needs (whether your saw is running lean or rich).
Finally, the T screw is used for idle-speed adjustment. Once you get the mixture right, you need to get the idle speed in the correct position. You’ll know when you got it right when the chain starts slightly moving as you turn the screw clockwise.
