A saw clutch, also known as a centrifugal clutch, is the most vital part of a cutting chainsaw tool. Like in any mechanical device, a clutch acts as a switch transferring power from the engine to the device, allowing it to shift.
The same goes for a chainsaw clutch that consists of metal plates held tightly together by springs.
Located between the engine and the sprocket, it keeps the chainsaw running smoothly.
If you want to know more about the inner workings of the centrifugal clutch and how to ensure it lasts longer, keep reading.
Components of a Chainsaw Clutch 
The chainsaw clutch assembly only needs a few parts. They include:
The Drive Shaft
The drive shaft connects with the engine, and the shoes or friction pads wrapped inside the springs. It turns with the shoes and the springs at low RPM (revolutions per minute), with the drum, sprocket, and chain staying idle.
The drum is the outer rim of the drive shaft and is connected to the chain sprocket for engaging the chain. At higher RPM, it turns with the drive shaft and the chain.
The shoes include mechanical arms made of metal pads wrapped in springs that connect with the drive shaft. At higher RPM, they fly out to touch the drum and help it engage the cutting machine.
How Does a Chainsaw Clutch Work?
If the gas saw has no clutch, the tool will turn as soon as you start the engine, which would be risky. But it enables the engine to run at a lower speed without engaging the cutting device.
The clutch automatically engages when the engine runs at high speed and disengages when it slows down. What happens actually is that when the engine spins at a higher rate, the shoes also turn faster.
Their inertia overcomes the spring force compressing them, and their mechanical arms fly outward ( due to the centrifugal force), connecting with the drum. This causes the drum to spin and engage the chain sprocket.
When the engine speed drops, the shoes are overcome by the spring’s inertia, forcing them to pull back and away from the drum. This causes a gap to appear between the inner and outer parts. The chain sprocket stops spinning, even when the internal components powered by the drive shaft are turning.
What Causes Chainsaw Clutch Failure?
There are many possible reasons for causing chainsaw clutch problems. But the primary one is the worn-out high-friction lining of clutch shoes. As you repeatedly use the cutting tool, the lining wears down, causing the clutch to slip. A thin lining also prevents the shoes from making contact with the drum, stopping the saw from cutting the wood.
Potential Signs of a Clutch Failure
If your cutting tool is not functioning properly at the correct RPM, it can be dangerous for you to continue operating it. Therefore, identifying potential signs of a clutch failure is crucial for you to fix it before it causes any incident. Here are some signs of a poor clutch function:
Chainsaw Keeps Slipping
One of the common signs of clutch failure is when the saw starts slipping while cutting. This happens mostly when the blade is no longer held tightly against the engine, causing the clutch to slip.
Chainsaw Stops Working
If your cutting tool stops working or is cutting unevenly, there is a problem with its clutch, and you either need to repair or replace it.
Chainsaw Produces Noise
While cutting, if your saw vibrates and makes noises, it shows a problem with its clutch. It’s normal for the saw to shake and make noises. But excessive vibration and grinding noises that don’t allow the cutting machine to work properly can signify a failing clutch.
How to Maintain a Chainsaw Clutch?
Lubricating the clutch regularly comes under chainsaw clutch essentials. As you repeatedly use the cutting machine, the clutch goes dry. To avoid the loss of friction that happens when it wears out, you must lubricate the drum bearings once a week. This will enhance the clutch’s performance and ensure that it lasts longer.
When to Replace a Saw Clutch?
If your chain clutch has worn out, you must do something more than just chainsaw clutch adjustment or repair. You’ll need to inspect which components need replacement. Here’s what you’ll need to replace in a clutch:
- If you see grooves, oil contamination, or heat discoloration on a flywheel, replace it.
- Change the throw-out bearing when you are fixing the clutch.
- Replace the pilot bushing near the crankshaft if the saw clutch is slipping.
Usually, it’s easier to perform a complete chainsaw clutch replacement than fix it, especially if it keeps malfunctioning even after a repair. First, remove the chain, bar, and spark plug to replace the clutch. Next, remove the sprocket, unscrew the clutch shoe, and replace all parts.
1. Can you run a chainsaw without a clutch?
You cannot run a saw without a clutch. If there is no clutch, this means the chain is connected directly to the sprocket and will keep running even if the 2-stroke engine is idle.
2. How do I know if my chainsaw clutch is worn out?
If your saw is slipping while cutting, has stopped working, or keeps running, this means its clutch is worn out. This happens when the high-friction layer on the clutch shoe wears out or due to the metal fatigue of the drum.
3. At what RPM does a chainsaw clutch engage?
Depending on the type and size of the saw engine you own, the RPM for engaging a clutch lies between 10,000 and 14,000. An electrically operated saw clutch usually engages at 2000 to 3000 RPMs, while a single-cylinder gas-operated clutch operates at 3600 to 4000 RPM.
4. What kind of clutch is on a chainsaw?
The saw clutch is also referred to as the centrifugal clutch. It uses centrifugal force to automatically engage and disengage the clutch for driving the cutting tool.
Final Takeaways: How Does a Chainsaw Clutch Work?
Hopefully, our above post has been able to answer your query regarding “how does a chainsaw clutch work?”. A clutch is a vital part of a saw and helps engage the tool when the engine runs at high speed.
It disengages the cutting machine when the engine is idle, ensuring there is no risk of the device running when you are not using it. However, the clutch can wear out when you use the chainsaw repeatedly.
To keep it in perfect condition and ensure it lasts longer, you’ll need to perform regular maintenance, like lubricating its components. Moreover, if you see any potential signs of clutch failure, it’s wise to replace its components to avoid the risk of any injury.
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