I want to discuss the benefits of using a chainsaw equipped with a decompression valve. As someone who frequently uses chainsaws for yardwork and woodcutting, I’ve found that models with decompression valves offer noticeable advantages over saws without them.
In this post, I’ll explain what a decompression valve is, outline the main benefits, describe how the valves work, list some chainsaw models that have them, advise when to use the valve, and more. My goal is to demonstrate why a decompression valve can be a valuable feature on a chainsaw.
What are the benefits of using a chainsaw with a decompression valve?
There are several key benefits to using a chainsaw equipped with a decompression valve:
The decompression valve releases some compression from the combustion chamber during the starting procedure. This makes the engine easier to turn over when pulling the recoil starter rope. Without a decompression valve, the compression in the chamber makes the chainsaw more difficult and strenuous to start, especially when cold. The decompression valve gives you an easier time kicking over the engine on the first few pulls.
Reduced wear and tear on the pull starter
Because you don’t have to pull the starter cord with as much force thanks to the decompression valve, there is less strain and wear on the pull starter components. Yanking on the starter rope excessively to overcome high compression can damage the recoil and other starting mechanisms over time. A decompression valve allows for an easier, gentler starting procedure that preserves the pull starter.
Hard starting due to high compression pressure can lead to hand and arm injuries. Having to strain yourself to pull the starter cord many times puts unnecessary stress on muscles and joints. The reduced effort needed to start a chainsaw with a decompression valve decreases the risk of these types of painful injuries. Safety should always be the number one priority when operating power tools like chainsaws, so features that prevent injuries are hugely beneficial.
How does a decompression valve work?
There are two main types of decompression valves used on chainsaws:
Manual decompression valve
A manual decompression valve must be activated by the user before starting the chainsaw. There is typically a rubber button or lever that you press or flip to open the valve. This releases some compression from the cylinder. The valve then resets to a closed state once the engine starts up. You need to manually open the valve each time you go to restart the chainsaw.
Automatic decompression valve
An automatic decompression valve operates without any input needed from the user. When the chainsaw engine isn’t running, the valve automatically opens to bleed off some compression. As soon as the engine starts, the valve immediately closes and remains closed while the saw is running. This type of decompression valve is more convenient since you don’t have to remember to activate it manually.
Chainsaw models with decompression valves
Many chainsaw brands now include decompression valves on some or all of their models:
Stihl MS260 Pro
One of Stihl’s most popular pro-grade chainsaws, the MS260, features a decompression valve for significantly easier starting. This makes the saw much more user-friendly while still delivering excellent power.
Several Husqvarna chainsaw models across the brand’s product range come equipped with decompression valves. This includes the mid-level 450 Rancher and high-performance 372XP saws, which are easier to start thanks to the decompression system.
When to use the decompression valve
The main time you’ll want to utilize the decompression valve on your chainsaw is when starting a cold engine. Other situations when decompressing the cylinder can help are:
Starting a cold engine
Be sure to activate the decompression valve when starting a chainsaw that has been sitting. The compression in a cold engine is at its highest, so the decompression valve makes a big difference in being able to turn over the motor with the pull cord. After starting, the valve can reset.
Starting a hot engine
You may or may not need to use the decompression valve when restarting a hot chainsaw right after use. The compression will be lower in a warm engine, so sometimes the decompression isn’t necessary. But activating the valve can still make starting a hot saw a bit easier.
Decompression valve maintenance and potential issues
While very useful, decompression valves can have some drawbacks if not properly maintained or used correctly:
Some chainsaw owners worry about potential leakage from the decompression valve that could impact performance. However, most valve systems are designed not to leak under normal operating conditions.
Plugging the decompression valve
To eke out a little more power, some users will plug the decompression valve port. This eliminates any small power losses. However, this makes starting the saw much more difficult and is not recommended. Make sure the decompression system is kept in good working order.
Proper maintenance and operation will prevent most issues with the decompression valve. Be sure to follow the manufacturer’s recommendations for inspection intervals and replacement of worn parts.
Chainsaws equipped with a decompression valve offer noticeable benefits in terms of easier starting, reduced starter wear, and improved safety. The valve bleeds off cylinder compression to allow for an easier pull on the starter cord when firing up a cold saw. This helps prevent hand injuries and damage to the starting mechanism. While not found on every chainsaw, decompression valves are worthwhile features to look for when choosing a new model. With proper maintenance, they can provide reliable service and make your chainsawing experience much more user-friendly.
Frequently Asked Questions
How do I know if my chainsaw has a decompression valve?
Not all chainsaws have a decompression valve, so check your owner’s manual or contact the manufacturer if you are unsure. On saws with a manual valve, you will see a rubber button or lever to activate it. Automatic valves are not externally visible but will be listed as a feature.
Can I add a decompression valve to my chainsaw if it doesn’t have one?
You may be able to retrofit a decompression valve, but you would need to consult the manufacturer or a qualified technician for specific advice. Certain saw models are not designed to accommodate decompression valves.
Is a decompression valve necessary for smaller chainsaws?
On smaller, lower powered chainsaws the lower cylinder compression doesn’t necessitate a decompression valve for easy starting. But they can still be beneficial even on compact saws.
Can a decompression valve affect the power of my chainsaw?
An improperly sealing or damaged decompression valve that is leaking compression could potentially lower power output. Proper maintenance and operation helps prevent power loss.
What are the signs of a malfunctioning decompression valve?
Difficulty starting, decreased power, or rapid wear of the starter mechanism can signal issues with a leaky or plugged decompression valve. Have your saw serviced promptly to avoid further damage if symptoms appear.
How do I maintain my chainsaw’s decompression valve?
Check valve operation regularly when cleaning the saw. Inspect for signs of leakage, blockage, or stuck components. Follow the manufacturer’s valve service intervals and replace worn parts when needed.
Are there any alternatives to using a decompression valve for easier starting?
Some chainsaw models feature spring-assisted starting or reduced kickback starter handles to help reduce starting effort, but a decompression valve is still the most effective method.
Michael Boyle is the founder and main author of Chainsaws Finder, boasting over 20 years of experience in the chainsaw industry. Hailing from Texas, Michael combines his extensive knowledge and hands-on expertise to provide reliable advice and top-notch service. His vision is to empower chainsaw users to tackle any project with confidence, making Chainsaws Finder a trusted resource in the field.