What Is A Chainsaw Compression Test?

The compression in a chainsaw is what converts fuel into potential energy to run the chainsaw. So, what is a chainsaw compression test?

A chainsaw compression test is conducted with a compression test gauge. This measures the level of compression the chainsaw produces. Every chainsaw requires a specific amount of compression. If production is more or less than required, the engine can’t perform properly and may end up shutting down.

Read on to find out more!

What a chainsaw compression test is

A chainsaw compression test measures the level of compression that your chainsaw produces when in use. There are multiple ways to measure the compression of a chainsaw, but the most accurate way is to use a chainsaw compression test gauge. This is a gauge that fastens and seals in the spark plug hole of your chainsaw. Then when you pull on the chainsaw starter rope, it will measure the compression being produced.

A chainsaw compression test using the compression test gauge measures the compression through PSI. Most chainsaw compression levels should sit around 110 PSI on a compression test gauge. By conducting a quick chainsaw compression test, you can see if the compression is dropping or increasing. Fluctuating compression levels can be causing other problems for your chainsaw. Without chainsaw compression tests, your chainsaw compression levels could be all over the place. This can end up damaging your chainsaw’s engine and resulting in you having to buy a whole new chainsaw.

What is the purpose of a chainsaw compression test?

Performing a chainsaw compression test should be part of your regular chainsaw maintenance routines. The compressed air, when released, in your chainsaw, helps push pistons to fire and the whole chainsaw to function with power. If you don’t regularly check your chainsaw compression while doing chainsaw maintenance, the compression levels could be affecting your chainsaw engine.

What is the purpose of a compression test?

A compression test is designed to test only the compression levels of your chainsaw. Every chainsaw has its own unique level of recommended compression PSI depending on the brand, manufacturer, and model. Any increase or decrease in compression can lead to a number of problems. Therefore, the purpose of a compression test is to find out whether compression is affecting your chainsaw’s ability to function.

Internal engines, like the one inside your chainsaw, use compression to function. Fuel pistons within the chainsaw’s engine mix gasoline and air and spray the mixture into the combustion chamber. Within the chamber, the mixture gets ignited and creates combustion that compresses the cylinders within the engine, powering the chainsaw. This is why compression is such an important factor for chainsaw functionality.  With the importance of good chainsaw compression, you need to know how to perform a chainsaw compression test.

Signs that you may need to check your chainsaw compression levels include:

  • Difficulty starting the chainsaw
  • Poor chainsaw performance
  • Miss fires when pulling the start rope
  • Chainsaw won’t start at all
  • An untidy finish
  • A hard-to-control chainsaw
  • Chainsaw kickback

What can you use for a chainsaw compression test?

The best tool to use for a chainsaw compression test is a chainsaw compression test gauge. These gauges are specifically designed to fit chainsaws, sealing over the spark plug hole. This is important to prevent air from affecting the compression test. When pulling on the starting rope after attaching the test gauge, a needle will flick to indicate the PSI of the chainsaw compression.

What is a good compression for a chainsaw?

There is also a chainsaw compression thumb test that you can conduct if you don’t have a compression test gauge. But you won’t get as accurate of a reading with this. It’s better to visit a gardening and construction tools centre to get a proper compression test done if you don’t have the tools.

What is a good compression for a chainsaw?

For most average-sized chainsaws a good compression reading should be around 110 PSI; for larger chainsaws, 160 PSI is better. But it’s important to note that every chainsaw is different depending on the brand and model. On top of this, the motor capacity and temperature will influence the best compression level for each chainsaw. You can check the recommended PSI for your particular chainsaw by reading the owner’s manual that comes this the chainsaw.

A smaller chainsaw will usually have a compression range of between 90 and 110 PSI. A bigger chainsaw will typically have a compression reading closer to 160 PSI. If you get readings too low for an average chainsaw, it might be an indication of a leak of some kind. The leak can be a simple fix, such as tightening a loose component or a little troublesome such as replacing a component. A reading of below 70 PSI indicates a bigger problem and you may have to consult with a professional. Either way, having too high or low chainsaw compression increases the safety risks when using your chainsaw.

How much compression does a 2-stroke chainsaw need?

How much compression does a 2-stroke chainsaw need to run?

It’s advisable that a 2-stroke chainsaw maintain a compression reading of between 110 to 130 PSI. A 2-stroke chainsaw works by driving a piston up & down. The initial piston stroke creates a vacuum at the bottom. This vacuum is what sucks fuel up to the top. The piston stroke after ignites the fuel and pushes exhaust from the top. 

The compressed air from the initial stroke creates a vacuum that pulls in the fuel. Without an appropriate amount of compression, the fuel can get sucked into the engine. As you can see, the compression needs to be ideal to ensure that the chainsaw functions properly. Luckily, you can easily check the compression of a 2-stroke chainsaw by using the compression test gauge we mentioned earlier!

Once you have conducted a chainsaw compression test once, it becomes really easy. You just need to make sure that the test gauge is sealed properly over the spark plug hole. Otherwise, you’re going to end up with incorrect PSI readings. This might lead you to adjust the chainsaw compression and actually make it worse! Then you could ruin your chainsaw engine and be in the market for a new chainsaw much sooner than you ever intended.

If you are looking to buy a new chainsaw, check out our chainsaws for sale! We sell a range of high-quality Husqvarna chainsaws for all your sawing needs! If you found this article helpful, we have a bunch of other useful gardening and construction tips in our Canberra Diamond Blade Suppliers resources!

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