Chainsaw Too Much Compression: Causes & Solution

Have you felt any difficulty in pulling the chainsaw cords? If yes, then this article is for you. We will explain the causes of high compression and how you can quickly fix it to make it run smoothly.

Before getting dive into our topic, let’s define a chainsaw. A chainsaw is an electrical, battery-powered instrument with rolling cords to cut woods, etc. Depending on your work, there are different chainsaw versions, but the standard function is the same in all these machines.

So, If you are feeling too much compression while pulling a chainsaw, then the possible reasons might be

A chainsaw is a relatively more powerful and heavy-duty saw than the ordinary one. It uses gas, electricity or battery as a fuel. It is designed with tooth along the chain that is attached to the perimeter of a steel blade. An engine is fit on the rear side of it. The engine creates a vacuums pressure inside it, this compression converts fuel (any source) into the potential energy in engine to start it. If the compression is not produced in the engine at an appropriate level, it will not be able to convert fuel into energy.

Every chainsaw requires a specific amount of compression, if this compression is more or less than the required amount than engine will not be able to produce energy from fuel source and it will be exhausted faster. A compression gauge is used to measure the compression of a chainsaw which works similar to the tire gauge.

Every chainsaw requires different compression level according to its built up and model number. A heavy-duty chainsaw requires a large amount of compression whereas as a chainsaw with smaller engine needs less compression to convert fuel into energy.

If a chainsaw has a 2 stroke engine, then the maximum compression it requires is 110-130 PSI. Similarly a 4 stroke engine needs 2 times more compression than the 2 stroke engine that is around 180-210 PSI.

Now how much compression does the engine of a chainsaw needs depend upon the capacity of its motor and temperature. This could be understood by reading further explanation below.

Capacity Of The Engine:

The power of motor of an engine is measured in its capacity. Every chainsaw engine has different capacity depending upon its motor power. A large engine has a huge capacity in its motor. It is obvious that the motor which has huge capacity will require more compression. The chainsaw motor engine capacity can range from 30CC and 50CC to 150 CC.

A 50CC engine needs 150 PSI compression. If the engine capacity is 100 CC the compression limit should also be doubled.

Temperature Of The Engine:

A heavy-duty engine gets hot faster and it works better than the cold engine. A hot engine also requires more compression to convert furl into energy as compared to the colder one.

A cold engine will need the compression of 50-100 PSI whereas a hot engine will require compression above 150 PSI.

Too much hot or cold engine does not work or even start to produce vacuum pressure inside engine. Therefore, it does not need any compression rate to start.

Without proper compression, the engine will not be able to suck and use the fuel for combustion. Finally the fuel will be converted into energy. A highly compressed engine will not be able to work smoothly because of the too much pressure on engine and you will find it hard to start the engine.

Likewise, low compression in the engine will be slow and retarding and it is a warning sign of leakage in your engine. In this case fixing or repairing is required or worst replacing the engine all at once.

The Starter Housing:

Most of the time, the chainsaw cord became hard to pull because of the Starter Housing. The Housing is the outer cover of the starter, and if it is damaged, your chainsaw suffers stiffness during a pull.

There might be a small stone or thing that is stuck inside the starter and causes the rope not to retract.

It is a prevalent issue and can be fixed and detected easily without consulting a mechanic.

You have an option to either pull off the starter and clean it or look for an ideal replacement for your starter house.

Damaged Pulley compartment:

The Pulley compartment plays a massive role in retracting the ignition rope. While rope attached to a pulley, the further connection of the pulley is with springs and pawl to make sure the pulley is tensioned and helps in retracting and spinning.

If there is any damage to the pulley at any stage, it will cause “High Compression” or “stiffness during a pull.”

You can also quickly fix this anomaly by ensuring a proper troubleshooting of the pulley compartment to find damages. Once you identify the cause of high compression, you can repair that affected part or find a new replacement for it to make it work smoothly.

Stucked ignition rope

The other cause of your chainsaw’s high compression could be the stuck ignition rope. The starter assembly often fails to rotate due to a weak connection between the pulley and the ignition rope. Your ignition rope must be intact properly with the pulley to work correctly. Sometimes, the ignition rope is frayed or stuck inside the starter housing. Usually, this happens when you use a chainsaw after a very long time or by wear and tear of the rope. Keep in mind that the stuck ignition rope can also damaged other parts inside the starter assembly. So, replacing the ignition rope is a better option to keep everything working smoothly without any damage.

Lack of Oil:

Another big issue that causes too much high compression is the lack of oil in the starter system. The lack of oil dried the chainsaw assembly, which causes high compression and becomes very difficult for you to handle the chainsaw.

The other reason might be the use of the wrong type of oil for the climate. If you are trying to start your chainsaw in winters and the oil you used for the chainsaw assembly is not suitable for the winter season, you also feel high compression. This is because your oil is not rated to get to work at a low temperature.

Overuse Starter Spring:

As the starter, spring plays a vital role in running starter assembly smoothly. If the starter spring is keep working correctly, it will retract the ignition rope. Sometimes the spring stops working correctly due to overuse and becomes brittle.

If you regularly use the chainsaw, then there might be the possibility that your starter spring breaks off.

So, in our suggestion, one of the first things to check while feeling high compression is the starter spring.

It is effortless to check the starter spring; pull the ignition rope. If it is hard to pull, then check how the spring is performing. If you see any unusual movement of spring, then take it in to replace it.

If you do not replace the starter spring on time, it will cause you to replace the whole starter assembly.

I hope you understand the problems why your chainsaw is hard to pull. We describe all the possible issues and also suggest the solutions to fix them too.

If you still have questions regarding high chainsaw compression, you can discuss them in the comments.

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