How to Clean A Chainsaw

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How to Clean A Chainsaw, the easy way. And why it matters? I know many people who never even think of cleaning their chainsaws but as you’ll learn in this article, it’s a good idea to keep your chainsaw clean. Dirt, dust and oil can build-up and eventually effect the functioning of your chainsaw. Especially if you work in harsh conditions, you should clean your chainsaw on a regular basis.

Before we start talking about the tools needed and the process of cleaning your chainsaw, let us first explain some of the issues that prevent a dirty chainsaw from running properly. A chainsaw is an extremely simple machine on the surface, but there is plenty of stuff going on underneath which cannot be seen until you remove the covers and take the whole thing apart. Whenever a cutting tooth on the saw chain digs into wood, it carves out small chips of material along with tiny powder- like specks of sawdust. The momentum of the moving chain carries these particles into the groove of the bar upon which the chain rides.

Some of the sawdust and wooden chips also get flung into the spaces in-between each chain link, combining with moisture and bar oil to form a semi- solid and highly sticky substance that soaks up new bar oil and prevents it from lubricating the chain. This will cause your chain to run hot, and it will also scrape against the bar rails more often causing the formation of a burr on either edge of the bar. Now, not only is the chain running hot and causing more friction, but it is also bouncing off the uneven edge on the bar which will prevent you from cutting straight and increase vibrations. A chain that isn’t lubricated will fail sooner, and the last thing you want is sharp metal links flying into your face at 60mph.

Sap, sawdust, grease, and other unwanted substances will also accumulate underneath the clutch cover on the side of the chainsaw. This will eventually clog the oiler holes from which bar oil is secreted into the bar of your chainsaw and can harm performance as well as reliability of the parts. If too much gunk collects around the chain brake mechanism, it can cause the inertial brake to slip and you may not be able to stop the saw in case of an emergency. Sawdust and dirt are also sucked in through the other side of the chainsaw, via the grill underneath the starter rope. This grill sucks in air to cool the engine and it also sucks in debris that is ejected when you cut wood.

Sawdust and wooden chips can accumulate in between the cooling fins on the cylinder head, restricting airflow and reducing cooling performance. As a result, the engine will run hotter than usual and this may eventually result in damage to the internals of the motor (piston, cylinder, etc.). The air filter is what allows your chainsaw engine to “breath”, and when it is clogged the carburetor isn’t going to get sufficient air and this will affect engine performance at higher RPMs. If the air filter is extremely dirty, you may not even be able to start the chainsaw.

You will also need to inspect the spark plug for carbon accumulation, because a dysfunctional spark plug will result in incomplete combustion of the fuel/ air mixture and loss of power. A faulty spark plug may also mean that the engine won’t start. Stihl recommends that you replace the old spark plug with a new one every 100 service hours. There are different types of spark plugs, check the owner’s manual to make sure you are replacing the old one with a proper model.

VIDEO | How to Clean your Chainsaw

Table of Contents...

1 How to Clean A Chainsaw

Tools you will need to clean a chainsaw

Wire brush (here is a nice set)
1” or 2” paint brush (like this Wooster Q3108-1 soft tip brush)
Grease gun (simple push-type will suffice)
WD40 spray (serves as a lubricant and degreaser)
Universal cleaner of some kind (like Simple Green Pro HD )
Flat hand file
Bar groove cleaning tool (putty knife or a folded business card also works, pretty much anything that is flat and fits in between the bar grooves)
Pick to clean oiler hole (you can also use a small flathead screwdriver)
Scrench
Warm water

Optional:

Note: You don’t need all the tools that we have mentioned in this list, the optional category is mainly for readers who own multiple chainsaws and need to clean 4 or 5 of them together. Unless you are a professional logger, workshop owner, or DIYer, you won’t need a pressure washer or shop vacuum. But if you happen to own a workshop, you probably have the aforementioned tools which are going to make your chainsaw cleaning experience much more convenient. And you might not need the universal cleaner fluid either, many experienced chainsaw users use simple household ammonia solution or kerosene to clean their grimy chainsaw bars and chains. On the field for quick cleanups between cutting sessions, all you need is a scrench and a brush.

Step 1

Removing the bar and chain

In order to clean the various parts of a chainsaw, we must first take it apart to gain easier access. For this, you need some kind of flat and stable surface. A workbench or table of some kind would be perfect, and make sure to keep all the tools nearby. If you’re cleaning an electric chainsaw make sure it is disconnected from the power source, and if it is a cordless chainsaw take out the battery before you start cleaning. For gas chainsaws, drain all fluids (gas and bar oil) before you start cleaning. Now, located the two nuts on the side cover which keep your bar mounted to the powerhead. Loosen these nuts from the bar studs using the hexagonal wrench part of the scrench, and make sure that the anti- kickback chain brake is disengaged before you remove the clutch cover. On some chainsaw models you cannot remove the cover while the brake is engaged, on others you might be able to remove the cover but putting it back on will be impossible.

Step 2

Cleaning the bar

After the bar and chain have been separated from the powerhead, take out the chain and put it aside. Depending on how dirty the bar is, you might need to use a degreaser or solvent of some sort. If it has been used to cut down a couple trees over the weekend, you should be able to get all the dirt and grime off with some warm soapy water and a cloth rag. Take the wire brush and scrape away all the sawdust and hardened dirt from the bar. Using the bar groove cleaner tool or a putty knife, clear out all the gunk that is stuck within the bar rails.

Once the groove of the bar is clean, take a pick or screwdriver and get rid of all the debris blocking the oiler hole. There are two oiler holes on each bar, one on either side of the bottom end (the end that connects to the powerhead). If you have an air compressor, you can use it to blow away any stubborn debris. Steam at around 300°F also works great, if you happen to have a steam cleaner in the workshop.

Hot soap water works just fine for chainsaws that are used occasionally on weekends to cut some firewood. But what if you’re a professional who uses the chainsaw daily for felling trees in the woods or cutting branches 80 feet above the ground? Compressed air and high pressure steam are the perfect choice to clean the dirtiest of chainsaw guide bars. But since most of you don’t own a steam cleaner or air compressor, there is a neat little trick to getting rid of pitch and dried up resin from your chainsaw bar. We are going to use Simple Green Pro HD Heavy Duty cleaner. This is a non- corrosive, biodegradable, multipurpose cleaner which acts as a solvent and degreaser to remove all the grime and dirt.

Mix the concentrate in a 1:3 ratio with water and fill up a bucket with the solution. Then dip the bar into the bucket, along with the clutch cover. Let it soak for about 10 minutes and use the wire brush to scrape away the dirt. Dry the bar, then give it a light coat of the WD40 spray and leave it to set for about half an hour or so, then wipe it off with a rag.

The bar is almost ready for installation in the chainsaw, just check the edges to make sure there is no mushrooming going on around the rails. Run your fingernails over the edge of the bar rail and if your nails click on a sharp metal burr extruding out of the rail, it is time to take the hand file and make a few passes on the bar. This will ensure that the bar edges are smooth and flat, so the chain can ride without issues. A great tool for removing burrs and uneven edges from the guide bar is this redresser tool, it will reset the rails to a 90° angle and remove all burrs at the same time.

VIDEO | Basic Chainsaw Maintenance

Step 3

Cleaning the chain

To clean the chain, soak it in some turpentine or a solution of household ammonia and water (for 10 to 20 mins). This should get all the grease and resins out from within the links of the chain, and dissolve most of the caked up sawdust. Now take the wire brush and scrape it clean. When working with an ammonia solution, it is crucial that you stay in a well- ventilated area and prevent contact with skin or eyes. Use gloves and eye protection. If the chain isn’t too dirty, you can simply scrape off the dirt with a brush and wipe it clean with a rag. Now there is another method of cleaning the chain if it is absolutely engulfed in pith and caked up sawdust, but we only recommend this if you are experienced with tools or if you are a professional logger (no other way your chainsaw would get that dirty).

Take some household lye, used to open up drains. Pour out some pellets onto the cap of the container and mix it with about half a bucket of water. Wear thick gloves and eye protection, do not let these pellets come in contact with your skin. Put the chain in the solution and let it soak for about 20 minutes or longer depending on how dirty it is. Don’t let it sit in there overnight though, since the chain will start to rust. After it is soaked, pull out the chain with a hooked tool of some kind, DO NOT use your hands to remove the chain from the solution even if you are wearing gloves. Throw it on the ground outside, let all the excess solution run off and hose it down thoroughly with water. Once it is dry, take the chain back inside and wipe it clean with multiple paper towels until all the dirt is gone.

Important: make sure to dip your freshly cleaned chain in some bar oil and wipe off the excess oil before you put it in storage. This way, it won’t rust. Also coat it with bar oil before reassembly with the guide bar.

Step 4

Cleaning the powerhead

To clean the powerhead, use a 1” soft tip paint brush and remove all the dirt that has settled down around the crankcase area. Use the pick or scrench to access tight spots, and gradually scrape away every bit of sawdust around the clutch drum and bar studs. Make sure that the oiler port is free of debris. You can also use compressed air to clean the powerhead, but we don’t recommend a pressure washer as it can damage the air filter and electronic systems if you aren’t very careful.

Remove the top cover and you should be able to access both the air filter as well as spark plug. Inspect the air filter, if it is covered with light to moderate amount of dust take a soft tip paintbrush and gently clean the filter medium. It is extremely important that you stuff the air intake of the carburetor with a clean rag to prevent foreign objects from falling inside. Or, you can set the choke to “closed” position to seal the carburetor from the inside.

You can also use compressed air, but make sure the compressor is set for low pressure, so you don’t blow a hole in the air filter. Stihl recommends a non-inflammable, non oil based cleaner if you want to rinse the air filter under running water. If the air filter is really dirty, take some warm soap water and clean it from the inside out (water flows from clean side of filter to dirty side). After using the soap solution, rinse the filter with some clean water and let it dry completely before you reattach it.

Inspect the spaces between the cooling fins on the cylinder head and use a screwdriver or the bar cleaner tool (preferably something made from a soft metal) to clean out all the gunk from between the cooling fins. This will improve engine cooling and increase its lifespan. Also remember to take out the grill cover for the starter rope and brush away all the sawdust that is accumulated around the crankcase.

Finally, remove the spark plug and inspect it for signs of degradation. If the electrodes are a coffee brown color everything should be fine. Check the gap between the electrodes to see if it is too large or small, incorrect gap size will prevent the spark plug from working properly. If the tip appears dark black or is covered with baked-on dirt, it might be time for a replacement. Refer to your owner’s manual for the correct replacement part no., and make sure to check the gap between electrodes since some spark plugs may not be gapped from the factory. Stihl recommends a gap of 0.02 inches or 0.5mm for its NGK CMR6H and Bosch USR4AC spark plugs.

Step 5

Putting it all back together

Reattach the engine cover, starter cord cover and remount the dried up chain to the bar. Make sure the chain is mounted in the CORRECT direction. Now mount the bar back on the studs, connect the clutch cover and hand tighten the nuts. Hold up the bar by the tip of its nose and adjust the tensioning screw such that the segment of chain on the bottom side of the bar isn’t sagging (you should not over tighten it, just enough for it to move freely). Once the chain is properly mounted, take the scrench and tighten the bar nuts. Now your chainsaw is ready to cut wood, just refill it with gas and bar oil.