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Chainsaw Leaking Oil. Tips from a Professional

A chainsaw requires timely lubrication of the bar and chain as part of its periodic maintenance. It is not rare for chainsaws to leave oil stains at the place they’re kept. However, if the oil is leaked in a considerable amount and continues to do over a prolonged period, this should be a concern. This article will investigate the causes behind a chainsaw leaking oil and how it could be fixed.

Chainsaw leaking oil

Your chainsaw could be leaking oil due to the following reasons:

  • Poorly vented oil tank: This can increase the air pressure within the tank and cause oil to seep out of it.
  • A missing stud from the oil tank
  • Overfilled oil tank
  • Ruptured oil line

Besides these above reasons, the oiler’s adjustment screw set too high could also give the impression of an oil leak.

In the following sections, I shall comprehensively elaborate on the factors mentioned above that cause chainsaw oil leakage.

Why does my Chainsaw Leak Bar Oil when not in Use?

If a chainsaw leaks oil when turned off, the chances are that the oil tank might be overfilled or poorly ventilated. The pressure buildup within the tank causes some oil to flow out of the tank. Punctures in the oil lines could also cause oil to leak when the chainsaw is not in use.

A chainsaw that spills oil is never a good indication. It will not only make a mess, but it may also degrade the chainsaw’s performance. You may need to put oil in your chainsaw regularly. Let’s take a look at some of the most prevalent reasons why a chainsaw could leak bar oil when not in use.

● Reason 1 Chainsaw Leak Bar Oil: Poorly Vented Oil Tank

One of the least sought-after causes that could result in oil leakage. Chainsaw oil tanks should be ventilated to avoid the formation of a vacuum. Furthermore, the air pressure between the tank and the atmosphere should be equalized. Most tanks include a one-way valve that enables air to flow into the tank to keep the air pressure constant. When the temperature varies substantially, the air pressure inside the tank fluctuates.

For example, the air pressure in the tank drops at night owing to a temperature reduction. This allows air to enter the tank and equalize the pressure. During the day, as the temperature rises, so does the air pressure. Because the valve is just one way, air cannot flow out of the tank; hence, the only way to balance the pressure is to drip some oil from the ports. This phenomenon is more prevalent in areas that encounter significant temperature changes.

– Fix:

Fixing this issue is relatively easy. To adjust the air pressure inside the tank, loosen the oil reservoir’s cap by a small amount. No oil would be forced to flow out of the ports now that the pressure has been equalized. Tighten the cap on your oil tank after you’ve made this change. This simple technique is recommended whenever you start your chainsaw on a hot day after letting it sit all night.

● Reason 2 Chainsaw Leak Bar Oil: Missing Stud

In most chainsaws, a stud is visible from the muffler’s side at the bottom of the oil tank. If the stud is missing from its position, there will likely be leakage. It is relatively small (approximately 0.1 inches in diameter) and is likely to become misplaced. To check for this, use a flashlight to look from the muffler’s side and see if you can notice the stud or if a hole is apparent.

– Fix:

To acquire the stud from a local dealer, you will need to know its part number. Look through the owner’s manual to see if you can find the part number. If not, a similar-sized stud can be found at any hardware store. Just make sure the item has the same diameter as the hole and isn’t too long.

● Reason 3 Chainsaw Leak Bar Oil: Overfilled Oil

According to many chainsaw users, overfilled oil is the most frequently reported cause of over-oiling. When the oil tank is overfilled, there is always the chance of oil seeping into the sprocket and chain, giving the appearance of a leak. This is quite common in environments with considerable temperature changes. When the temperature suddenly rises, the already overfilled oil may expand and seep into sections of the sprocket and guide bar assembly.

This phenomenon of overfilling also applies to engine oil and fuel. If the tank’s oil-fuel mixture (also known as premix) is overfilled, there is a good probability of seepage.

– Fix:

Just make sure you haven’t overfilled the bar oil reservoir or the fuel tank with an oil mixture. Even if it were overfilled, the extra oil would have been expelled by the chainsaw, and it should not leak any more oil.

● Reason 4 Chainsaw Leak Bar Oil: Oil line leak

The oil line transports the bar oil from the tank to the oil pump. The tube may be punctured, causing some oil to spill from it. Tilt your chainsaw over and remove the lower cover to see if the line is faulty. If there is a significant amount of oil buildup in that area, it is most likely due to a ruptured oil line.

– Fix:

Before reinstating the oil line, ensure that the oil reservoir has been emptied. To obtain access to the line, unscrew the engine mounting nuts and bolts (if applicable). Use a flat head screwdriver to pry it out of the holes. Replace it with a new oil line and reconnect everything that was removed.

Why does Oil Leak from my Stihl Chainsaw?

If the oil tank isn’t correctly ventilated or if the stud that secures the port is misplaced, a chainsaw could leak oil. Another possible cause of the problem is an overfilled tank. Most of the time, a huge amount of oil beside a chainsaw isn’t the result of a leak.

When they notice a substantial amount of oil around their Stihl chainsaw, most new users become alarmed. Based on my experience with Stihl chainsaws, I can guarantee that seeing this oil spread is relatively common. It is typical for a chainsaw to leave oil behind, especially after cutting.

Most new Stihl chainsaws spray a tiny mist of oil off the chain onto the guide bar.When these droplets accumulate, they run down the guide bar, raising the possibility of an oil leak. Furthermore, the clutch, the groove in the bar, and the sprocket all expel oil droplets that collect while cutting. Please keep in mind that it is not a leak.

To keep this oil from making a mess, I recommend storing your chainsaw on dry cardboard whenever possible. Oil leaks are distinguished by a continuous flow of oil across your equipment. Furthermore, in the event of a leak, you may frequently replenish the oil in your reservoir. When you determine a leak, you should proceed with the troubleshooting methods outlined further in this article.

● Identifying an Oil Leak:

Store your chainsaw in a dry spot for a few hours to assess whether the oil puddles are the result of a leak or a normal throw-off from the chainsaw. Make sure it’s clean of any oil residues before storing it, and take note of the oil level in the tank. If you notice a drop in the oil level in the tank after some time, as well as puddles of oil around the device, it’s a sure sign of a leak.

An alternate strategy can be used to save time. Place a piece of paper in front of your chainsaw and run it for a few minutes with the guide bar directly above the paper. Small oil droplets on the paper result from regular oil throw-off from the chain. However, if the paper becomes drenched with oil, it becomes a problem.

One tank of bar oil is typically used for every tank of fuel. However, if there is a leak, the oil consumption goes way up. You may need to inject oil more than once or per gasoline unit.

● Adjusting the Oiler:

If the leak point hasn’t been identified and the oil leakage is considerable, the oiler mechanism needs adjustment. The oil adjustment knob is located beneath the chainsaw, and the adjustment screw controls the oil flow to the oil pump.

Most chainsaws feature a notation on the screw (represented by a plus and minus sign) that tells us which way the screw must be turned. Turning the screw in a plus direction increases the oil flow, and turning it in the minus direction does the opposite. In most cases, the oiler is set at max setting, due to which the oil consumption increases dramatically and gives an indication of possible leakage.

How do I Stop my Chainsaw Oil from Leaking?

To stop your chainsaw oil from leaking, ensure the oil lines aren’t punctured. Avoid overfilling your oil tank, and always keep it thoroughly vented. Make sure the oil outlets aren’t plugged with sawdust.

Once you’ve checked that the oil puddles aren’t due to regular operation and the oiler setting is set correctly, your chainsaw is probably leaking oil. There can be more than one reason behind this. Let’s look at developing an effective strategy to counter these and prevent oil leakage from your chainsaw.

● Stop a Chainsaw Oil from Leaking 1: Refurbish the Oil Lines

Your oil delivery mechanism may have encountered a fault. The oiler mechanism consists of the oil reservoir connected to an oil pump. The pump which is connected to the throttle delivers the oil to the outlets via an oil line. In the event of a leak, check if the oil line is ruptured. Also, examine the pump and tank connections. Check and replace the seals at the connections if they seem worn out.

● Stop a Chainsaw Oil from Leaking 2: Avoid Overfilling

In most instances, overfilling your tank causes additional oil to drip off the guide bar and imitate a leak. Make sure your tank isn’t filled and the oil level is about half an inch short of the brim to prevent this. Also, ensure that the tank is vented as this prevents pressure buildup within, which could cause some oil to drip out, as explained in the above sections.

● Stop a Chainsaw Oil from Leaking 3: Keep the Outlets Clean

Oil outlets at the sprocket and the guide bar should be thoroughly cleaned. These outlets are prone to get clogged with sawdust after continuous use. Due to the blockage, the oil cannot flow out and exerts back pressure at the oil pump and the reservoir. Consequently, it may tend to form a leakage from those points. Use a thin metal wire to dislodge debris and sawdust deposits to clean the outlets.

Do Electric Chainsaws Leak Oil?

An electric chainsaw may also leak oil despite its different technology than a gas chainsaw. The causes of oil leakages are quite the same as discussed for gas-powered chainsaws.

The electric chainsaws may leak oil if they are overfilled. Hence, you would need to siphon out some oil to solve the issue. If the oil pump is dusty, the electric chain saw may continue to leak oil even after you have extracted it from the reservoir. Excessive oil on the oil pump gaskets might lead to leaks. Clean the gaskets and inspect them for wear. Replace the gaskets if they are ruptured.

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