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8 Reasons Your SENIX Chainsaw is Smoking (Chain & Exhaust)

When trying to determine the reason your chainsaw has started to smoke, you’ll need to identify whether the smoke is coming from the bar or from the exhaust. Stop running your saw so you don’t cause additional problems and damage.

A SENIX chainsaw is smoking due to increased friction between the bar and chain because of a dull chain, a tight chain, a clogged oiler, or insufficient bar and chain oil.

The wrong engine oil level, water in the fuel system, or a plugged air filter may also cause a mower chainsaw to begin smoking

This is Why a Chainsaw is Smoking:

  1. Dull or incorrectly sharpened chain
  2. Chain is too tight
  3. Empty bar and chain oil tank
  4. Wrong type of bar and chain oil
  5. Clogged oiler
  6. Plugged air filter
  7. Low engine oil or too much engine oil in the crankcase
  8. Water in the fuel mixture

Take caution when troubleshooting and repairing your chainsaw. Shut off the chainsaw, wait for the engine to cool, and remove the spark plug boot.

Smoke coming from a SENIX chainsaw

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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

SENIX Chainsaw Smoking from the Bar & Chain

If you notice your chainsaw begins smoking when applying pressure to the bar while cutting, begin looking for items that can increase friction between the bar and chain.

This may be due to a dull chain, poor lubrication, or a chain that won’t move freely around the bar.

Dull Chain or Incorrectly Sharpened Chain

Not only will a dull chain provide you with a poor cutting experience, but it may also cause your saw to smoke.

A dull chain requires you to apply more pressure on the bar when cutting wood. This extra pressure results in metal-on-metal friction creating heat and smoke.

Look for these signs indicating the chain is dull:

  • Needing to apply increased pressure on the bar to make a cut.
  • Fine sawdust is created when making a cut.
  • Chips or damage to the chain.
  • Worn teeth and rakers.

You can sharpen the chains yourself. If you don’t have experience sharpening chains, I highly recommend having a professional sharpen them for you. A chain that isn’t sharpened right can be a serious safety hazard.

Lack of Bar & Chain Oil

Friction will build when your chainsaw isn’t getting enough oil to the bar and chain. This could be due to running out of oil in the tank or having a clogged oiler.

Fill the bar and chain oil tank if it is low on oil or empty.

To check for sufficient oil on the bar, run your chainsaw at about 1/2-3/4 throttle. Hold the bar 8-12 inches off the ground. You should see a line of oil coming off the bar and onto the ground.

If you aren’t getting good lubrication, make sure the bar is in good condition and the oil channel isn’t blocked. Replace a worn or damaged guide bar and clean the oil channel if needed.

It is good to get into the habit of refilling the bar and chain oil everything you fill your chainsaw with fuel. However, if the oil you are running in the saw is too thin, you may go through oil at a faster rate and have to check and refill it more often.

Wrong Type of Bar and Chain Oil

Using a bar and chain oil that is too thin may cause bar and chain damage and increased friction causing smoke to come from the bar. An oil that is too thin may not stick to the bar and chain and instead get slung off of it.

Make sure you are using a premium bar and chain oil like this oil from Husqvarna.

Chain is Too Tight

The chain will loosen as you use it so you’ll need to check it regularly and tighten it. However, if you tighten the chain too much, it will not spin freely around the bar and increased friction will result in smoke.

Adjust the chain tension on a SENIX chainsaw:

  • Remove the spark plug wire.
  • Unlock the chain brake.
  • Loosen the bar retaining nuts that hold the cover over the clutch. Don’t remove the cover.
  • Turn the tensioning screw counter-clockwise to loosen the chain and clockwise to tighten the chain.
  • The chain should be about 1/8 inch or 3mm of space between the chain and the bar when pulling the chain away from the bar.
  • Once you achieve the correct tension, tighten the bar retaining nuts.

You want the chain to sit securely around the bar, but still able to move easily. You don’t want it too loose that it hangs from the guide bar.

SENIX Chainsaw Smoking from the Exhaust

When your chainsaw smokes while running, you will need to look at airflow issues including a plugged air filter or a problem with the fuel mixture.

Clogged Air Filter

Operating a chainsaw is a dirty job. Sawdust and small wood chips are tossed into the air.

An air filter is used on your chainsaw to ensure the engine receives clean air. The filter keeps dirt and sawdust from entering the carburetor throat and wearing on the engine.

If you use your chainsaw sparingly, replace your air filter annually and check it before each use. If you use the saw regularly, check the filter frequently and replace it when it becomes very dirty or damaged.

If you don’t regularly check and clean the filter to ensure it is in good condition, it can become so clogged that air isn’t able to pass through it.

The fuel will run rich and smoke. The engine may eventually shut down due to a lack of air.

Low Engine Oil Level or Too Much Engine Oil

Low engine oil level: Air-cooled engine oil is used to keep the engine cool and provide sufficient lubrication.

When there isn’t enough engine oil, the engine will build heat that can become so intense that it melts engine parts and oil begins to burn and smoke.

Too much engine oil: Placing too much engine oil in the crankcase won’t allow engine parts to move freely. Increased pressure will build in the crankcase and parts will be put under an increased load creating heat.

The increased pressure may push excess oil into the cylinder causing oil to burn and leave behind a bluish-white smoke.

Water in the Fuel System

Water in the fuel can cause white exhaust smoke. Water is corrosive to the fuel system and engine.

Instead of trying to figure out a way to save fuel and remove water, it’s best to empty the fuel tank and refill it with fresh gasoline.

Add in a fuel additive like Sea Foam Motor Treatment to help remove moisture and clean the fuel system. Start the saw and allow it to run to get the treated fuel through the system.