6 Most Common STIHL MS 291 Problems and Solutions

STIHL MS 291 is a powerful, versatile chainsaw that gardeners, farmers, and landscapers can use with minimal fuss. Its gas-powered engine offers a longer run time, allowing you to handle multiple tasks around your home. 

You can use your chainsaw for felling wood, pruning branches, and clean-up tasks after storms. However, you may experience several problems when operating this chainsaw. The most common STIHL MS 291 problems are problematic starts, overheating, speed adjustment issues, power loss, and air/fuel filter issues. 

This article discusses these problems and offers practical solutions to ensure your STIHL MS 291 chainsaw runs smoothly.

STIHL MS 291 Starting Problems

Like most gas-fueled engines, the STIHL MS 291 develops starting problems with time. Users complain that it takes multiple attempts before the engine starts. Sometimes, the engine may fail to start at all.

If your chainsaw is okay, it may struggle to start in extreme weather conditions. In this case, the engine may become rigid to start.

However, if the weather does not cause starting problems in your chainsaw, inspect internal components to identify the cause. The main culprits could be bad gas, a damaged or dirty spark plug, and a clogged carburetor.

Leaving gas in the fuel system for more than three months does more harm to the engine. You may notice that the chainsaw engine stalls and fails to start.

We all know that insufficient gas in the fuel tank can cause starting problems. This is because less gas in the tank won’t reach the cylinder. Similarly, excess gas in the fuel tank can cause starting problems.

Effective Solutions:

  • First, consider how long you’ve stored your chainsaw with the gas. If it’s over two months, drain the old gas from the tank and the fuel system. You can shake the saw to drain the gas in the fuel system. Then, add fresh gas and start the engine.
  • A low level of gas in the tank can cause starting issues. Inspect the fuel tank and add more gas if necessary.
  • If you’ve overfilled the fuel tank, use a siphon pump to remove excess gas.
  • Inspect the spark plug to see if it’s dirty or damaged. If it’s dirty, remove it and wipe the dirt out with a clean cloth. Replace the plug if it appears burnt.
  • Check if the problem emanates from a clogged carburetor. Use a carburetor cleaner to remove any dirt and debris. You can replace the carburetor if it’s faulty.


Overheating is a common problem among STIHL MS 291 chainsaws. This problem may result from insufficient oil, blunt chain, incorrect chain tension, and blocked exhaust port.

If your STIHL MS 291 fuel mixture lacks oil, the engine will overheat and affect the overall performance.

The chain could also be the culprit. If you’re using a blunt chain, the chainsaw will require more power to cut trees. Additionally, if the chain has too much tension, it’ll strain the engine and cause it to overheat.

Effective Solutions:

  • Consult the owner’s manual to determine your chainsaw’s correct oil-to-gas ratio. Add fresh oil or gas to achieve the proper balance.
  • Inspect the chain to see if it’s blunt. If the teeth along the chain are dull, use a chain sharpener to sharpen them. You can also replace the chain if it appears damaged.
  • Ensure there’s correct tension on the chain.
  • Check the exhaust port for dirt, debris, and carbon. Remove the clog and run your engine.

Speed Adjustment Problem

The speed adjustment issue is one of the most common STIHL MS 291 problems. The chainsaw features screws that allow you to adjust to low or high speed. This ensures the machine is convenient for different applications.

Unfortunately, the screws may fail to respond when switching to your desired speed. This problem usually results from an incorrect setting of the screws. Failure to adjust the screws affects the engine’s speed and rpm.

Effective Solution:

Before solving this problem, start the engine and allow it to warm up for a few minutes. You can fix this problem by adjusting the settings. When doing this, you must ensure the chain is running. You must also ensure the air filter is clean and appropriately fitted in its place.

Power Loss

Your STIHL MS 291 may lose power while operating it. Two main reasons account for this problem: insufficient compression and a clogged spark arrestor.

When the spark arrestor is clogged, the engine will start, but the motor will die after pulling the trigger.

If the engine power problems result from insufficient compression, your chainsaw probably suffers from a damaged cylinder or piston. Another component to check is the spark plug for proper tightening.

Effective Solutions:

  • Inspect the cylinder and piston to see if they’re damaged. If there are scars on the cylinder, replace it. You’ll also need to replace the piston if it’s damaged.
  • Inspect the spark plug at the top of the cylinder head to see if it’s securely tightened. If not, fit it to ensure it’s tight.
  • Check the spark arrestor for clogging on the wire screen. If it appears clogged, use a carburetor cleaner to spray on the buildup. The cleaner should remove the buildup in a few minutes. Then, remove the residual with a wire brush.

Air Filter Problems

The air filter is the next component to check when encountering STIHL MS 291 problems. If you’ve used your chainsaw for an extended period, you’re probably struggling with a clogged air filter.

A clogged air filter causes the engine to overheat or fail to start. Sometimes, these problems occur if the air filter is faulty.

Remove the air filter from your chainsaw and start the engine to determine if it is the culprit. If the engine runs well without the air filter, you’ve already identified the cause.

Effective Solutions:

  • Inspect the air filter to see if it accumulates dirt and debris. Use a vacuum to remove the dirt. Alternatively, use a toothbrush and a cleaning liquid to remove the dirt particles.
  • If the air filter is damaged, replace it.

Fuel Filter Issues

Fuel filter problems can cause your chainsaw to shut down or fail to start. Often, fuel filter problems occur if the fuel filter is clogged.

Dirt, debris, and contaminants can accumulate in the fuel and clog the filter. When this happens, the filter prevents the engine from receiving sufficient fuel. As a result, your chainsaw may keep shutting down or fail to start.

Effective Solutions:

  • Remove the fuel filter and inspect it to see if it’s clogged. If you notice dirt and debris on the fuel filter, replace it.
  • Check if the fuel filter is broken. A broken fuel filter will cause fuel to leak, creating strong odors. If you have a broken fuel filter, replace it.

Closing Thoughts

The best way to keep your STIHL MS 291 in top condition is by maintaining it regularly. Proper maintenance will allow your chainsaw to last longer and handle multiple tasks.

However, that’s not to say your chainsaw will be immune to the common STIHL MS 291 problems. If you encounter any of the above problems, use our solutions to fix them. If fixing the problem is beyond your capabilities, take it to a professional for troubleshooting.