When it comes to reliable and powerful chainsaws, the Stihl MS 390 is a popular choice among professionals and homeowners. However, like any mechanical device, it is not immune to occasional problems that can hinder its performance. In this article, we will explore common Stihl MS 390 problems and provide practical solutions to address them. Come on and read right now!

Stihl MS 390 Problems

Stihl MS 390 won’t start

Cause: 

• Fuel-related issues, such as old or contaminated fuel, clogged fuel filter, or improper fuel mixture.
• Ignition system problems, such as a faulty spark plug or ignition switch.

Solution:

1. Ensure you are using fresh, high-quality fuel mixed with the correct ratio of gasoline and oil.
2. Check the fuel filter for debris or clogs and clean or replace it if necessary.
3. Inspect the spark plug for signs of wear or damage and replace if needed.
4. Verify that the ignition switch is in the “On” position and functioning correctly.

The Chain Not Lubricating Properly

Cause:

• Clogged or malfunctioning oil delivery system.
• Incorrect chain oil viscosity or inadequate oil levels.

Solution:

1. Clean the oil delivery holes, bar groove, and oil pump if they are clogged or obstructed.
2. Check the chain oil reservoir and fill it with the recommended oil type up to the indicated level.
3. Ensure that the oil viscosity matches the manufacturer’s specifications for optimal lubrication.

Loss of Power or Stalling

Cause: 

• Clogged air filter restricting airflow.
• A fouled spark plug.
• Carburetor issues, such as clogging, improper adjustment, or fuel blockage.

Solution: 

1. Clean or replace the air filter regularly to ensure proper airflow.
2. Check the spark plug for signs of fouling or wear and clean or replace it accordingly.
3. Inspect the carburetor for any clogs or debris, adjusting it to the manufacturer’s specifications. If necessary, clean or rebuild the carburetor to resolve fuel blockage issues.

Chain Brake Not Working

Cause: 

• Worn or damaged brake band.
• Malfunctioning brake handle or mechanism.

Solution:

1. Examine the brake band for signs of wear or damage. Replace the brake band if necessary.
2. Inspect the brake handle and mechanism, ensuring they are properly lubricated and functioning smoothly. If there are any damaged components,
3. replace them as needed.

Excessive vibration

Cause:

• Loose or worn chain.
• Damaged or unbalanced guide bar.
• Loose fasteners or parts within the chainsaw.

Solution: 

1. Ensure the chain tension is correct according to the manufacturer’s guidelines.
2. Inspect the guide bar for damage or excessive wear. Replace the guide bar if necessary.
3. Tighten all fasteners and components, including the chain, guide bar, and housing, to minimize vibration.

Overheating of Stihl MS 390

Cause: 

• Running the chainsaw continuously without proper cooling breaks.
• Clogged or dirty air vents and cooling fins.
• Excessive workload or improper fuel mixture leading to engine overheating.

Solution:

1. Avoid running the chainsaw for extended periods without giving it time to cool down.
2. Regularly clean the air vents and cooling fins to ensure optimal airflow.
3. Use the correct fuel mixture and avoid overloading the chainsaw beyond its recommended capabilities.

Stihl MS 390 leaking oil

Cause: 

• Damaged or worn oil seals.
• Loose or improperly fitted oil cap.
• Clogged oil tank vent.

Solution:

1. Inspect the oil seals for any signs of damage or wear. Replace them if necessary.
2. Ensure that the oil cap is securely tightened and properly seated to prevent leaks.
3. Check the oil tank vent for blockages and clean it thoroughly to maintain proper pressure balance.

FAQs

Can I use regular gasoline in my Stihl MS 390?

No, it is not recommended to use regular gasoline in the Stihl MS 390 chainsaw. The manufacturer recommends using a high-quality gasoline with an octane rating of 89 or higher.

Additionally, it is crucial to mix the gasoline with a high-quality two-stroke engine oil at the correct ratio as specified by Stihl (typically 50:1). Using regular gasoline or an incorrect fuel mixture can lead to poor performance, increased wear on the engine, and potential damage to the chainsaw.

How can I prevent chain tensioning problems on my Stihl MS 390?

To prevent chain tensioning problems on your Stihl MS 390, follow these steps:

1. Regularly inspect the chain tension and adjust it as necessary. Proper chain tension is crucial for safe and efficient cutting.
2. Ensure that the chain brake is disengaged before adjusting the chain tension.
3. Use the provided tool or a wrench to adjust the tensioning screw located on the side of the chainsaw.
4. Avoid overtightening the chain, as it can lead to accelerated wear and decreased cutting performance.
5. Check the owner’s manual for specific guidelines on chain tensioning and follow them accordingly.
6. Keep the guide bar clean and free from debris, as buildup can affect proper chain tension.

Can the Stihl MS 390 chainsaw be used for professional applications?

Yes, the Stihl MS 390 chainsaw can be used for professional applications. With its powerful engine, high-quality construction, and durability, the Stihl MS 390 is well-suited for demanding cutting tasks encountered by professionals in forestry, tree care, landscaping, and other related industries. It offers the necessary power, performance, and reliability required for prolonged and heavy-duty use.

Does the Stihl MS 390 chainsaw have a decompression valve?

No, the Stihl MS 390 chainsaw does not come equipped with a decompression valve. The decompression valve is a feature found on some chainsaws that helps reduce compression during the starting process, making it easier to pull the starter cord. While the Stihl MS 390 lacks this particular feature, it still provides reliable starting capabilities with its high-quality components and design.

Is the Stihl MS 390 chainsaw compatible with different types of chains?

Yes, the Stihl MS 390 chainsaw is compatible with various types of chains. It can accommodate chains with different pitches, such as 0.325″ or 3/8″. This compatibility allows users to choose the most suitable chain depending on their specific cutting needs, whether it be for general cutting, firewood, or more specialized tasks.

Stihl provides a range of STIHL Oilomatic saw chains, such as Rapid Super (RS) and Rapid Micro (RM), which are compatible with the Stihl MS 390 chainsaw, ensuring optimal cutting performance and durability.

Conclusion

By being aware of the potential problems that can arise with the Stihl MS 390 chainsaw and learning how to resolve them, users can overcome obstacles that may hinder their cutting tasks. Remember, regular maintenance, following manufacturer guidelines, and using high-quality fuel and lubricants are key to preventing many of these issues.