Troubleshooting a Stihl Chainsaw That Won't Start: Common Issues and Solutions

Troubleshooting a Stihl Chainsaw That Won’t Start: Common Issues and Solutions

A Stihl chainsaw is a powerful tool that can make light work of cutting trees and firewood, but it’s only as useful as its ability to start and run smoothly. If you find yourself in a situation where your Stihl chainsaw won’t start, you’re not alone. Many chainsaw owners encounter this issue at some point, and there can be a variety of reasons behind it. In this guide, we will dive into the common problems that can prevent your Stihl chainsaw from starting and provide you with practical solutions to get it back up and running.

Checking the Basics

Before delving into specific scenarios, it’s essential to check the basics. Often, a Stihl chainsaw won’t start due to simple issues that can be easily resolved.

1. Fuel and Oil: Ensure that your chainsaw has the correct fuel-oil mixture if it’s a gas-powered model. Refer to the manufacturer’s instructions for the right ratio. Also, ensure that there’s sufficient bar and chain oil in the reservoir.

2. Air Filter: A clogged or dirty air filter can restrict airflow to the engine, causing starting problems. Remove the air filter cover and inspect the filter. Clean or replace it if necessary.

3. Spark Plug: Examine the spark plug for signs of wear, fouling, or damage. A damaged spark plug can prevent ignition. Replace it if needed.

4. Pull Cord: Check the pull cord for any damage or fraying. If it’s worn out, it may not engage properly, making it difficult to start the chainsaw.

5. Safety Precautions: Always follow safety guidelines and wear appropriate protective gear when working with a chainsaw. Ensure the chain brake is engaged and the throttle lock is on before attempting to start the chainsaw.

Stihl Chainsaw Won’t Start After Refueling

If your Stihl chainsaw won’t start immediately after refueling, it can be frustrating, but there are a few common issues and solutions to consider.

1. Common Causes:

  • Incorrect Fuel Mixing: Using the wrong fuel-oil mixture can prevent the engine from starting.
  • Fuel Tank Venting: If the fuel tank doesn’t vent properly, it can create a vacuum that hinders fuel flow.

2. Solution: Proper Fuel Mixing: Double-check that you’ve mixed the correct fuel-oil ratio. Stihl recommends a specific ratio for each chainsaw model, typically around 50:1. Using a pre-mixed fuel can also eliminate this issue.

3. Solution: Venting the Fuel Cap: Sometimes, the fuel cap can become clogged or fail to vent properly, causing a vacuum in the tank. Try loosening the fuel cap slightly to allow air in and see if the chainsaw starts. If it does, consider replacing the fuel cap if necessary.

Stihl Chainsaw Won’t Start After Running

If your Stihl chainsaw runs fine but refuses to start again after being shut down, there could be a few underlying issues.

1. Common Causes:

  • Overheating: Chainsaws can overheat during prolonged use, and the engine may need time to cool down before it can restart.
  • Clogged Air Filter: A dirty air filter restricts airflow, which can lead to overheating.
  • Fouled Spark Plug: Overheating can also cause the spark plug to foul.

2. Solution: Cooling Down: Allow the chainsaw to cool down for a few minutes before attempting to restart it. Avoid prolonged periods of continuous use to prevent overheating.

3. Solution: Clean the Air Filter: Check and clean the air filter if it’s dirty or clogged. A clean filter ensures proper airflow to the engine.

4. Solution: Check for Fouled Spark Plug: If the spark plug is fouled, remove and clean it, or replace it with a new one. A clean spark plug is essential for ignition.

Stihl Chainsaw Won’t Start After Sitting

When your Stihl chainsaw has been sitting idle for an extended period, it may not start immediately. This can be due to issues related to fuel deterioration and carburetor clogs.

1. Common Causes:

  • Stale Fuel: Gasoline can become stale and ineffective after a few months, making it difficult to start the chainsaw.
  • Carburetor Clogs: Over time, the carburetor may become clogged with varnish and debris.

2. Solution: Fuel Stabilization: To prevent fuel from going stale, use a fuel stabilizer when storing your chainsaw for an extended period. This will help maintain the quality of the fuel in the tank.

3. Solution: Carburetor Cleaning: If the carburetor is clogged, it may need cleaning. Consider taking your chainsaw to a professional for this task if you’re not comfortable doing it yourself.

Specific Models:

Let’s address common starting issues for two specific Stihl chainsaw models: the Stihl MS 170 and the Stihl MS 250.

1. Stihl MS 170 Will Not Start

  • The Stihl MS 170 is a popular homeowner’s chainsaw, but it can also face starting issues.
  • Follow the general troubleshooting steps mentioned earlier, focusing on fuel mix, air filter, spark plug, and fuel system maintenance.
  • Ensure that you’re using the correct starting procedure for your specific model, as outlined in the owner’s manual.

2. Stihl MS 250 Will Not Start

  • The Stihl MS 250 is a higher-powered chainsaw often used for more demanding tasks.
  • If your MS 250 won’t start, check the same components as mentioned earlier and ensure you’re using the appropriate fuel-oil mixture.
  • Pay special attention to the condition of the spark plug, as the MS 250 may have a higher combustion pressure that demands a well-functioning plug.

Preventive Maintenance

To keep your Stihl chainsaw in good working order and reduce the likelihood of starting issues, consider these preventive maintenance tips:

1. Regular Cleaning

  • Clean your chainsaw regularly, removing sawdust, dirt, and debris from the air filter, engine, and chain area.
  • Keep the chain sharp and properly tensioned.

2. Fuel Management

  • Use fresh fuel and follow the manufacturer’s recommendations for fuel-oil mixing ratios.
  • Use a fuel stabilizer when storing your chainsaw for extended periods.

3. Professional Servicing

  • Periodically take your chainsaw to a professional for a thorough inspection and maintenance, especially if you encounter persistent starting problems.


A Stihl chainsaw that won’t start can be frustrating, but with the right troubleshooting steps and maintenance practices, you can often diagnose and resolve the issue. Remember to start with the basics, such as fuel and air filter checks, and then proceed to more specific solutions depending on the situation. Regular preventive maintenance will go a long way in keeping your Stihl chainsaw in excellent working condition, ensuring that it starts reliably when you need it most.

Raphael Dume
Raphael Dume

Raphael Dume, bestselling author and internet entrepreneur, is the visionary behind He developed this platform to inspire and educate outdoor enthusiasts., driven by a team of experts, offers accurate, insightful content and resources for adventurers of all levels. The site is a trusted guide for outdoor tips, gear reviews, and experiences, reflecting Raphael's passion for the outdoors and commitment to fostering a community of nature lovers.

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