How to Change Spark Plug Stihl Ms170: Your Ultimate DIY Guide

Are you experiencing trouble starting your Stihl MS170 chainsaw? A faulty spark plug could be the culprit. This guide will walk you through the process of how to change spark plug stihl ms170, ensuring your chainsaw runs smoothly and efficiently.

Why Change the Spark Plug?

The spark plug plays a crucial role in igniting the fuel-air mixture in your chainsaw’s engine. Over time, it can become worn or fouled, leading to:

• Difficult starting: A worn spark plug may not generate a strong enough spark to ignite the fuel, making it difficult to start the chainsaw.
• Rough running: A fouled spark plug can cause the engine to misfire, resulting in rough idling and inconsistent power.
• Reduced performance: A spark plug that’s not functioning properly can limit the engine’s power output, making it harder to cut through wood.
• Increased fuel consumption: A faulty spark plug can lead to inefficient combustion, resulting in higher fuel consumption.

Tools and Materials

Before you begin, gather the following tools and materials:

• New spark plug: Ensure you purchase the correct spark plug for your Stihl MS170. Refer to your owner’s manual or contact your local Stihl dealer for the correct part number.
• Spark plug wrench: This tool is specifically designed to remove and install spark plugs.
• Socket wrench: A 10mm socket wrench will be needed to remove the spark plug cover.
• Gloves: Protect your hands from dirt and potential cuts.
• Safety glasses: Protect your eyes from flying debris.

Safety Precautions

• Always disconnect the spark plug wire before working on the chainsaw. This prevents accidental starting and potential injury.
• Wear appropriate safety gear, including gloves and safety glasses, to protect yourself from potential hazards.
• Work in a well-ventilated area to avoid inhaling harmful fumes.
• Never attempt to start the chainsaw while the spark plug is removed.

Step-by-Step Guide to Change Spark Plug Stihl MS170

Now, let’s get started with changing the spark plug:

1. Disconnect the spark plug wire: Locate the spark plug wire, which is connected to the spark plug. Pull the wire off the spark plug to disconnect the electrical circuit.
2. Remove the spark plug cover: Using a 10mm socket wrench, loosen and remove the spark plug cover. This cover protects the spark plug from dirt and debris.
3. Remove the old spark plug: Using the spark plug wrench, grasp the old spark plug and turn it counterclockwise to loosen it. Once it’s loose, you can remove it completely.
4. Inspect the old spark plug: Before installing the new spark plug, take a moment to inspect the old one. Look for signs of wear, fouling, or damage. This can help you determine if there are any other issues with the chainsaw.
5. Install the new spark plug: Screw the new spark plug into the spark plug hole by hand until it is snug. Then, use the spark plug wrench to tighten it to the proper torque specification. This information is usually found in the chainsaw’s owner’s manual.
6. Reconnect the spark plug wire: Carefully connect the spark plug wire back to the new spark plug. Ensure it is securely connected.
7. Reinstall the spark plug cover: Place the spark plug cover back on and tighten it using the 10mm socket wrench.
8. Test the chainsaw: Once the new spark plug is installed, you can start the chainsaw and test it. The engine should start easily and run smoothly.

Troubleshooting Tips

If you’re still having trouble with your Stihl MS170 after changing the spark plug, consider these troubleshooting tips:

• Check the fuel and air filters: Clogged filters can restrict fuel and air flow, affecting engine performance.
• Inspect the carburetor: A dirty or malfunctioning carburetor can cause starting and running problems.
• Check the ignition system: If the ignition coil or other components are faulty, the spark plug won’t be able to ignite the fuel.

Keeping Your Chainsaw in Top Condition

Changing the spark plug is just one aspect of maintaining your Stihl MS170 chainsaw. Here are some additional tips to keep your chainsaw running smoothly:

• Regularly clean and maintain the air filter: A clean air filter ensures proper airflow to the engine.
• Change the fuel filter as needed: A clogged fuel filter can restrict fuel flow, causing starting and running problems.
• Keep the chainsaw lubricated: Regularly lubricate the chain and bar to prevent wear and tear.
• Store the chainsaw properly: Store the chainsaw in a dry, clean place when not in use.

A Smooth-Running Chainsaw: The Final Word

By following these steps, you can confidently change the spark plug on your Stihl MS170 chainsaw. A new spark plug will ensure your chainsaw starts easily, runs smoothly, and delivers optimal performance. Remember to always prioritize safety and use proper tools and techniques.

Common Questions and Answers

Q: How often should I change the spark plug on my Stihl MS170?

A: It’s generally recommended to change the spark plug every 100 hours of operation or annually, whichever comes first. However, you should always refer to your chainsaw’s owner’s manual for the specific maintenance schedule.

Q: What should I do if my new spark plug doesn‘t solve the starting problem?

A: If the problem persists, you may need to investigate other potential issues, such as a clogged air filter, a dirty carburetor, or a faulty ignition system. Consult your chainsaw’s owner’s manual for troubleshooting guidance or contact a qualified technician for assistance.

Q: Can I use a different type of spark plug on my Stihl MS170?

A: It’s crucial to use the specific type of spark plug recommended by the manufacturer. Using an incorrect spark plug can damage the engine or result in poor performance. Refer to your owner’s manual or contact a Stihl dealer for the correct part number.

Q: What are the signs of a fouled spark plug?

A: A fouled spark plug will often have a black, oily, or carbon-coated electrode. This indicates that the spark plug is not firing properly due to excess fuel or oil buildup.