Stihl MS170 Chain Replacement Tips (Optimize Cutting & Sharpening)

Imagine transforming your Stihl MS170 chainsaw from a frustrating, underperforming tool into a wood-devouring beast, effortlessly slicing through logs and making firewood preparation a breeze. That’s precisely what I’m going to help you achieve in this guide. We’ll cover everything from choosing the right chain to mastering sharpening techniques, ensuring your MS170 operates at its peak potential.

Stihl MS170 Chain Replacement Tips: Optimizing Cutting & Sharpening

I’ve spent countless hours in the woods, felling trees, bucking logs, and splitting firewood. My experience ranges from helping my grandfather with his small firewood business as a kid to now managing woodland on my own property. I’ve learned firsthand the importance of a well-maintained chainsaw, and the Stihl MS170, while a smaller model, is a reliable workhorse when properly cared for. A dull chain on any chainsaw, but especially a smaller saw like the MS170, can turn a simple task into a grueling chore. It’s not just about speed; it’s about safety, efficiency, and the longevity of your saw.

Understanding the User Intent

The user searching for “Stihl MS170 Chain Replacement Tips (Optimize Cutting & Sharpening)” is likely experiencing one or more of these issues:

• Dull Chain: The saw isn’t cutting as efficiently as it used to. It requires more pressure and produces fine sawdust instead of larger chips.
• Chain Damage: The chain has been damaged by hitting rocks, metal, or other foreign objects.
• Slow Cutting: The cutting speed has decreased, making firewood preparation a time-consuming process.
• Difficulty Starting Cuts: The saw struggles to initiate a cut, often bouncing or chattering.
• Uneven Cutting: The saw cuts at an angle or pulls to one side.
• General Maintenance: The user wants to perform routine maintenance to keep their saw in optimal condition.
• Chain Replacement: The user needs to replace the chain and wants to ensure they select the correct type and install it properly.
• Sharpening Technique: The user wants to improve their chain sharpening skills for better cutting performance.

Key Concepts: Chainsaw Chains and Their Importance

Before diving into the specifics of chain replacement and sharpening, let’s define some key terms and concepts:

• Chain Pitch: The distance between any three consecutive rivets on the chain, divided by two. This is usually measured in inches (e.g., 3/8″ low profile, .325″). The MS170 typically uses a 3/8″ low profile chain.
• Chain Gauge: The thickness of the drive links (the part of the chain that sits in the guide bar groove). This is usually measured in thousandths of an inch (e.g., .050″, .043″). The MS170 typically uses a .050″ gauge chain.
• Drive Links: The number of these determines the overall length of the chain and whether it fits your specific guide bar.
• Cutter Type: There are different types of cutters, such as chisel, semi-chisel, and low-profile. The MS170 usually uses low-profile cutters designed for smaller saws and safety.
• Green Wood vs. Seasoned Wood: Green wood is freshly cut and contains a high moisture content, making it heavier and harder to split. Seasoned wood has been allowed to dry, reducing its moisture content and making it easier to burn.
• Kickback: A dangerous phenomenon where the chain catches on the wood and throws the saw back towards the operator. Proper chain maintenance and technique can significantly reduce the risk of kickback.

Understanding these concepts is fundamental to selecting the right chain and maintaining it properly.

Step-by-Step Guide: Stihl MS170 Chain Replacement

Replacing the chain on your Stihl MS170 is a straightforward process, but it’s crucial to follow each step carefully to ensure safety and proper operation.

Step 1: Safety First

• Engage the Chain Brake: Always engage the chain brake before performing any maintenance on your chainsaw. This prevents accidental chain movement.
• Remove the Spark Plug Wire: Disconnect the spark plug wire to prevent the saw from starting accidentally. Tuck the wire away from the spark plug.
• Wear Gloves: Wear work gloves to protect your hands from sharp chain cutters and dirt.

Step 2: Loosening the Bar Nuts

• Locate the Bar Nuts: The bar nuts are located on the side of the chainsaw, usually covered by a chain brake lever.
• Use the Combination Wrench: The Stihl MS170 usually comes with a combination wrench. Use the appropriate end to loosen the bar nuts. Don’t remove them completely yet.
• Slightly Loosen: Loosen the nuts just enough to allow the bar cover to move.

Step 3: Removing the Bar Cover and Old Chain

• Remove the Bar Cover: Once the bar nuts are loose, carefully remove the bar cover.
• Inspect the Sprocket: Before removing the chain, take a quick look at the sprocket. A worn sprocket can damage new chains, so replace it if necessary. Sprocket replacement is usually needed after every 2-3 chain replacements.
• Remove the Old Chain: Carefully remove the old chain from the guide bar. Be mindful of the sharp cutters.

Step 4: Inspecting the Guide Bar

• Clean the Guide Bar: Use a wire brush or a flat file to clean the guide bar groove. Remove any debris, sawdust, or oil buildup.
• Check for Damage: Inspect the guide bar for wear, burrs, or damage. Run your finger along the edges of the groove. If you feel any sharp edges or unevenness, the guide bar needs to be dressed or replaced.
• Dressing the Guide Bar: Use a guide bar dressing tool (a specialized flat file) to remove burrs and smooth out the edges of the groove. This ensures the chain sits properly and reduces friction.

Step 5: Selecting the Correct Replacement Chain

• Check Your Owner’s Manual: Your Stihl MS170 owner’s manual will specify the correct chain type, pitch, gauge, and number of drive links.
• Measure the Old Chain (If Possible): If you still have the old chain, you can use it to determine the correct specifications for the new chain. Count the number of drive links and measure the pitch and gauge.
• Common Chain Specifications for MS170: The Stihl MS170 typically uses a 3/8″ low profile chain with a .050″ gauge and the number of drive links will depend on the bar length (usually 50 or 55 drive links for a 16″ bar).
• Choosing the Right Cutter Type: For the MS170, I recommend sticking with a low-profile chain. These chains are designed for safety and are less prone to kickback, especially important for less experienced users.
• Example: I once made the mistake of using a .325 pitch chain on my MS170 after grabbing the wrong box at the hardware store. The saw vibrated excessively and cut poorly. It was a valuable lesson in paying attention to the chain specifications!

Step 6: Installing the New Chain

• Position the Chain on the Guide Bar: Place the new chain around the guide bar, ensuring the cutters are facing the correct direction. The cutters should point forward in the direction of chain rotation. If you install it backward, the saw will not cut.
• Align the Guide Bar with the Saw: Place the guide bar back onto the saw, aligning the mounting studs with the holes in the guide bar.
• Engage the Chain with the Sprocket: Make sure the drive links of the chain are properly engaged with the sprocket.
• Adjust Chain Tension: Before tightening the bar nuts, adjust the chain tension. There’s usually a tensioning screw on the side of the saw near the bar. Use a screwdriver to adjust the tension until the chain sits snugly in the guide bar groove but can still be pulled around by hand. A properly tensioned chain should have about 1/8″ of sag on the underside of the guide bar.

Step 7: Tightening the Bar Nuts

• Tighten the Bar Nuts Securely: Once the chain tension is properly adjusted, tighten the bar nuts securely with the combination wrench.
• Recheck Chain Tension: After tightening the nuts, recheck the chain tension. It may be necessary to readjust slightly.

Step 8: Final Inspection

• Rotate the Chain by Hand: Rotate the chain by hand to ensure it moves freely and is properly engaged with the sprocket.
• Check Cutter Direction: Double-check that the cutters are facing the correct direction.
• Reinstall Spark Plug Wire: Reconnect the spark plug wire.

Step 9: Test the Chain

• Start the Saw: Start the saw and make a few test cuts on a small piece of wood.
• Observe Cutting Performance: Observe the cutting performance. The saw should cut smoothly and efficiently. If the saw vibrates excessively or cuts poorly, recheck the chain tension and installation.

Optimizing Cutting Performance: Chain Sharpening

A sharp chain is crucial for efficient and safe cutting. A dull chain requires more pressure, which can strain the saw and increase the risk of kickback.

Understanding Chain Sharpening Angles

• Top Plate Angle: The angle of the top plate relative to the side plate.
• Side Plate Angle: The angle of the side plate relative to the depth gauge.
• Depth Gauge Setting: The height difference between the cutter and the depth gauge. The depth gauge controls how much wood the cutter takes with each pass.

The correct angles and depth gauge setting will vary depending on the type of chain and the manufacturer’s recommendations. Your owner’s manual will have this information.

Methods for Sharpening Chainsaw Chains

There are several methods for sharpening chainsaw chains:

• Hand Filing: Using a round file and a file guide to sharpen each cutter individually.
• Electric Chain Sharpener: Using an electric sharpener with grinding wheels to sharpen the cutters.
• Dremel Tool: Using a Dremel tool with a grinding attachment to sharpen the cutters.

I personally prefer hand filing for maintaining my chains in the field. It’s portable, doesn’t require electricity, and allows me to precisely sharpen each cutter. However, for heavily damaged chains or for sharpening multiple chains at once, an electric sharpener can be more efficient.

Hand Filing: A Step-by-Step Guide

• Secure the Chainsaw: Clamp the chainsaw in a vise or secure it to a workbench.
• Engage the Chain Brake: Engage the chain brake to prevent the chain from moving.
• Select the Correct File Size: Use the correct size round file for your chain’s pitch. The file size will be specified in your owner’s manual or on the chain packaging. For a 3/8″ low profile chain, a 5/32″ file is usually appropriate.
• Use a File Guide: A file guide helps maintain the correct sharpening angles. Place the file guide on the chain, aligning it with the cutter.
• File the Cutters: File each cutter using smooth, consistent strokes. Follow the angle markings on the file guide. File from the inside of the cutter to the outside.
• Maintain Consistent Strokes: Use the same number of strokes for each cutter to ensure they are all sharpened to the same length.
• Check for Burrs: After filing, check for burrs on the cutters. Remove any burrs with a flat file.
• Lower the Depth Gauges: Use a flat file and a depth gauge tool to lower the depth gauges. The depth gauge setting will vary depending on the chain type and the manufacturer’s recommendations.
• Sharpen All Cutters: Sharpen all the cutters on the chain, alternating between the left and right cutters.
• Test the Chain: After sharpening, test the chain by making a few cuts on a piece of wood. The saw should cut smoothly and efficiently.

Electric Chain Sharpener: A Step-by-Step Guide

• Mount the Sharpener: Mount the electric chain sharpener on a workbench or other stable surface.
• Adjust the Grinding Wheel: Adjust the grinding wheel to the correct angle for your chain.
• Secure the Chain: Place the chain in the sharpener and secure it in place.
• Sharpen the Cutters: Sharpen each cutter by briefly touching it to the grinding wheel. Use light pressure and avoid overheating the cutter.
• Maintain Consistent Sharpening: Sharpen each cutter to the same length and angle.
• Lower the Depth Gauges: Use a depth gauge tool and a flat file to lower the depth gauges.
• Test the Chain: After sharpening, test the chain by making a few cuts on a piece of wood.

Maintaining Your Chainsaw Chain

• Regular Sharpening: Sharpen your chain regularly to maintain optimal cutting performance. I usually sharpen my chain after every 2-3 tanks of fuel, or whenever I notice a decrease in cutting performance.
• Proper Chain Tension: Maintain proper chain tension to prevent the chain from derailing and to reduce wear on the guide bar and sprocket.
• Lubrication: Use a high-quality bar and chain oil to lubricate the chain. Proper lubrication reduces friction and extends the life of the chain, bar, and sprocket.
• Cleaning: Clean the chain and guide bar regularly to remove sawdust and debris.
• Storage: Store your chainsaw in a clean, dry place. Remove the chain and guide bar for long-term storage.

Case Study: Reviving a Neglected MS170

I once acquired a used Stihl MS170 from a neighbor who was moving. The saw was in rough shape. The chain was incredibly dull, the guide bar was worn, and the saw ran poorly.

Here’s what I did to revive it:

1. Replaced the Chain: I replaced the old, dull chain with a new Stihl 3/8″ low profile chain.
2. Dressed the Guide Bar: I used a guide bar dressing tool to remove burrs and smooth out the edges of the guide bar.
3. Cleaned the Saw: I thoroughly cleaned the saw, removing sawdust and debris from the engine, air filter, and cooling fins.
4. Replaced the Air Filter: I replaced the dirty air filter with a new one.
5. Cleaned the Carburetor: I cleaned the carburetor to ensure proper fuel flow.
6. Adjusted the Carburetor: I adjusted the carburetor settings to optimize engine performance.

After these repairs, the MS170 ran like a new saw. It cut smoothly and efficiently, and it was a pleasure to use. This experience reinforced the importance of regular maintenance and proper chain care.

1. Assess Your Current Chain: Evaluate the condition of your current chain. Is it dull, damaged, or simply worn out?
2. Gather Your Tools: Assemble the necessary tools for chain replacement and sharpening, including a combination wrench, round file, file guide, depth gauge tool, and bar and chain oil.
3. Replace or Sharpen Your Chain: Follow the step-by-step guides outlined in this article to replace or sharpen your chain.
4. Practice Safe Cutting Techniques: Always prioritize safety when operating a chainsaw. Wear appropriate safety gear and follow proper cutting techniques.
5. Maintain Your Chainsaw Regularly: Perform regular maintenance on your chainsaw to keep it in optimal condition. This includes cleaning, lubricating, and inspecting the chain, guide bar, and sprocket.
6. Start a Firewood Project: Put your newfound knowledge to use by starting a firewood project. Fell a tree, buck it into logs, split the logs into firewood, and stack the firewood for drying.
7. Document Your Progress: Keep a record of your projects and experiments. Note what works well and what doesn’t. This will help you improve your skills and knowledge over time.

By following these steps, you can transform your Stihl MS170 into a powerful and efficient tool for all your wood processing needs. Remember, consistent maintenance and a sharp chain are the keys to success. Now, get out there and start cutting!

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