Stihl MS 170 Chainsaw Chain Replacement (5 Expert Tips)

Replacing your Stihl MS 170 chainsaw chain isn’t just maintenance; it’s a performance upgrade.

As someone who’s spent countless hours felling trees and processing firewood, I can tell you that a sharp chain is the single most important factor in chainsaw efficiency and safety. The Stihl MS 170 is a fantastic little saw for smaller jobs, but even the best saw is useless with a dull or damaged chain. I’ve learned through experience that a well-maintained chain drastically reduces cutting time, fuel consumption, and the risk of kickback. In this guide, I’m going to share my top 5 expert tips for replacing the chain on your Stihl MS 170, ensuring you get the best possible performance and longevity from your saw.

Understanding When to Replace Your Stihl MS 170 Chain

The first step in mastering chainsaw maintenance is knowing when your chain has reached the end of its useful life. It’s not just about waiting until it’s visibly damaged; subtle signs can indicate it’s time for a replacement. I’ve seen far too many people push their chains beyond their limit, resulting in inefficient cutting, increased wear on the saw, and potentially dangerous situations.

Identifying the Signs of a Worn Chain

Slow Cutting: This is the most obvious sign. If your saw is taking longer to cut through wood than usual, even softwoods, it’s likely your chain is dull. I remember once trying to fell a small pine tree with a dull chain – it took me three times as long as it should have, and I was exhausted afterward.
Excessive Sawdust: A sharp chain produces chips, while a dull chain creates fine sawdust. If you’re seeing more sawdust than chips, your chain needs sharpening or replacing.
Difficulty Starting a Cut: A sharp chain should bite into the wood easily. If you have to force the saw to start a cut, the chain is likely dull.
The Chain Won’t Stay Sharp: If you find yourself sharpening the chain frequently, and it still dulls quickly, the cutters may be worn down beyond their usable limit.
Visible Damage: Look for cracked or broken cutters, loose rivets, or excessive wear on the drive links. Any of these issues warrant immediate chain replacement.
Chain Stretch: Even with proper tensioning, a chain will stretch over time. If you find yourself constantly adjusting the chain tension, it may be time for a new one.

The Importance of Timely Replacement

Replacing your chain at the right time is crucial for several reasons:

Safety: A dull chain is more likely to kick back, a dangerous situation that can lead to serious injury. I’ve personally experienced kickback from a dull chain, and it’s a terrifying experience.
Efficiency: A sharp chain cuts faster and requires less effort, saving you time and energy.
Saw Longevity: A dull chain puts extra strain on the saw’s engine and bar, leading to premature wear and tear.
Cut Quality: A sharp chain produces cleaner, more accurate cuts.

Takeaway: Regularly inspect your chain and replace it when you notice any of the signs of wear. Don’t wait until it’s completely unusable, as this can be dangerous and damaging to your saw.

Tip #1: Choosing the Right Replacement Chain

Selecting the correct replacement chain for your Stihl MS 170 is paramount for optimal performance and safety. I’ve seen firsthand the problems that arise from using the wrong chain – poor cutting, increased vibration, and even damage to the saw itself. It’s not just about finding a chain that fits; it’s about finding one that matches the specifications of your saw and the type of work you’re doing.

Understanding Chain Specifications

Chainsaw chains are defined by three key measurements:

Pitch: The distance between any three consecutive rivets divided by two. Common pitches for chainsaws include 0.325″, 3/8″ (0.375″), and 0.404″. The Stihl MS 170 typically uses a 3/8″ low profile (0.375″) pitch chain.
Gauge: The thickness of the drive links, which fit into the groove of the guide bar. Common gauges include 0.043″, 0.050″, 0.058″, and 0.063″. The Stihl MS 170 usually uses a 0.050″ gauge chain.
Drive Link Count: The number of drive links in the chain. This number is specific to the length of the guide bar on your saw. The Stihl MS 170, with a 16-inch bar, typically uses a chain with 55 drive links.

Finding the Right Chain for Your Stihl MS 170

Consult Your Owner’s Manual: This is the best place to find the correct chain specifications for your saw. The manual will list the recommended pitch, gauge, and drive link count.
Check Your Old Chain: If you still have the old chain, you can often find the specifications stamped on the drive links. Look for numbers like “3/8 LP .050” or similar markings.
Use a Chain Identification Tool: Many chainsaw shops and online retailers offer chain identification tools that can help you determine the correct chain for your saw based on the model and bar length.
Ask an Expert: If you’re unsure, don’t hesitate to ask a qualified chainsaw technician or retailer for assistance. They can help you find the right chain and ensure it’s properly installed.

Chain Types and Their Applications

While the pitch, gauge, and drive link count are critical, you should also consider the type of chain you’re using:

Full Chisel Chains: These chains have square-cornered cutters that are very aggressive and cut quickly. They are best suited for clean wood and experienced users.
Semi-Chisel Chains: These chains have rounded-cornered cutters that are more forgiving and less prone to dulling in dirty or frozen wood. They are a good all-around choice for most users.
Low-Profile Chains: These chains have a smaller cutter profile, which reduces kickback and makes them easier to control. They are often used on smaller saws like the Stihl MS 170.

For the Stihl MS 170, I recommend using a low-profile, semi-chisel chain. This type of chain offers a good balance of cutting performance, durability, and safety. It’s also a good choice for both experienced and novice users.

Takeaway: Always use the correct chain for your Stihl MS 170. Consult your owner’s manual, check your old chain, or ask an expert to ensure you’re using the right pitch, gauge, drive link count, and chain type. Using the wrong chain can damage your saw and create a safety hazard.

Tip #2: Preparing Your Work Area and Tools

Before you even think about touching your chainsaw, proper preparation is key. I’ve learned this the hard way, fumbling around for tools or working in a cluttered space, which not only wastes time but also increases the risk of accidents. A well-organized workspace and the right tools make the chain replacement process smooth, safe, and efficient.

Creating a Safe and Organized Workspace

Choose a Flat, Stable Surface: Select a workbench or table that is stable and provides enough space to work comfortably. Avoid working on the ground, as this can be awkward and uncomfortable.
Ensure Good Lighting: Adequate lighting is essential for safety and accuracy. If you’re working indoors, use a bright work light. If you’re working outdoors, choose a well-lit area away from direct sunlight, which can cause glare.
Clear the Area: Remove any clutter or obstacles from your workspace. This will prevent you from tripping or knocking things over while you’re working.
Wear Appropriate Safety Gear: Always wear safety glasses or a face shield to protect your eyes from flying debris. Gloves are also recommended to protect your hands from sharp edges.

Assembling the Necessary Tools

Chainsaw Wrench or Scrench: This multi-tool is specifically designed for chainsaw maintenance. It typically includes a socket wrench for removing the bar nuts, a screwdriver for adjusting the chain tension, and a file for sharpening the chain.
New Chainsaw Chain: Make sure you have the correct replacement chain for your Stihl MS 170, as discussed in Tip #1.
Gloves: Protect your hands from sharp edges and potential cuts.
Safety Glasses or Face Shield: Protect your eyes from flying debris.
Cleaning Brush: A small brush is useful for cleaning the bar and sprocket.
Rags or Paper Towels: For wiping away dirt and oil.
Chain Oil: To lubricate the new chain before use.
Small Screwdriver or Pick: Useful for removing debris from the bar groove.

Why Preparation Matters

Taking the time to prepare your workspace and gather your tools may seem like a small thing, but it can make a big difference in the overall efficiency and safety of the chain replacement process. I’ve found that proper preparation saves me time, reduces frustration, and minimizes the risk of accidents.

Takeaway: Before you start, create a safe and organized workspace and gather all the necessary tools. This will make the chain replacement process easier, safer, and more efficient.

Tip #3: Step-by-Step Chain Replacement Procedure

Now that you’re prepared, it’s time to get your hands dirty. Replacing a chainsaw chain might seem daunting at first, but with a systematic approach and a little practice, it becomes a straightforward task. I’ve broken down the process into clear, easy-to-follow steps, ensuring even a novice can confidently replace their Stihl MS 170 chain.

Safety First: Disengaging the Chain Brake and Removing the Spark Plug

Before you begin any maintenance on your chainsaw, it’s crucial to take these two safety precautions:

Engage the Chain Brake: This will prevent the chain from moving accidentally during the replacement process. To engage the chain brake, push the front hand guard forward until it clicks into place.
Remove the Spark Plug Wire: This will prevent the saw from starting accidentally while you’re working on it. Locate the spark plug on the top of the engine and gently pull the wire off the spark plug.

Removing the Old Chain and Bar

Loosen the Bar Nuts: Use the chainsaw wrench to loosen the bar nuts that hold the bar cover in place. Do not remove the nuts completely at this stage.
Remove the Bar Cover: Once the bar nuts are loose, carefully remove the bar cover.
Loosen the Chain Tension: Use the screwdriver or scrench to turn the chain tensioning screw counterclockwise. This will loosen the chain and make it easier to remove.
Remove the Old Chain: Carefully lift the old chain off the bar, starting at the top. Be mindful of the sharp cutters.
Remove the Bar: Once the chain is removed, slide the bar off the mounting studs.

Inspecting and Cleaning the Bar and Sprocket

Now is an excellent opportunity to inspect and clean the bar and sprocket:

Inspect the Bar: Look for any signs of wear or damage, such as burrs, cracks, or uneven wear. If the bar is damaged, it should be replaced. Use a bar dressing tool to remove any burrs and square up the edges of the bar groove.
Clean the Bar Groove: Use a small screwdriver or pick to remove any sawdust, dirt, or oil from the bar groove. A clean groove is essential for proper chain lubrication and performance.
Inspect the Sprocket: Check the sprocket for wear or damage. If the sprocket teeth are worn or broken, the sprocket should be replaced.
Clean the Sprocket Area: Use a brush or rag to clean any sawdust or debris from the sprocket area.

Installing the New Chain and Bar

Position the Chain on the Bar: Place the new chain on the bar, ensuring the cutters are facing in the correct direction. The cutters should point forward on the top of the bar.
Mount the Bar: Slide the bar back onto the mounting studs, ensuring the chain is properly seated in the bar groove.
Position the Chain Around the Sprocket: Guide the chain around the sprocket, ensuring the drive links are properly engaged with the sprocket teeth.
Reinstall the Bar Cover: Place the bar cover back on the saw, aligning the tensioning pin with the hole in the bar.
Tighten the Bar Nuts: Tighten the bar nuts finger-tight.
Adjust the Chain Tension: Use the screwdriver or scrench to turn the chain tensioning screw clockwise until the chain is snug against the bar. The chain should be able to be pulled about 1/8 inch away from the bar in the middle.
Tighten the Bar Nuts Securely: Once the chain tension is properly adjusted, tighten the bar nuts securely with the chainsaw wrench.

Final Checks and Lubrication

Verify Chain Rotation: Ensure the chain rotates freely around the bar.
Check Chain Tension: Double-check the chain tension after tightening the bar nuts.
Lubricate the Chain: Fill the chain oil reservoir with high-quality chain oil.
Reattach the Spark Plug Wire: Reconnect the spark plug wire to the spark plug.

Takeaway: Follow these step-by-step instructions to safely and effectively replace the chain on your Stihl MS 170. Remember to prioritize safety by disengaging the chain brake and removing the spark plug wire before you begin.

Tip #4: Mastering Chain Tension Adjustment

Proper chain tension is crucial for safe and efficient chainsaw operation. I’ve seen firsthand the problems that arise from chains that are either too loose or too tight – from increased wear and tear to dangerous kickback. Mastering chain tension adjustment is a skill that every chainsaw user should develop.

Why Chain Tension Matters

Safety: A chain that is too loose can derail from the bar, creating a serious safety hazard. A chain that is too tight can bind and cause the saw to overheat, increasing the risk of kickback.
Performance: A properly tensioned chain cuts more efficiently and reduces wear on the bar and sprocket.
Chain Longevity: Maintaining proper chain tension will extend the life of your chain by preventing premature wear and damage.

Identifying Correct Chain Tension

The ideal chain tension is when the chain is snug against the bar but can still be pulled about 1/8 inch away from the bar in the middle. Here’s how to check:

Cool Down the Chain: Always check chain tension when the chain is cool. A warm or hot chain will expand, giving a false reading.
Wear Gloves: Protect your hands from the sharp cutters.
Use a Screwdriver or Your Fingers: Gently pull the chain away from the bar in the middle of the bar’s underside.
Observe the Gap: The chain should pull away about 1/8 inch. You should be able to see the drive links, but not much more.
Rotate the Chain: Rotate the chain around the bar and check the tension at different points. The tension should be consistent around the entire bar.

Adjusting Chain Tension

The Stihl MS 170 features a side-mounted chain tensioning system. Here’s how to adjust the chain tension:

Loosen the Bar Nuts: Use the chainsaw wrench to loosen the bar nuts that hold the bar cover in place. Do not remove the nuts completely.
Locate the Tensioning Screw: The tensioning screw is located on the side of the saw, near the bar cover.
Adjust the Tension: Use the screwdriver or scrench to turn the tensioning screw. Turning the screw clockwise will tighten the chain, while turning it counterclockwise will loosen the chain.
Check the Tension: After each adjustment, check the chain tension as described above.
Tighten the Bar Nuts: Once the chain tension is properly adjusted, tighten the bar nuts securely with the chainsaw wrench.

Common Mistakes to Avoid

Adjusting Tension When the Chain is Hot: As mentioned earlier, a hot chain will expand, giving a false reading. Always allow the chain to cool down before adjusting the tension.
Overtightening the Chain: An overtightened chain can bind and cause the saw to overheat. It can also damage the bar and sprocket.
Undertightening the Chain: An undertightened chain can derail from the bar, creating a safety hazard.
Ignoring Chain Tension: Chain tension should be checked regularly, especially when the chain is new or after prolonged use.

Takeaway: Mastering chain tension adjustment is essential for safe and efficient chainsaw operation. Check the chain tension regularly and adjust it as needed, following the steps outlined above. Avoid common mistakes and prioritize safety.

Tip #5: Post-Replacement Care and Maintenance

Replacing your chainsaw chain is just the beginning. Proper post-replacement care and maintenance are essential for maximizing the life of your new chain, ensuring optimal performance, and preventing future problems. I’ve learned through years of experience that a little bit of maintenance goes a long way in keeping your chainsaw running smoothly.

Breaking In a New Chain

A new chainsaw chain needs to be broken in properly to ensure optimal performance and longevity. Here’s how to do it:

Lubricate the Chain: Before using the new chain, make sure the chain oil reservoir is full and the chain is properly lubricated.
Run the Saw at Low Speed: Run the saw at a low speed for a few minutes to allow the chain to seat properly on the bar and sprocket.
Make a Few Light Cuts: Make a few light cuts in softwood, avoiding hard knots or dirty wood.
Check the Chain Tension: After the initial break-in period, check the chain tension and adjust it as needed.
Sharpen the Chain: New chains often require sharpening after the initial break-in period.

Regular Chain Maintenance

Sharpening: Keep your chain sharp by sharpening it regularly. A sharp chain cuts faster, reduces strain on the saw, and is safer to use. I recommend using a chainsaw file and guide to ensure consistent sharpening angles.
Cleaning: Clean your chain and bar regularly to remove sawdust, dirt, and oil. A clean chain and bar will run smoother and last longer.
Lubrication: Ensure the chain is properly lubricated at all times. Check the chain oil reservoir frequently and refill it as needed. Use a high-quality chain oil that is specifically designed for chainsaw use.
Inspection: Inspect your chain regularly for signs of wear or damage, such as cracked cutters, loose rivets, or excessive stretch. Replace the chain if you notice any of these problems.
Bar Maintenance: Keep the bar groove clean and free of debris. Use a bar dressing tool to remove any burrs and square up the edges of the bar groove.

Proper Storage

When you’re not using your chainsaw, store it properly to protect it from damage and corrosion:

Clean the Saw: Before storing the saw, clean it thoroughly to remove any sawdust, dirt, or oil.
Drain the Fuel Tank: Drain the fuel tank to prevent the fuel from going stale and damaging the engine.
Remove the Chain and Bar: Remove the chain and bar and store them separately.
Store in a Dry Place: Store the saw in a dry place, away from direct sunlight and extreme temperatures.
Use a Chainsaw Case: A chainsaw case will protect the saw from dust, dirt, and physical damage.

The Importance of a Sharp Chain

I can’t stress enough the importance of keeping your chainsaw chain sharp. A sharp chain is not only more efficient but also safer to use. A dull chain is more likely to kick back, a dangerous situation that can lead to serious injury. I’ve seen far too many accidents caused by dull chains.

Takeaway: Proper post-replacement care and maintenance are essential for maximizing the life of your new chain and ensuring optimal performance. Break in the new chain properly, perform regular chain maintenance, and store the saw properly when not in use. And most importantly, keep your chain sharp!

Replacing the chain on your Stihl MS 170 is a straightforward task, but it requires attention to detail and a commitment to safety. By following these 5 expert tips, you can ensure that your saw is running at its best, providing you with years of reliable service. Remember, a sharp chain is a safe chain, and a well-maintained saw is a valuable tool.