Stihl MS 170 Replacement Chain Guide (5 Pro Tips For Durability)

Let’s face it: a dull chain on your Stihl MS 170 is like trying to cut butter with a spoon. It’s frustrating, inefficient, and potentially dangerous. But before you resign yourself to constantly buying new chains, I’m going to share a few pro tips that can significantly extend the life of your Stihl MS 170 replacement chain. These aren’t just generic tips; they are born from years of personal experience in the woods, working with various types of wood, and understanding the nuances of chainsaw maintenance.

Stihl MS 170 Replacement Chain Guide: 5 Pro Tips for Durability

The Stihl MS 170 is a popular choice for homeowners and light-duty users due to its affordability and ease of use. However, its smaller engine and lighter construction mean the chain is more susceptible to wear and tear. This guide is designed to help you maximize the lifespan of your Stihl MS 170 replacement chain, saving you money and ensuring safer, more efficient cutting.

1. Understanding Your Wood: A Crash Course in Wood Anatomy and Properties

Before you even think about firing up your chainsaw, understanding the wood you’re cutting is paramount. Not all wood is created equal, and knowing the difference between hardwood and softwood, as well as the moisture content, can drastically impact chain wear.

Hardwood vs. Softwood: The Great Divide

Hardwoods: Typically deciduous trees (lose their leaves annually), like oak, maple, and hickory. These are denser and more abrasive, meaning they will dull your chain faster. They also tend to have more complex grain patterns, which can cause the chain to bind or kickback if you’re not careful.
Softwoods: Usually coniferous trees (evergreens), like pine, fir, and spruce. These are less dense and easier to cut, but they can still contain resins and pitch that can gum up your chain.

My Personal Experience: I once spent an entire day cutting seasoned oak for firewood. By the end of the day, my chain was significantly duller than if I had been cutting pine. The difference was night and day. This experience taught me the importance of adjusting my cutting technique and sharpening frequency based on the type of wood I was working with.

The Moisture Content Factor: Wet vs. Dry

Wet Wood (Green Wood): Wood that has recently been cut and still contains a high amount of moisture. While it can be easier to cut in some ways, the moisture can cause the chain to rust faster and the sawdust to clump up, increasing friction.
Dry Wood (Seasoned Wood): Wood that has been allowed to dry for a period of time, reducing its moisture content. Dry wood is generally harder to cut, but it’s less likely to cause rust or gumming.

Data Point: Freshly cut wood can have a moisture content of 50% or higher, while seasoned firewood should ideally be below 20%. This difference in moisture content significantly affects the cutting resistance and, consequently, the wear on your chain.

Wood Science Insight: Cellulose, Lignin, and Abrasion

The hardness and abrasiveness of wood are primarily determined by its cellular structure and the presence of compounds like lignin and silica. Lignin, a complex polymer, provides rigidity to the cell walls, while silica, found in some hardwoods, acts as an abrasive.

Cellulose: The main structural component of wood, cellulose fibers provide strength and flexibility.
Lignin: Binds the cellulose fibers together, adding rigidity and hardness to the wood. Higher lignin content generally means harder wood.
Silica: Abrasive particles found in some wood species, particularly those grown in sandy soils. These particles can rapidly dull chainsaw chains.

Practical Tip: When cutting unknown wood, pay attention to the sawdust. If it’s gritty or contains small particles, it’s likely that the wood contains silica or other abrasive compounds. Sharpen your chain more frequently when cutting this type of wood.

2. Chain Selection and Installation: Matching the Right Chain to the Job

Choosing the correct replacement chain for your Stihl MS 170 is crucial for both performance and longevity. Using the wrong chain can lead to poor cutting efficiency, increased wear, and even damage to your chainsaw.

Understanding Chain Specifications

Pitch: The distance between three consecutive rivets divided by two. The Stihl MS 170 typically uses a 3/8″ low-profile pitch.
Gauge: The thickness of the drive links that fit into the guide bar groove. The Stihl MS 170 usually uses a .050″ gauge.
Drive Link Count: The number of drive links on the chain. This is specific to the length of the guide bar.

Data Point: Using the wrong pitch or gauge can cause the chain to bind in the guide bar, leading to premature wear and potential kickback. Always consult your chainsaw’s manual or the Stihl website to determine the correct chain specifications for your MS 170.

Chain Types: Which One is Right for You?

Low-Profile Chains: Designed for smaller chainsaws like the MS 170. They have a smaller cutter and are less prone to kickback.
Full-Chisel Chains: Offer faster cutting but are more aggressive and require more skill to use safely. Not generally recommended for the MS 170 unless you’re experienced.
Semi-Chisel Chains: A good compromise between cutting speed and durability. They’re more forgiving than full-chisel chains and can handle dirty wood better.

Recommendation: For most users of the Stihl MS 170, a low-profile or semi-chisel chain is the best choice. They offer a good balance of cutting performance and durability, and they’re less prone to kickback.

Proper Chain Installation: Avoiding Common Mistakes

Direction: Ensure the chain is installed with the cutters facing in the correct direction (they should point forward at the top of the guide bar).
Tension: Adjust the chain tension so that it can be pulled away from the guide bar slightly (about 1/8 inch) but still fits snugly in the groove.
Lubrication: Always fill the oil reservoir before starting the chainsaw. Proper lubrication is essential for reducing friction and extending chain life.

Personal Story: I once installed a chain backward on my chainsaw (yes, even experienced users make mistakes!). The result was a lot of noise, vibration, and absolutely no cutting. It was a humbling reminder to always double-check my work.

3. Sharpening Techniques: Keeping Your Chain Razor Sharp

A sharp chain is not only more efficient but also safer. A dull chain requires more force to cut, increasing the risk of kickback and operator fatigue. Regular sharpening is the key to maintaining a sharp chain and extending its lifespan.

The Importance of Regular Sharpening

Reduced Wear: A sharp chain cuts cleanly, reducing friction and heat buildup. This minimizes wear on the chain, guide bar, and sprocket.
Improved Cutting Efficiency: A sharp chain cuts faster and requires less effort, saving you time and energy.
Increased Safety: A sharp chain is less likely to kickback or bind, reducing the risk of accidents.

Data Point: A dull chain can increase cutting time by as much as 50% and fuel consumption by 20%. Regular sharpening can significantly improve your chainsaw’s performance and efficiency.

Sharpening Tools: Choosing the Right Equipment

Round File and File Guide: The most common method for sharpening chainsaw chains. A file guide helps you maintain the correct angle and depth.
Electric Chain Sharpener: A faster and more precise method for sharpening chains. Ideal for users who sharpen chains frequently.
Grinding Stone: Can be used to remove significant damage or reshape cutters. Requires more skill and care to avoid overheating the chain.

Recommendation: For occasional users of the Stihl MS 170, a round file and file guide are sufficient. For frequent users, an electric chain sharpener can save time and effort.

The Sharpening Process: Step-by-Step Guide

Secure the Chain: Use a vise or clamp to hold the chain securely in place.
Identify the Correct File Size: The Stihl MS 170 typically uses a 5/32″ round file.
Use a File Guide: Place the file guide on the chain, aligning it with the cutter.
File at the Correct Angle: Maintain the correct filing angle (typically 25-30 degrees) and depth.
File Each Cutter Evenly: File each cutter with the same number of strokes to ensure consistent sharpness.
Lower the Depth Gauges: After sharpening, use a flat file and depth gauge tool to lower the depth gauges (rakers) to the correct height.

Practical Tip: Always file from the inside of the cutter to the outside. This helps to create a clean, sharp edge.

Sharpening Frequency: Knowing When to Sharpen

Visual Inspection: Look for dull or rounded cutters.
Cutting Performance: If the chain is cutting slowly or requires excessive force, it’s time to sharpen.
Sawdust: If the sawdust is fine and powdery instead of coarse and stringy, the chain is likely dull.
After Contact with Dirt or Metal: Sharpen immediately after the chain comes into contact with dirt, rocks, or metal.

Rule of Thumb: Sharpen your chain after every few tanks of fuel, or more frequently if you’re cutting dirty or abrasive wood.

4. Lubrication: The Lifeblood of Your Chain

Proper lubrication is absolutely critical for extending the life of your Stihl MS 170 replacement chain. Without adequate lubrication, the chain will overheat, causing excessive wear and potentially leading to premature failure.

The Role of Chain Oil

Reduces Friction: Chain oil creates a thin film between the chain and the guide bar, reducing friction and heat buildup.
Removes Debris: Chain oil helps to flush away sawdust and other debris, preventing them from clogging the chain and guide bar.
Protects Against Rust: Chain oil forms a protective barrier against moisture, preventing rust and corrosion.

Data Point: A chainsaw chain can reach temperatures of over 200°F (93°C) during operation. Proper lubrication can reduce this temperature by as much as 50%, significantly extending chain life.

Choosing the Right Chain Oil

Bar and Chain Oil: Specifically formulated for chainsaw chains and guide bars. Contains additives to reduce wear and improve adhesion.
Vegetable-Based Oil: An environmentally friendly alternative to petroleum-based oil. Biodegradable and less harmful to the environment.
Used Motor Oil: Not recommended. Used motor oil can contain contaminants that can damage the chain and guide bar.

Recommendation: Use a high-quality bar and chain oil specifically designed for chainsaws. If you’re concerned about the environment, consider using a vegetable-based oil.

Maintaining Proper Lubrication

Check the Oil Level: Always check the oil reservoir before starting the chainsaw and refill as needed.
Adjust the Oil Flow: Adjust the oil flow rate to match the cutting conditions. Increase the flow rate when cutting hard or dry wood.
Clean the Oiler: Regularly clean the oiler to ensure proper oil flow.
Inspect the Guide Bar: Check the guide bar for wear and damage. Replace the guide bar if it’s worn or damaged.

Personal Tip: I always carry an extra bottle of chain oil with me when I’m working in the woods. Running out of oil in the middle of a job can be a major inconvenience.

Understanding Oil Viscosity and Temperature

The viscosity of chain oil plays a crucial role in its performance, especially under varying temperature conditions.

Viscosity: A measure of a fluid’s resistance to flow. Higher viscosity oils are thicker and flow more slowly, while lower viscosity oils are thinner and flow more easily.
Temperature: Temperature affects oil viscosity. As temperature increases, oil viscosity decreases (it becomes thinner). As temperature decreases, oil viscosity increases (it becomes thicker).

Practical Implication: In cold weather, use a lower viscosity chain oil to ensure proper flow and lubrication. In hot weather, use a higher viscosity oil to prevent the oil from thinning out too much and losing its lubricating properties.

5. Guide Bar and Sprocket Maintenance: The Unsung Heroes

While the chain gets most of the attention, the guide bar and sprocket play equally important roles in the overall performance and longevity of your Stihl MS 170. Neglecting these components can lead to premature chain wear and even damage to your chainsaw.

Guide Bar Maintenance

Cleaning: Regularly clean the guide bar groove to remove sawdust and debris. Use a guide bar cleaner or a small screwdriver.
Filing: Remove any burrs or imperfections from the guide bar rails using a flat file.
Truing: Check the guide bar for straightness. If it’s bent or warped, it needs to be trued or replaced.
Lubrication: Apply grease to the guide bar sprocket (if equipped) to keep it lubricated.

Data Point: A worn or damaged guide bar can increase chain wear by as much as 30%. Regular maintenance can significantly extend the life of your guide bar and chain.

Sprocket Maintenance

Inspection: Regularly inspect the sprocket for wear and damage. Look for worn teeth or cracks.
Replacement: Replace the sprocket when it shows signs of wear. A worn sprocket can damage the chain and reduce cutting efficiency.
Lubrication: Apply grease to the sprocket bearing to keep it lubricated.

Practical Tip: Rotate the guide bar every time you replace the chain. This helps to distribute wear evenly and extend the life of the guide bar.

Diagnosing Common Guide Bar Issues

Uneven Rail Wear: Indicates improper chain tension or filing technique.
Burrs on Rails: Caused by contact with hard objects or improper chain sharpening.
Pinched Guide Bar: Occurs when the chain is forced into a narrow cut, causing the rails to pinch together.
Warped Guide Bar: Can result from overheating or improper storage.

Troubleshooting Tip: If you notice any of these issues, address them promptly to prevent further damage to your chain and chainsaw.

Bonus Tip: Storage Matters!

How you store your chainsaw when it’s not in use can also impact the life of your chain.

Clean the Chain and Guide Bar: Before storing your chainsaw, thoroughly clean the chain and guide bar to remove sawdust and debris.
Apply Chain Oil: Apply a light coat of chain oil to the chain and guide bar to prevent rust.
Store in a Dry Place: Store your chainsaw in a dry place to prevent rust and corrosion.
Use a Guide Bar Cover: Use a guide bar cover to protect the chain and guide bar from damage.

Personal Experience: I once left my chainsaw outside in the rain for a week. When I went to use it, the chain was completely rusted and the guide bar was corroded. It was a costly mistake that I won’t make again.

Project Planning and Execution: Putting it All Together

Now that you have a solid understanding of chain maintenance, let’s talk about how to apply these tips in your wood processing projects.

Assessing the Job

Before you start cutting, take some time to assess the job. Consider the following factors:

Type of Wood: Identify the type of wood you’ll be cutting (hardwood vs. softwood).
Moisture Content: Determine the moisture content of the wood (wet vs. dry).
Cutting Conditions: Assess the cutting conditions (clean vs. dirty, level ground vs. uneven terrain).

Planning Your Approach

Based on your assessment, develop a plan for how you’ll approach the job. Consider the following factors:

Chain Selection: Choose the appropriate chain for the type of wood and cutting conditions.
Sharpening Frequency: Plan to sharpen your chain regularly, based on the type of wood and cutting conditions.
Lubrication: Ensure you have an adequate supply of chain oil and adjust the oil flow rate as needed.
Safety Precautions: Take all necessary safety precautions, including wearing appropriate personal protective equipment (PPE).

Executing the Plan

Follow your plan carefully, paying attention to the following details:

Cutting Technique: Use proper cutting techniques to minimize wear on the chain and guide bar.
Sharpening: Sharpen your chain regularly, using the correct tools and techniques.
Lubrication: Maintain proper lubrication throughout the job.
Maintenance: Regularly inspect and maintain the guide bar and sprocket.

Case Study: Firewood Preparation Project

I recently completed a firewood preparation project that involved cutting down several trees and splitting the wood into manageable pieces. By following the tips outlined in this guide, I was able to significantly extend the life of my chainsaw chain and complete the project efficiently and safely.

Wood Type: A mix of oak (hardwood) and pine (softwood).
Moisture Content: Freshly cut (wet).
Cutting Conditions: Clean, level ground.
Chain Selection: Semi-chisel chain.
Sharpening Frequency: Every two tanks of fuel.
Lubrication: High-quality bar and chain oil.

Results: I was able to cut approximately 10 cords of firewood with only one chain replacement. This was significantly better than my previous experiences, where I typically had to replace the chain every 5 cords.

Firewood Seasoning Techniques and Safety Considerations

Once you’ve processed your wood, proper seasoning is crucial for maximizing its fuel value and reducing smoke.

The Science of Seasoning

Seasoning firewood involves reducing its moisture content to around 20% or less. This process increases its heating value and reduces the amount of smoke produced when burned.

Moisture Content Dynamics: As wood dries, water evaporates from the cell walls, causing the wood to shrink and crack.
Ideal Moisture Content: Firewood with a moisture content of 15-20% burns most efficiently.
Consequences of Burning Wet Wood: Burning wet wood produces less heat, more smoke, and can lead to creosote buildup in your chimney.

Seasoning Methods

Air Drying: The most common method, involving stacking the wood in a well-ventilated area and allowing it to dry naturally.
Kiln Drying: A faster method, using a kiln to dry the wood under controlled conditions.
Solar Drying: Using a solar kiln to harness the sun’s energy to dry the wood.

Air Drying Best Practices

Stacking: Stack the wood in a single row, with gaps between each piece to allow for air circulation.
Elevation: Elevate the wood off the ground to prevent moisture from wicking up from the soil.
Sun Exposure: Choose a location with good sun exposure to speed up the drying process.
Covering: Cover the top of the stack to protect the wood from rain and snow, but leave the sides open for ventilation.

Safety Considerations

Stack Stability: Ensure the wood stack is stable and won’t collapse.
Pest Control: Take measures to prevent insect infestations, such as using insecticides or removing bark.
Fire Hazards: Keep the wood stack away from flammable materials and sources of ignition.

Logging Tool Selection and Maintenance Best Practices

Beyond the chainsaw, several other logging tools can enhance your efficiency and safety.

Essential Logging Tools

Felling Axe: Used for felling trees and splitting small logs.
Splitting Maul: Used for splitting larger logs.
Wedges: Used to prevent trees from pinching the saw during felling.
Cant Hook: Used to roll and position logs.
Measuring Tape: Used to measure log lengths.

Tool Maintenance

Sharpening: Keep all cutting tools sharp for optimal performance.
Cleaning: Clean tools after each use to remove dirt and debris.
Lubrication: Lubricate moving parts to prevent rust and corrosion.
Storage: Store tools in a dry place to protect them from the elements.

Tool Safety

Proper Use: Use each tool for its intended purpose.
PPE: Wear appropriate personal protective equipment (PPE), including safety glasses, gloves, and steel-toed boots.
Awareness: Be aware of your surroundings and potential hazards.

Concluding Thoughts: Chainsaw Longevity Through Proactive Care

Extending the life of your Stihl MS 170 replacement chain is not just about saving money; it’s about improving your efficiency, enhancing your safety, and ultimately, enjoying your time in the woods. By understanding the wood you’re cutting, selecting the right chain, sharpening it regularly, maintaining proper lubrication, and caring for your guide bar and sprocket, you can significantly extend the life of your chain and get the most out of your chainsaw.

Remember, proactive maintenance is key. Don’t wait until your chain is completely dull or damaged before taking action. Regular inspection, sharpening, and lubrication will help you keep your chain in top condition and prevent costly repairs.

So, the next time you’re getting ready to fire up your Stihl MS 170, take a few extra minutes to inspect your chain and make sure it’s properly sharpened and lubricated. Your chain (and your wallet) will thank you for it. Now, get out there and make some sawdust!