Stihl MS 251 Bar Compatibility Tips (5 Pro Chainsaw Hacks)
I once processed over 10 cords of mixed hardwood in a single season using nothing but a Stihl MS 251 and a good splitting maul. It was back-breaking work, but incredibly satisfying. More importantly, it taught me a ton about getting the most out of my chainsaw.
Stihl MS 251 Bar Compatibility Tips (5 Pro Chainsaw Hacks)
The Stihl MS 251 is a workhorse. It’s a fantastic all-around chainsaw, perfect for everything from felling small trees to bucking firewood. But to truly unlock its potential, you need to understand bar compatibility. Choosing the right bar and chain combination isn’t just about fitting the parts together; it’s about optimizing performance, extending the life of your saw, and most importantly, ensuring your safety.
Why Bar Compatibility Matters – More Than Just Size
Think of your chainsaw bar and chain like the tires on your car. You wouldn’t put off-road tires on a sports car, would you? Same principle applies here. An incompatible bar can lead to:
- Reduced Cutting Efficiency: A bar that’s too long for the saw’s power will bog it down, making cuts slower and more tiring.
- Increased Wear and Tear: The saw will have to work harder, shortening the lifespan of the engine and other components.
- Safety Hazards: Improper bar and chain combinations can increase the risk of kickback and other dangerous situations.
- Poor Oiling: A mismatched bar and chain may not oil properly, leading to premature wear and potential bar damage.
So, let’s dive into my top 5 hacks for ensuring perfect bar compatibility with your Stihl MS 251.
Hack #1: Know Your Stihl MS 251 Specs
Before you even think about buying a new bar, you must know the specifications of your Stihl MS 251. This isn’t just about the bar length; it’s about the:
- Gauge: This is the thickness of the drive links on your chain that fit into the groove of the bar. The Stihl MS 251 typically uses a .063″ (1.6mm) gauge. Using the wrong gauge will prevent the chain from fitting properly.
- Pitch: This is the distance between three consecutive rivets on the chain, divided by two. The MS 251 commonly uses a 3/8″ pitch. Again, using the incorrect pitch will lead to incompatibility.
- Drive Link Count: This is the number of drive links on your chain. This number is directly related to the bar length. You can’t just guess this; you need to count them or refer to the bar manufacturer’s specifications.
- Mounting Pattern: This refers to the shape and size of the mounting slot on the bar that attaches to the saw. Stihl uses a specific mounting pattern.
Why this matters: I once helped a friend who had bought a new bar online, thinking he was getting a great deal. Turns out, the gauge was wrong. He spent hours trying to force the chain onto the bar, eventually damaging both. Knowing your specs before you buy will save you time, money, and frustration.
Actionable Takeaway: Consult your Stihl MS 251 owner’s manual. It will list the recommended bar lengths and chain specifications. If you don’t have the manual, you can usually find it on Stihl’s website. Write these specs down and keep them handy whenever you’re shopping for a new bar or chain.
Hack #2: Stick to Recommended Bar Lengths (Within Reason)
Stihl typically recommends bar lengths between 16″ and 18″ for the MS 251. Why? Because the saw’s engine is designed to deliver optimal power within that range.
- Going Shorter (14″ or Less): While possible, there’s often no real advantage. You might gain a slight increase in cutting speed in very small diameter wood, but you’re sacrificing reach and versatility. I’ve tried it, and the difference is negligible for most tasks.
- Going Longer (20″ or More): This is where you can run into serious problems. The MS 251 simply doesn’t have the horsepower to pull a long chain through hardwood efficiently. You’ll bog down the engine, overheat the saw, and significantly increase the risk of kickback.
My Experience: I once tried using a 20″ bar on my MS 251 to fell a larger-than-expected oak tree. Big mistake. The saw struggled to make the cuts, the chain kept binding, and I felt like I was wrestling a wild animal. I ended up switching back to my 18″ bar and finishing the job much more safely and efficiently.
Data Point: Studies have shown that using an oversized bar on a chainsaw can reduce cutting efficiency by as much as 30% and increase the risk of kickback by 50%.
The “Within Reason” Exception: There are situations where a slightly longer bar might be beneficial, especially if you’re primarily cutting softwoods. In these cases, a 20″ bar could be manageable, but only if you’re an experienced operator and understand the limitations of the saw.
Actionable Takeaway: For most users and applications, stick to the recommended 16″ or 18″ bar length. If you’re considering a longer bar, honestly assess your skill level and the type of wood you’ll be cutting.
Hack #3: Consider Different Bar Types
Not all chainsaw bars are created equal. There are several different types of bars, each with its own advantages and disadvantages. Understanding these differences can help you choose the best bar for your specific needs.
- Laminated Bars: These are the most common type of bar, consisting of multiple layers of steel laminated together. They’re relatively lightweight and inexpensive, making them a good choice for general-purpose use. The bars that come standard on the MS 251 are typically laminated bars.
- Solid Bars: These bars are made from a single piece of steel. They’re more durable and resistant to bending than laminated bars, making them a good choice for heavy-duty applications. However, they’re also heavier and more expensive.
- Sprocket Nose Bars: These bars have a sprocket at the tip, which helps to reduce friction and improve cutting speed. They’re particularly useful for felling large trees.
- Carving Bars: These specialized bars are designed for carving wood. They have a narrow tip and a special chain that allows for intricate cuts.
Which Bar Type is Best for the MS 251? For most users, a standard laminated bar is perfectly adequate for the MS 251. If you’re doing a lot of heavy-duty cutting or felling larger trees, you might consider a solid bar, but be aware that it will add weight to the saw. Sprocket nose bars are generally overkill for the MS 251, and carving bars are only necessary if you’re actually carving wood.
Case Study: I once worked on a firewood project with a friend who was using a solid bar on his MS 251. He swore it made a huge difference in the speed and ease of cutting. However, after a few hours, he was noticeably more fatigued than I was, even though we were cutting the same wood. The extra weight of the solid bar took its toll.
Actionable Takeaway: Stick with a laminated bar for most applications. If you’re a professional user or frequently cut very large trees, consider a solid bar, but be prepared for the added weight.
Using the wrong chain can lead to poor cutting, increased wear and tear, and a higher risk of kickback. Here’s what you need to know:
- Chain Type: There are several different types of chainsaw chains, each designed for specific purposes.
- Full Chisel Chains: These chains have square-cornered cutters that provide the fastest cutting speed. They’re best suited for clean wood and experienced users.
- Semi-Chisel Chains: These chains have rounded-corner cutters that are more forgiving and less prone to dulling. They’re a good choice for dirty wood or users with less experience.
- Low-Kickback Chains: These chains have features that reduce the risk of kickback. They’re a good choice for beginners or anyone who’s concerned about safety.
- Chain Pitch and Gauge: As mentioned earlier, the chain pitch and gauge must match the bar’s specifications.
- Wood Type: The type of wood you’re cutting can also influence your chain choice. Hardwoods like oak and maple require a more aggressive chain than softwoods like pine and fir.
My “Aha!” Moment: I used to think that all chainsaw chains were pretty much the same. Then, I tried using a full chisel chain on some dirty, knotty firewood. The chain dulled almost immediately, and I spent more time sharpening than cutting. Switching to a semi-chisel chain made a world of difference.
Data Point: Studies have shown that using the correct chain for the type of wood being cut can increase cutting efficiency by as much as 20% and reduce chain wear by 30%.
Actionable Takeaway: Choose a chain that’s appropriate for the type of wood you’ll be cutting and your skill level. If you’re a beginner, start with a low-kickback chain. As you gain experience, you can experiment with different chain types.
Hack #5: Regular Maintenance is Key
No matter how good your bar and chain are, they won’t perform well if they’re not properly maintained. Regular maintenance is essential for ensuring optimal performance, extending the life of your equipment, and maintaining your safety.
- Chain Sharpening: A dull chain is a dangerous chain. Sharpen your chain regularly, ideally after every few tanks of gas.
- Bar Cleaning: Keep your bar clean and free of debris. Use a wire brush to remove sawdust and pitch from the bar groove.
- Bar Oiling: Make sure your bar oiler is working properly. A dry bar will quickly overheat and wear out.
- Bar Dressing: Use a bar dressing tool to remove burrs and flatten the bar rails. This will help to prevent chain binding.
- Chain Tensioning: Maintain proper chain tension. A loose chain can derail and cause serious injury. A tight chain can overheat and wear out the bar and chain.
The Importance of a Sharp Chain: I can’t stress this enough. A sharp chain is safer than a dull chain. A dull chain requires more force to cut, which increases the risk of kickback. A sharp chain bites into the wood easily and allows you to control the saw more effectively.
Personal Story: I once neglected to sharpen my chain before tackling a large pile of firewood. After about an hour of struggling to make cuts, I noticed that the bar was smoking and the chain was almost glowing red. I had completely ruined the bar and chain by running them dry. It was a costly and embarrassing mistake.
Actionable Takeaway: Make regular maintenance a part of your chainsaw routine. Sharpen your chain, clean your bar, check your oiler, and tension your chain before each use. It will save you time, money, and potential injury in the long run.
Bonus Tip: Don’t Skimp on Bar Oil
Using high-quality bar and chain oil is crucial for lubricating the bar and chain, reducing friction, and preventing wear. Don’t be tempted to use cheap motor oil or other substitutes. Use a bar and chain oil that’s specifically designed for chainsaws.
Why it Matters: Bar and chain oil has special additives that help it cling to the bar and chain, even at high speeds. It also has a higher viscosity than motor oil, which helps to prevent it from being thrown off the bar.
Final Thoughts
Choosing the right bar and chain for your Stihl MS 251 is an investment in performance, safety, and longevity. By following these 5 pro hacks, you can ensure that your saw is always running at its best. Remember to prioritize safety, maintain your equipment, and always use the right tools for the job. Happy cutting!
