Stihl MS661 Comparison Guide (5 Key Pro Logging Differences)

Imagine standing in the heart of a dense forest, the air thick with the scent of pine and damp earth. The only sound is the rhythmic chugging of a powerful chainsaw, biting into the massive trunk of a fallen tree. This is my world, a world of timber, torque, and the satisfaction of transforming raw wood into something useful. For years, I’ve relied on Stihl chainsaws, and among them, the MS661 has always been a top contender for heavy-duty logging. But not all MS661s are created equal. There are subtle yet crucial differences that separate a standard model from a true pro logging machine. This guide is born from years of hands-on experience, countless hours spent in the woods, and a deep understanding of what it takes to bring down big timber safely and efficiently. I’m going to break down the five key differences that elevate the MS661 to a professional logging tool, helping you make the right choice for your needs. Whether you’re a seasoned logger or just starting out, this guide will provide valuable insights into maximizing the performance and longevity of your chainsaw.

Stihl MS661 Comparison Guide (5 Key Pro Logging Differences)

The Stihl MS661 is a beast of a chainsaw, but it’s important to understand what sets a ‘pro’ logging version apart from a standard MS661. These differences, while seemingly minor, can significantly impact performance, durability, and ultimately, your productivity in the woods. It’s not just about having a big saw; it’s about having the right big saw.

1. The Powerhead: Engine Tuning and Component Quality

The heart of any chainsaw is its engine, and the MS661 is no exception. While both standard and pro models share the same basic engine design, there are critical differences in the tuning and component quality that impact performance and longevity.

Engine Tuning: Professional loggers often require a chainsaw that can maintain peak performance under prolonged, heavy use. Pro logging MS661s often have slightly different carburetor settings from the factory, optimized for higher RPMs and sustained power output. This might involve richer fuel mixtures to prevent overheating and ensure consistent performance even when buried deep in hardwood. I’ve noticed this difference firsthand when comparing the throttle response and cutting speed of different MS661s under similar load conditions. A pro-tuned saw simply pulls harder and longer.
Component Quality: While Stihl is known for its quality, some pro models might have upgraded components in critical areas like the cylinder, piston, and crankshaft. These upgrades are designed to withstand the increased stress associated with professional logging. For example, a pro model might feature a chrome-plated cylinder for improved wear resistance or a forged crankshaft for increased strength and durability. These differences aren’t always readily apparent but can significantly extend the lifespan of the saw, especially under demanding conditions. I’ve seen standard MS661s develop cylinder scoring after a few years of heavy use, while pro models with upgraded components continue to run strong.
Example: I once worked on a salvage logging operation after a severe windstorm. We were cutting large-diameter, heavily stressed trees, and the standard MS661s struggled to maintain consistent power, often bogging down in the cut. The pro-tuned MS661s, on the other hand, powered through with ease, allowing us to maintain a faster pace and meet our production targets. This experience highlighted the importance of proper engine tuning for demanding logging applications.

2. Bar and Chain Selection: Length, Type, and Gauge

The bar and chain are the cutting interface of the chainsaw, and selecting the right combination is crucial for optimal performance and safety. Pro logging MS661s are typically configured with bars and chains suited for felling large trees and bucking heavy timber.

Bar Length: Professional loggers often require longer bars to handle larger diameter trees. While a standard MS661 might come with a 25-inch or 28-inch bar, pro models are often equipped with 32-inch, 36-inch, or even longer bars. The appropriate bar length depends on the typical tree size in your area. Using a bar that’s too short can be inefficient and potentially dangerous, while a bar that’s too long can be unwieldy and difficult to control.
Chain Type: The type of chain used also plays a significant role in cutting performance. Professional loggers often prefer full-chisel chains for their aggressive cutting action and ability to quickly remove large amounts of wood. However, full-chisel chains require more skill to sharpen and are more prone to kickback. Semi-chisel chains offer a good balance of cutting speed and ease of maintenance, making them a popular choice for all-around logging applications.
Chain Gauge: The chain gauge refers to the thickness of the drive links that fit into the bar groove. Pro logging MS661s often use chains with a larger gauge (e.g., .063″) for increased durability and resistance to stretching. A thicker gauge chain is less likely to break or derail, especially when cutting large, dense hardwoods.
Case Study: In one of my firewood preparation projects, I had to process a large oak tree that had fallen during a storm. Using a standard MS661 with a 20-inch bar, I struggled to make clean cuts through the thick trunk. After switching to a pro-configured MS661 with a 32-inch bar and full-chisel chain, the cutting process became significantly faster and easier. The longer bar allowed me to reach deeper into the trunk, while the aggressive chain quickly removed the wood.

3. Oiling System: Capacity and Adjustability

Proper lubrication is essential for maintaining the health and performance of the bar and chain. A pro logging MS661 typically features an upgraded oiling system with increased capacity and adjustability.

Oil Tank Capacity: Professional loggers often work long hours in remote locations, where refueling can be a challenge. A larger oil tank capacity allows for extended operation without the need to constantly refill the oil. This can significantly improve productivity and reduce downtime.
Adjustable Oil Flow: The ability to adjust the oil flow is crucial for optimizing lubrication based on the bar length, wood type, and cutting conditions. When cutting large, dense hardwoods, a higher oil flow is necessary to prevent the bar and chain from overheating and wearing out prematurely. Conversely, when cutting smaller diameter trees or softer woods, a lower oil flow may be sufficient. Pro logging MS661s often feature an adjustable oil pump that allows the user to fine-tune the oil flow to match the specific needs of the job.
Example: I once worked on a project where we were felling large-diameter Douglas fir trees in steep terrain. The standard MS661s we were using ran out of bar oil much faster than the pro models, forcing us to stop frequently and refill. This not only slowed down our production but also increased the risk of accidents due to fatigue and frustration. The pro models, with their larger oil tanks and adjustable oil flow, allowed us to work longer and more efficiently.

4. Handle and Vibration Dampening: Ergonomics and Comfort

Logging is a physically demanding profession, and the ergonomics of the chainsaw can significantly impact operator fatigue and safety. Pro logging MS661s often feature upgraded handles and vibration dampening systems for improved comfort and control.

Handle Design: The handle design of a pro logging MS661 is typically optimized for comfortable and secure grip, even when wearing gloves. This might involve using a larger diameter handle, adding textured surfaces for improved grip, or incorporating ergonomic features that reduce strain on the hands and wrists.
Vibration Dampening: Prolonged exposure to chainsaw vibration can lead to a condition known as “white finger” or hand-arm vibration syndrome (HAVS), which can cause numbness, tingling, and pain in the fingers and hands. Pro logging MS661s often feature advanced vibration dampening systems that significantly reduce the amount of vibration transmitted to the operator. This might involve using rubber mounts, springs, or other vibration-absorbing materials to isolate the engine and cutting components from the handles.
Personal Story: I remember a time when I was working on a large-scale timber harvest. I was using a standard MS661 with a basic vibration dampening system. After a few days of heavy use, my hands and arms were constantly aching, and I started to experience numbness in my fingers. I switched to a pro logging MS661 with an upgraded vibration dampening system, and the difference was remarkable. The vibration was significantly reduced, and my hands and arms felt much less fatigued at the end of the day. This experience convinced me of the importance of investing in a chainsaw with good ergonomics and vibration dampening.

5. Durability and Serviceability: Construction and Maintenance

A pro logging MS661 is built to withstand the rigors of daily use in demanding environments. This means using high-quality materials, robust construction techniques, and designing the saw for easy maintenance and repair.

Material Selection: Pro logging MS661s often use stronger and more durable materials in critical areas like the crankcase, cylinder head, and clutch housing. This helps to resist damage from impacts, abrasion, and extreme temperatures.
Construction Techniques: The construction of a pro logging MS661 is typically more robust than a standard model. This might involve using thicker castings, reinforced welds, and more durable fasteners. These features help to ensure that the saw can withstand the stresses of heavy use and maintain its structural integrity over time.
Serviceability: Professional loggers need a chainsaw that is easy to maintain and repair in the field. Pro logging MS661s are often designed with easy access to critical components like the air filter, spark plug, and carburetor. This allows for quick and easy maintenance, reducing downtime and keeping the saw running smoothly.
Real-World Example: I once had a standard MS661 that suffered a cracked crankcase after being dropped on a rocky slope. The repair required a complete engine teardown and replacement of the crankcase, which was a time-consuming and expensive process. A pro logging MS661, with its more robust construction, would likely have been able to withstand the impact without suffering such serious damage.

Key Terms and Concepts:

Green Wood vs. Seasoned Wood: Green wood is freshly cut wood with a high moisture content (often above 30%). Seasoned wood has been dried, reducing its moisture content to around 20% or less. Green wood is harder to cut and heavier, while seasoned wood burns more efficiently and produces less smoke.
Felling: The process of cutting down a tree.
Bucking: The process of cutting a felled tree into smaller, manageable lengths.
Limbing: The process of removing the branches from a felled tree.
Kickback: A sudden and dangerous upward or backward motion of the chainsaw bar that can occur when the tip of the bar contacts a solid object.
Chisel Chain: A type of chainsaw chain with square-cornered cutters that provide aggressive cutting action.
Semi-Chisel Chain: A type of chainsaw chain with rounded-corner cutters that offer a balance of cutting speed and ease of maintenance.
Chain Gauge: The thickness of the drive links on a chainsaw chain.
Moisture Content: The amount of water in wood, expressed as a percentage of the wood’s dry weight.

Step-by-Step Guide: Felling a Tree Safely

Felling a tree is a dangerous task that should only be performed by trained professionals. However, understanding the basic steps involved can help you appreciate the skill and knowledge required.

Assess the Tree and Surroundings: Before making any cuts, carefully assess the tree for lean, dead limbs, and other hazards. Clear the area around the tree of obstacles and create a clear escape path.
Determine the Felling Direction: Choose a felling direction that is safe and will minimize damage to surrounding trees and property. Consider the tree’s natural lean, wind direction, and any obstacles in the area.
Make the Notch Cut: The notch cut is a wedge-shaped cut that helps to guide the tree in the desired felling direction. The notch should be about one-third of the tree’s diameter and angled at 45 degrees.
Make the Back Cut: The back cut is a horizontal cut that is made on the opposite side of the tree from the notch cut. The back cut should be slightly above the bottom of the notch cut and should leave a hinge of wood to help control the tree’s fall.
Warn Others and Retreat: Before completing the back cut, warn anyone in the area that the tree is about to fall. Once the back cut is complete, quickly retreat along your escape path, keeping your eye on the falling tree.

Debarking Logs: Techniques and Tools

Debarking logs is the process of removing the bark from the wood. This can be done for aesthetic reasons, to prevent insect infestation, or to speed up the drying process.

Hand Tools: Hand tools like drawknives and spud bars can be used to remove bark from logs. These tools are relatively inexpensive and require no power, but they can be time-consuming and physically demanding to use.
Mechanical Debarkers: Mechanical debarkers use rotating blades or drums to remove bark from logs. These machines are much faster and more efficient than hand tools, but they are also more expensive and require power to operate.

Splitting Firewood: Manual vs. Hydraulic

Splitting firewood can be done manually with an axe or maul, or hydraulically with a log splitter.

Manual Splitting: Manual splitting is a good option for small quantities of firewood or for those who enjoy the physical exercise. However, it can be very tiring and time-consuming, especially when splitting large or knotty logs. A splitting axe is designed with a wider head to split with the grain, while a maul is heavier for more force.
Hydraulic Splitting: Hydraulic log splitters use hydraulic pressure to force a log against a wedge, splitting it in two. These machines are much faster and easier to use than manual splitting, especially for large quantities of firewood. They come in various sizes and power levels, from small electric models for home use to large gas-powered models for commercial operations.

Drying Methods: Air Drying vs. Kiln Drying

Drying firewood is essential for efficient burning and reduced smoke. There are two main methods of drying firewood: air drying and kiln drying.

Air Drying: Air drying involves stacking firewood in a well-ventilated area and allowing it to dry naturally over time. This is the most common and cost-effective method of drying firewood, but it can take several months or even a year for the wood to dry completely. Proper stacking is key – leave space between the logs and rows for airflow.
Kiln Drying: Kiln drying involves placing firewood in a heated chamber to accelerate the drying process. This method can dry firewood in a matter of days or weeks, but it is more expensive than air drying. Kiln-dried firewood typically has a lower moisture content than air-dried firewood, resulting in more efficient burning.

Safety Considerations

Working with chainsaws and wood processing equipment can be dangerous. Always follow these safety precautions:

Wear Appropriate Safety Gear: Always wear a helmet, eye protection, hearing protection, gloves, and chainsaw chaps when operating a chainsaw.
Maintain Your Equipment: Keep your chainsaw and other equipment in good working order. Sharpen the chain regularly and inspect the saw for any damage before each use.
Use Proper Techniques: Use proper felling, bucking, and splitting techniques to avoid accidents.
Be Aware of Your Surroundings: Be aware of your surroundings and watch out for hazards such as overhead power lines, unstable ground, and other people.
Never Work Alone: Always work with a partner or let someone know where you will be working and when you expect to return.

Strategic Advantages of Using a Hydraulic Splitter

Investing in a hydraulic log splitter offers several strategic advantages, especially for those processing large quantities of firewood:

Increased Efficiency: Hydraulic splitters can split logs much faster than manual splitting, allowing you to process more firewood in less time.
Reduced Fatigue: Hydraulic splitters require less physical effort than manual splitting, reducing fatigue and the risk of injury.
Improved Safety: Hydraulic splitters minimize the risk of accidents associated with swinging an axe or maul.
Consistent Results: Hydraulic splitters provide consistent splitting results, ensuring that your firewood is uniform in size and shape.

Costs, Material Specs, Timing Estimates, and Skill Levels

MS661 Cost: The Stihl MS661 typically ranges from $1,200 to $1,500, depending on the configuration and dealer. Pro logging models may command a premium due to upgraded components.
Material Specs (Moisture Content Targets): For optimal burning, firewood should have a moisture content of 20% or less.
Timing Estimates (Drying Times): Air drying firewood typically takes 6-12 months, depending on the wood type, climate, and stacking method. Kiln drying can reduce drying time to a few days or weeks.
Skill Levels Required: Felling large trees requires advanced chainsaw skills and experience. Bucking and splitting firewood can be learned relatively quickly with proper instruction and practice. Operating a hydraulic log splitter requires basic mechanical skills and attention to safety.

Practical Next Steps

Ready to put this information into practice? Here are some practical next steps:

Assess Your Needs: Determine the type and volume of wood processing you will be doing. This will help you decide whether a standard MS661 or a pro logging model is the right choice for you.
Research and Compare Models: Visit your local Stihl dealer and compare the features and specifications of different MS661 models. Talk to experienced loggers or firewood processors to get their recommendations.
Invest in Safety Gear: Before using a chainsaw or other wood processing equipment, invest in the necessary safety gear, including a helmet, eye protection, hearing protection, gloves, and chainsaw chaps.
Get Training: If you are new to chainsaw operation or wood processing, consider taking a training course from a qualified instructor.
Start Small and Practice: Start with small projects and gradually increase the difficulty as you gain experience. Practice your techniques and always prioritize safety.

Conclusion

Choosing the right chainsaw for logging is a critical decision that can impact your productivity, safety, and long-term success. By understanding the key differences between a standard MS661 and a pro logging model, you can make an informed choice that meets your specific needs and helps you tackle even the most challenging timber harvesting tasks. Remember to prioritize safety, invest in quality equipment, and continuously improve your skills and knowledge. With the right tools and techniques, you can transform raw wood into valuable resources and enjoy the satisfaction of working with your hands in the great outdoors. Now, get out there and make some sawdust!

Stihl MS661 Comparison Guide (5 Key Pro Logging Differences)