Stihl MS 660 Specs: Pro Chainsaw Guide (7 Key Logging Insights)

Introduction: The Logging Lifestyle and the Right Chainsaw

For many, logging isn’t just a job; it’s a way of life. I’ve spent years in the woods, felling trees, bucking logs, and preparing firewood. The demanding nature of this work requires tools that can withstand the rigors of daily use. The chainsaw is arguably the most crucial tool in a logger’s kit. Choosing the right chainsaw can significantly impact productivity, safety, and overall job satisfaction. That’s why selecting a powerful and reliable chainsaw is crucial. The Stihl MS 660 has earned its reputation as a workhorse in the logging industry, and for good reason. This guide explores why.

1. Stihl MS 660: An Overview of a Logging Legend

The Stihl MS 660 is a professional-grade chainsaw designed for demanding tasks like felling large trees and processing heavy timber. It’s known for its powerful engine, robust construction, and reliability in harsh conditions. This chainsaw isn’t for the occasional user; it’s built for professionals who depend on their tools day in and day out.

My first encounter with an MS 660 was during a particularly challenging logging project in the Pacific Northwest. We were dealing with massive Douglas firs, and our smaller saws were struggling. The MS 660 effortlessly sliced through the thick trunks, increasing our efficiency and reducing fatigue. From that moment on, I understood the value of having a truly powerful chainsaw.

2. Key Specifications: Power and Performance Under the Hood

Understanding the specifications of the Stihl MS 660 is essential for appreciating its capabilities. Here’s a breakdown of the key specs:

• Engine Displacement: 91.6 cc (5.6 cu. in.)
• Power Output: 5.2 kW (7.1 bhp)
• Weight (Powerhead Only): 7.3 kg (16.1 lbs)
• Fuel Tank Capacity: 0.825 L (27.9 oz)
• Oil Tank Capacity: 0.360 L (12.2 oz)
• Recommended Bar Lengths: 20″ to 36″ (50 cm to 90 cm)
• Sound Pressure Level: 103 dB(A)
• Sound Power Level: 115 dB(A)
• Vibration Level (Front/Rear): 6.9 / 5.5 m/s²

These specs paint a clear picture: the MS 660 is a powerhouse. The large engine displacement provides ample torque for cutting through dense wood, while the relatively lightweight design (for its power) minimizes fatigue. The fuel and oil tank capacities allow for extended run times between refills, crucial when working in remote locations.

Metric Conversion Table:

Takeaway: The MS 660’s specifications highlight its robust engine, manageable weight, and ample fuel capacity, making it a top choice for demanding logging tasks.

3. The Engine: Heart of the Beast

The MS 660’s 91.6 cc engine is the heart of its power. This two-stroke engine is designed for high performance and durability. Here are some critical aspects of the engine:

• Cylinder Design: The engine features a single-cylinder design with a chrome-plated cylinder bore for increased wear resistance and longevity.
• Fuel System: It uses a carburetor to mix fuel and air efficiently, ensuring optimal combustion and power output.
• Ignition System: The electronic ignition system provides reliable starting and consistent performance, even in cold weather.
• Air Filtration: The advanced air filtration system protects the engine from dust and debris, extending its lifespan and maintaining peak performance.
• Decompression Valve: A decompression valve reduces the pulling force required to start the engine, making it easier to start, especially in cold conditions.

My Insight: I’ve found that regular maintenance, especially cleaning the air filter and using high-quality fuel and oil, is crucial for keeping the MS 660’s engine running smoothly. Neglecting these simple tasks can lead to reduced performance and costly repairs.

Takeaway: The MS 660’s engine is engineered for power, durability, and reliability, making it a dependable workhorse for demanding logging applications.

4. Chain and Bar Selection: Matching the Tool to the Task

Choosing the right chain and bar for your Stihl MS 660 is crucial for maximizing performance and safety. The recommended bar lengths for the MS 660 range from 20″ to 36″, but the optimal choice depends on the size of the trees you’ll be felling.

• Bar Length: A longer bar allows you to fell larger trees without excessive bending, but it also increases the weight and can reduce maneuverability. I typically use a 28″ bar for most logging tasks, as it provides a good balance of reach and control.
• Chain Type: Different chain types are designed for different cutting conditions. Full-chisel chains are the fastest-cutting but require more sharpening and are more prone to kickback. Semi-chisel chains are more durable and forgiving, making them a good choice for dirty or frozen wood.
• Chain Pitch and Gauge: The chain pitch and gauge must match the sprocket on the chainsaw. The MS 660 typically uses a .404″ pitch chain with a .063″ gauge.

Chain Sharpening: Maintaining a sharp chain is essential for efficient cutting and safety. I use a chainsaw file and a depth gauge to sharpen my chains regularly. A dull chain not only slows down cutting but also increases the risk of kickback.

Data Point: Studies have shown that a properly sharpened chain can increase cutting speed by up to 30% and reduce fuel consumption by 10%.

Takeaway: Selecting the appropriate bar length and chain type for the MS 660 is critical for optimizing performance and safety. Regular chain sharpening is essential for maintaining efficiency and reducing the risk of accidents.

5. Ergonomics and Handling: Minimizing Fatigue and Maximizing Control

Despite its power, the Stihl MS 660 is designed with ergonomics in mind. Features like the anti-vibration system and comfortable handles help reduce fatigue and improve control.

• Anti-Vibration System: The MS 660’s anti-vibration system isolates the engine from the handles, reducing the amount of vibration transmitted to the operator. This helps minimize fatigue and allows for longer periods of operation.
• Handle Design: The ergonomic handle design provides a comfortable and secure grip, even when wearing gloves. The handles are also spaced to provide good balance and control.
• Weight Distribution: The MS 660’s weight is well-distributed, making it easier to maneuver and control, even when felling large trees.

Personal Experience: I’ve used chainsaws without adequate vibration dampening, and the difference is significant. After a few hours of use, my hands and arms would be numb and fatigued. The MS 660’s anti-vibration system makes a noticeable difference, allowing me to work longer with less discomfort.

Takeaway: The MS 660’s ergonomic design and anti-vibration system contribute to reduced fatigue and improved control, making it a more comfortable and safer chainsaw to operate.

6. Safety Features: Protecting the Operator

Safety is paramount when operating a chainsaw, and the Stihl MS 660 incorporates several features to protect the operator.

• Chain Brake: The chain brake is a crucial safety feature that stops the chain immediately in the event of kickback. It can be activated manually or automatically by inertia.
• Throttle Lockout: The throttle lockout prevents accidental throttle engagement, reducing the risk of unintended chain movement.
• Chain Catcher: The chain catcher prevents the chain from flying back towards the operator if it breaks or comes off the bar.
• Hand Guard: The hand guard protects the operator’s hand from debris and helps prevent contact with the chain.

Safety Gear: Always wear appropriate safety gear when operating a chainsaw, including:

• Helmet: A helmet with a face shield protects your head and face from falling debris and kickback.
• Eye Protection: Safety glasses or goggles provide additional eye protection.
• Hearing Protection: Earplugs or earmuffs protect your hearing from the loud noise of the chainsaw.
• Gloves: Heavy-duty gloves provide a secure grip and protect your hands from cuts and abrasions.
• Chainsaw Chaps: Chainsaw chaps protect your legs from accidental contact with the chain.
• Steel-Toed Boots: Steel-toed boots protect your feet from falling logs and other hazards.

Statistics: According to the Consumer Product Safety Commission, approximately 36,000 people are treated in hospital emergency rooms each year for chainsaw-related injuries. Wearing appropriate safety gear can significantly reduce the risk of injury.

Takeaway: The MS 660 incorporates multiple safety features to protect the operator. Always wear appropriate safety gear and follow safe operating procedures to minimize the risk of accidents.

7. Maintenance and Longevity: Keeping Your Saw in Top Condition

Proper maintenance is essential for ensuring the longevity and performance of your Stihl MS 660. Regular maintenance tasks include:

• Cleaning the Air Filter: Clean the air filter regularly to prevent dust and debris from entering the engine. I recommend cleaning it after every 10 hours of use.
• Checking and Cleaning the Spark Plug: Inspect the spark plug regularly and clean or replace it as needed. A fouled spark plug can cause starting problems and reduced performance.
• Sharpening the Chain: Keep the chain sharp for efficient cutting and safety. Sharpen the chain every few hours of use or whenever it becomes dull.
• Checking and Adjusting the Carburetor: The carburetor may need to be adjusted periodically to ensure optimal fuel-air mixture. Consult the owner’s manual for instructions.
• Lubricating the Bar and Chain: Use a high-quality bar and chain oil to keep the bar and chain properly lubricated. This reduces friction and wear, extending the life of the bar and chain.
• Inspecting the Fuel and Oil Lines: Check the fuel and oil lines for cracks or leaks and replace them as needed. Leaky lines can cause fuel or oil starvation, leading to engine damage.
• Storing the Chainsaw Properly: When not in use, store the chainsaw in a dry, safe place. Drain the fuel tank and run the engine until it stalls to prevent fuel from gumming up the carburetor.

Maintenance Schedule:

Cost of Maintenance: The cost of maintaining a Stihl MS 660 can vary depending on the frequency of use and the type of maintenance performed. However, regular maintenance can prevent costly repairs and extend the life of the chainsaw.

Takeaway: Regular maintenance is crucial for ensuring the longevity and performance of your Stihl MS 660. Follow the manufacturer’s recommendations for maintenance and use high-quality fuel and oil to keep your chainsaw running smoothly.

Bonus: 7 Key Logging Insights for MS 660 Users

Beyond the specs and maintenance, here are seven key insights I’ve learned over years of using the MS 660 in the field:

1. Understanding Wood Density: Different wood species have different densities, affecting cutting speed and chain wear. Softer woods like pine cut faster but dull the chain quicker than hardwoods like oak. Adjust your cutting technique and chain sharpening frequency accordingly. I use a moisture meter to check wood density. It helps me anticipate how the wood will behave and adjust my cutting strategy accordingly.
2. Felling Techniques: Mastering proper felling techniques is crucial for safety and efficiency. Always assess the tree’s lean, wind direction, and potential hazards before making any cuts. Use a combination of undercut and back cut to control the direction of the fall. I always clear escape routes before making the first cut, ensuring a safe path away from the falling tree.
3. Bucking Strategies: Efficient bucking involves cutting felled trees into manageable logs. Plan your cuts carefully to minimize waste and maximize the value of the timber. Use a measuring tape and log scale to determine the optimal log lengths. I’ve learned to identify defects in the wood and adjust my cuts to avoid them, improving the overall quality of the logs.
4. Limbing Techniques: Limbing, or removing branches from a felled tree, can be dangerous. Always work from the base of the tree towards the top, keeping the chainsaw between you and the trunk. Use a sweeping motion to remove the branches, being careful to avoid kickback. I always maintain a firm grip on the chainsaw and keep my feet firmly planted to prevent slips and falls.
5. Fuel and Oil Management: Use high-quality fuel and oil specifically designed for two-stroke engines. Mix the fuel and oil according to the manufacturer’s recommendations. Store fuel in a sealed container in a cool, dry place. I always carry extra fuel and oil with me when working in remote locations, ensuring I don’t run out of supplies.
6. Chain Sharpening in the Field: Learn to sharpen your chain in the field using a chainsaw file and a depth gauge. A sharp chain is essential for efficient cutting and safety. Practice sharpening until you can consistently achieve a sharp, even edge. I carry a small sharpening kit with me at all times, allowing me to touch up the chain whenever it becomes dull.
7. Listening to Your Saw: Pay attention to the sound and feel of your chainsaw. Unusual noises or vibrations can indicate a problem. Address any issues promptly to prevent further damage. I’ve learned to recognize the subtle changes in the sound of my MS 660, allowing me to identify potential problems before they become major issues.

Takeaway: Mastering these key logging insights can significantly improve your efficiency, safety, and overall success when using the Stihl MS 660.

Conclusion: The Stihl MS 660 – A Logging Investment

The Stihl MS 660 is more than just a chainsaw; it’s an investment in your productivity and safety. Its powerful engine, robust construction, and ergonomic design make it a top choice for professional loggers. By understanding its specifications, mastering proper operating techniques, and performing regular maintenance, you can ensure that your MS 660 provides years of reliable service.

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