660 Chainsaw Insights (Pro Tips For Heavy-Duty Woodcutting)

Here’s an opportunity: Mastering your 660 chainsaw isn’t just about making cuts; it’s about unlocking efficiency, safety, and a deeper connection with the raw materials of the earth. Whether you’re felling trees, bucking logs for firewood, or tackling storm cleanup, the Stihl MS 660 (or its equivalents from other manufacturers) is a powerhouse. But power without control is just potential wasted. In this guide, I’ll share pro tips and insights gleaned from years of experience to help you wield this beast like a true woodcutting professional.

660 Chainsaw Insights (Pro Tips for Heavy-Duty Woodcutting)

The Stihl MS 660, and similar heavy-duty chainsaws, are designed for demanding tasks. They offer significant advantages in terms of power and cutting capacity, but they also require a high level of skill and understanding to operate safely and effectively. This guide aims to bridge the gap between owning a powerful chainsaw and truly mastering it.

Understanding Your 660 Chainsaw

Before diving into advanced techniques, let’s cover the fundamentals. It’s crucial to understand the machine’s components and how they work together.

Engine: Typically a 90cc+ two-stroke engine. These engines require a precise mix of gasoline and two-stroke oil. Always refer to your owner’s manual for the correct ratio. I’ve seen countless engine failures caused by incorrect fuel mixtures. Don’t skip this step!
Bar and Chain: The bar guides the chain, and the chain does the actual cutting. Bar length should be chosen based on the diameter of the wood you’ll be cutting. A longer bar can handle larger trees, but it also requires more power and increases the risk of kickback. Chain types vary depending on the application. Full chisel chains are aggressive but require more sharpening, while semi-chisel chains are more forgiving and stay sharper longer.
Clutch: Engages the chain when the engine reaches a certain RPM. A slipping clutch can indicate wear and tear and should be addressed promptly.
Brake: A critical safety feature that stops the chain instantly in case of kickback or other emergencies. Always test the brake before each use.
Anti-Vibration System: Reduces fatigue and improves control by isolating the engine from the handles.
Oiling System: Automatically lubricates the chain. Proper oiling is essential for chain life and cutting efficiency. Check the oil level frequently.
Carburetor: Mixes air and fuel. Adjusting the carburetor can optimize performance, especially at different altitudes. I once spent a frustrating day trying to cut hardwood at high altitude before realizing the carburetor needed adjustment. A simple tweak made all the difference.

Key Terms:

Green Wood: Freshly cut wood with high moisture content. It’s heavier and more difficult to split than seasoned wood.
Seasoned Wood: Wood that has been dried to reduce its moisture content. It’s lighter, easier to split, and burns more efficiently. Target moisture content for firewood is typically below 20%.
Kickback: A dangerous situation where the chainsaw bar is thrown back towards the operator. It’s often caused by the tip of the bar contacting an object.
Bucking: Cutting a felled tree into shorter, manageable lengths.
Felling: Cutting down a standing tree.

Chainsaw Maintenance: The Key to Longevity

Regular maintenance is paramount for maximizing the lifespan and performance of your 660 chainsaw.

Chain Sharpening: A sharp chain is safer and more efficient. Learn to sharpen your chain with a file and guide. Maintain the correct angles and depth gauge settings. Alternatively, use a chain grinder for faster and more precise sharpening. I prefer hand filing for touch-ups in the field, but I use a grinder for major sharpening sessions.
- File Size: Typically a 7/32″ round file for .325″ pitch chains and a 13/64″ round file for 3/8″ pitch chains.
- Sharpening Angle: Refer to your chain manufacturer’s specifications.
Air Filter Cleaning: A dirty air filter restricts airflow and reduces engine performance. Clean the air filter regularly with compressed air or soap and water. Replace it when necessary.
Spark Plug Inspection: Inspect the spark plug for signs of wear or fouling. Clean or replace it as needed. A healthy spark plug ensures reliable starting and smooth engine operation.
Bar Maintenance: Clean the bar groove regularly to remove sawdust and debris. Check the bar rails for wear and file them down if necessary. Flip the bar periodically to ensure even wear.
Chain Oiler Adjustment: Ensure the chain oiler is working properly. Adjust the oil flow rate as needed based on the type of wood you’re cutting and the bar length. I increase the oil flow when cutting hardwoods to prevent the chain from overheating.
Fuel System Maintenance: Use fresh, high-quality gasoline and two-stroke oil. Drain the fuel tank before storing the chainsaw for extended periods. Clean the fuel filter regularly.
Overall Cleaning: Regularly clean the entire chainsaw to remove sawdust, dirt, and debris. This will help prevent corrosion and ensure smooth operation.
Professional Inspection: Schedule annual professional inspections and tune-ups to catch potential problems early.

Essential Safety Gear

Operating a chainsaw is inherently dangerous. Always wear appropriate safety gear to minimize the risk of injury.

Helmet: Protects your head from falling branches and kickback.
Eye Protection: Safety glasses or a face shield protect your eyes from flying debris.
Hearing Protection: Earplugs or earmuffs protect your hearing from the loud noise of the chainsaw.
Gloves: Provide a secure grip and protect your hands from cuts and abrasions.
Chainsaw Chaps: Protect your legs from accidental contact with the chain. I’ve seen chaps save countless legs. They’re an absolute must-have.
Steel-Toed Boots: Protect your feet from falling logs and chainsaw accidents.
First-Aid Kit: Keep a well-stocked first-aid kit readily available in case of injury.

Felling Techniques: Mastering the Art of Tree Removal

Felling a tree is a complex and potentially dangerous task. It requires careful planning, precise cuts, and a thorough understanding of tree behavior.

Risk Assessment: Before felling any tree, conduct a thorough risk assessment. Identify potential hazards such as power lines, buildings, roads, and other trees. Assess the tree’s lean, wind direction, and any signs of decay or weakness.
Planning the Fall: Determine the desired direction of fall. Consider the tree’s natural lean, wind direction, and obstacles in the area. Clear the area around the tree of any debris or obstructions. Create a clear escape path at a 45-degree angle away from the anticipated direction of fall.
The Notch Cut (Undercut): The notch cut determines the direction of fall. It consists of two cuts:
- The Horizontal Cut: Cut horizontally into the tree trunk to a depth of about 1/3 of the tree’s diameter.
- The Angled Cut: Cut downwards at a 45-degree angle to meet the horizontal cut. Remove the wedge of wood.
- Notch Size: The wider the notch, the more control you have over the direction of fall.
The Back Cut: The back cut is made on the opposite side of the tree from the notch. It should be slightly higher than the horizontal cut of the notch.
- Hinge Wood: Leave a hinge of wood (approximately 10% of the tree’s diameter) between the back cut and the notch. The hinge controls the fall of the tree.
- Wedges: Insert wedges into the back cut to prevent the tree from pinching the bar and to help direct the fall. I always carry multiple wedges of different sizes. They can be lifesavers, especially with larger trees.
The Final Push (If Necessary): If the tree doesn’t start to fall on its own, use a felling lever or wedges to give it a final push.
Escape: Once the tree starts to fall, retreat quickly along your escape path. Watch out for falling branches.
Case Study: I once had to fell a large oak tree leaning heavily towards a neighbor’s house. The risk was high. I used a combination of precise notching, strategically placed wedges, and a come-along attached to a nearby tree to pull the oak in the opposite direction. It was a slow and deliberate process, but it worked perfectly.

Important Considerations:

Tree Lean: Trees with a significant lean require extra caution. Use wedges and pulling techniques to control the fall.
Wind: Avoid felling trees in high winds. The wind can make it difficult to control the direction of fall.
Tree Size: Larger trees require more planning and specialized techniques. Consider hiring a professional arborist for very large or hazardous trees.
Bore Cutting: Can be used to fell trees with significant lean. This involves boring a hole through the tree and then making the back cut. However, this technique requires advanced skills and knowledge.

Bucking Logs: Converting Trees into Usable Lumber

Bucking is the process of cutting felled trees into shorter lengths for firewood, lumber, or other purposes.

Safety First: Ensure the log is stable and won’t roll or shift during cutting. Use wedges or supports to prevent the log from pinching the bar.
Planning the Cuts: Determine the desired lengths for your firewood or lumber. Mark the log accordingly.
Cutting Techniques:
- Overbucking: Cutting from the top down. Use this technique when the log is supported from below.
- Underbucking: Cutting from the bottom up. Use this technique when the log is supported from above.
- Combined Cuts: Use a combination of overbucking and underbucking to prevent the log from pinching the bar.
Log Supports: Use log supports or sawhorses to raise the log off the ground. This will make cutting easier and safer.
Debarking: Removing the bark from logs can speed up the drying process and reduce the risk of insect infestation. Use a drawknife or debarking spud.
Limbing: Removing branches from a felled tree before bucking is called limbing. This makes the bucking process easier and safer. I prefer to limb the tree as soon as possible after felling, while the branches are still flexible.

Firewood Preparation: From Log to Hearth

Preparing firewood is a rewarding but labor-intensive task. The goal is to produce seasoned firewood that burns efficiently and cleanly.

Splitting: Splitting logs into smaller pieces increases the surface area and speeds up the drying process.
- Axes: Traditional splitting axes are effective for smaller logs. Choose an axe with a weight and handle length that suits your strength and height.
- Mauls: Heavier than axes, mauls are better for splitting larger, tougher logs.
- Hydraulic Log Splitters: Hydraulic log splitters are the most efficient way to split large quantities of firewood. They can handle logs of varying sizes and hardness. Investing in a hydraulic splitter was a game-changer for my firewood operation. It significantly reduced the physical strain and increased my productivity.
  - Tonnage: Choose a log splitter with sufficient tonnage for the type of wood you’ll be splitting. A 20-ton splitter is generally adequate for most firewood applications.
  - Cycle Time: The cycle time is the time it takes for the splitter to complete one splitting cycle. A faster cycle time means more firewood processed per hour.
- Manual Wedges: Effective, but physically demanding.
Stacking: Stack firewood in a way that promotes airflow. This will help it dry more quickly.
- Rick: A single row of stacked firewood.
- Cord: A stack of firewood measuring 4 feet high, 4 feet wide, and 8 feet long (128 cubic feet).
- Stacking Methods:
  - Criss-Cross Stacking: Creates a stable and well-ventilated stack.
  - Circular Stacking: An aesthetically pleasing option, but may not provide as much airflow.
Drying: Firewood needs to be dried (seasoned) before it can be burned efficiently.
- Drying Time: Drying time varies depending on the type of wood, the climate, and the stacking method. Generally, firewood needs to dry for at least six months, and preferably a year or more.
- Moisture Content: Use a moisture meter to check the moisture content of the firewood. Aim for a moisture content below 20%.
- Wood Type: Hardwoods like oak, maple, and ash are denser and produce more heat than softwoods like pine and fir. However, softwoods dry more quickly.
Storage: Store seasoned firewood in a dry, well-ventilated location. Cover the top of the stack to protect it from rain and snow.
Case Study: I experimented with different firewood stacking methods to optimize drying time. I found that criss-cross stacking in a sunny, windy location resulted in the fastest drying times. I also used a moisture meter to track the drying process and ensure the firewood was properly seasoned before burning.

Data and Insights:

Average Drying Time for Oak: 12-18 months
Average Drying Time for Pine: 6-12 months
Ideal Firewood Moisture Content: Below 20%
Heat Value of Different Wood Types: Oak (28 million BTU per cord), Maple (24 million BTU per cord), Pine (18 million BTU per cord)

Advanced Techniques and Troubleshooting

Once you’ve mastered the basics, you can explore more advanced techniques and troubleshooting tips.

Bore Cutting (Felling): Used for felling trees with a significant lean or for removing large branches. Requires advanced skills and knowledge.
Reactive Forces: Understanding reactive forces (pinch, kickback) is crucial for safe chainsaw operation.
Chain Binding: Learn how to free a bound chain safely.
Engine Troubleshooting: Diagnose and repair common engine problems such as starting difficulties, poor performance, and overheating.
Carburetor Tuning: Fine-tune the carburetor for optimal performance at different altitudes and temperatures.
Sharpening Specialty Chains: Learn to sharpen skip chains and other specialty chains.

Strategic Advantages of Efficient Wood Processing

Efficient wood processing offers several strategic advantages:

Cost Savings: Producing your own firewood can save you money on heating bills.
Self-Sufficiency: Provides a reliable source of fuel for heating and cooking.
Environmental Benefits: Using firewood from sustainably managed forests can be a carbon-neutral heating source.
Exercise: Wood processing is a great form of exercise.
Skill Development: Mastering wood processing skills can be empowering and rewarding.
Business Opportunity: Firewood sales can provide a supplemental income.

Costs, Material Specs, Timing, and Skill Levels

Chainsaw (Stihl MS 660 or Equivalent): $1200 – $1500 (Skill Level: Intermediate to Advanced)
Safety Gear: $200 – $500 (Skill Level: All)
Axes and Mauls: $50 – $200 each (Skill Level: Beginner to Intermediate)
Hydraulic Log Splitter: $1000 – $3000 (Skill Level: Beginner)
Moisture Meter: $30 – $100 (Skill Level: All)
Material Specs (Firewood): Moisture content below 20%, length appropriate for your stove or fireplace.
Timing (Firewood Drying): 6-18 months depending on wood type and climate.

Challenges Faced by Global DIYers and Small-Scale Logging Businesses

Access to Equipment: The cost of chainsaws and other wood processing equipment can be a barrier for some DIYers and small businesses.
Training and Education: Lack of access to proper training and education can lead to unsafe practices.
Regulations: Logging and firewood sales are often subject to regulations. It’s important to understand and comply with these regulations.
Market Competition: The firewood market can be competitive.
Sustainable Practices: Ensuring sustainable logging and firewood harvesting practices is essential for long-term viability.
Climate Change: Changing weather patterns can affect firewood drying times and availability.

Next Steps

Ready to put these pro tips into action? Here are some practical next steps:

Safety First: Invest in the necessary safety gear and familiarize yourself with safe chainsaw operating procedures.
Start Small: Begin with smaller projects to build your skills and confidence.
Practice Regularly: The more you practice, the better you’ll become.
Seek Guidance: Don’t be afraid to ask for help from experienced woodcutters or arborists.
Continuous Learning: Stay up-to-date on the latest techniques and safety standards.

By following these guidelines and continuously honing your skills, you can unlock the full potential of your 660 chainsaw and become a true woodcutting professional. Remember, safety is always the top priority. Happy cutting!

660 Chainsaw Insights (Pro Tips for Heavy-Duty Woodcutting)