Stihl 021 Chainsaw Specs (5 Pro Tips For Firewood Prep)

Stihl 021 Chainsaw: A Detailed Look at the Specs

The Stihl 021 chainsaw is a lightweight, versatile tool suitable for a variety of tasks, including felling small trees, limbing, and cutting firewood. Understanding its specifications is crucial for safe and effective operation.

Engine Specifications

The heart of the Stihl 021 is its engine. It’s a single-cylinder, two-stroke engine. This design is common in chainsaws due to its high power-to-weight ratio.

Displacement: 35.2 cc (cubic centimeters). This measures the total volume displaced by the piston during one stroke. A larger displacement generally means more power.
Power Output: Approximately 1.6 kW (kilowatts) or 2.1 horsepower. This indicates the engine’s ability to perform work. For firewood, this power is adequate for cutting logs up to a moderate size.
Engine Speed: The maximum engine speed is around 12,500 RPM (revolutions per minute). This is the speed at which the engine can safely operate at full throttle.
Fuel Tank Capacity: 0.3 liters. This dictates how long you can operate the chainsaw before needing to refuel.
Fuel Mix: A 50:1 ratio of gasoline to two-stroke oil. Using the correct fuel mix is critical for engine longevity. Always use high-quality two-stroke oil.

Cutting Equipment

The cutting equipment of the Stihl 021 consists of the guide bar and the chain.

Guide Bar Length: Typically ranges from 14 to 16 inches. The guide bar length should be appropriate for the size of the wood you’re cutting. A longer bar allows you to cut larger diameter logs.
Chain Pitch: 3/8″ (0.375 inches). This refers to the distance between the drive links on the chain.
Chain Gauge: 0.050 inches. This is the thickness of the drive links.
Chain Type: Stihl recommends specific chain types for optimal performance. Consult your Stihl dealer for the best chain for your needs.

Physical Characteristics

The physical characteristics of the Stihl 021 contribute to its ease of use and maneuverability.

Weight: Approximately 4.4 kg (9.7 lbs) without fuel, bar, and chain. Its lightweight design reduces fatigue during extended use.
Dimensions: Compact dimensions make it easy to handle in tight spaces.

Key Features

The Stihl 021 includes several features that enhance its usability and safety.

Chain Brake: A safety mechanism that stops the chain instantly in case of kickback. Always ensure the chain brake is functioning correctly.
Anti-Vibration System: Reduces vibration to the operator’s hands, minimizing fatigue and improving control.
Master Control Lever: Combines choke, start, and stop functions into one lever for easy operation.

Pro Tip 1: Optimize Your Chainsaw Maintenance

Chainsaw maintenance is not just a chore; it’s an investment in the longevity, safety, and efficiency of your tool. A well-maintained chainsaw cuts faster, starts easier, and is less likely to break down in the middle of a job.

Sharpening the Chain

A sharp chain is paramount. A dull chain not only slows down your work but also increases the risk of kickback and puts unnecessary strain on the engine.

Frequency: Sharpen the chain every time you refuel, or more often if you notice the chain is cutting slowly or producing fine sawdust instead of chips.
Tools: Use a chainsaw file, a filing guide, and a depth gauge tool. The filing guide helps maintain the correct angle and depth.
Technique: File each tooth consistently, following the original angle. Use light, even strokes. Pay attention to the depth gauges, which control how much the chain bites into the wood.
Personal Story: I remember one particularly grueling firewood season where I neglected to sharpen my chain regularly. The chainsaw would bounce and vibrate, making the work exhausting and dangerous. Once I committed to sharpening the chain with each refueling, the difference was night and day. The chainsaw sliced through wood effortlessly, and my productivity soared.

Cleaning Air Filters

A clean air filter ensures the engine receives the proper amount of air for combustion. A clogged filter restricts airflow, leading to reduced power and increased fuel consumption.

Frequency: Clean the air filter after every 5-10 hours of use, or more often in dusty conditions.
Procedure: Remove the air filter cover and the filter itself. Gently tap the filter to remove loose debris. If the filter is heavily soiled, wash it with warm, soapy water, rinse thoroughly, and allow it to dry completely before reinstalling.
Insight: Some chainsaw users recommend having a spare air filter on hand. This allows you to continue working while the other filter is drying.

Checking and Replacing Spark Plugs

The spark plug ignites the fuel-air mixture in the engine. A faulty spark plug can cause starting problems or poor engine performance.

Frequency: Inspect the spark plug every 25 hours of use. Replace it annually or if it shows signs of wear or fouling.
Procedure: Remove the spark plug using a spark plug wrench. Inspect the electrode for wear, carbon buildup, or damage. Clean the electrode with a wire brush if necessary. If the spark plug is heavily fouled or damaged, replace it with a new one of the correct type.
Tip: Ensure the spark plug gap is set correctly before installing it. Refer to the Stihl 021 owner’s manual for the correct gap specification.

Lubricating the Bar and Chain

Proper lubrication is essential for reducing friction and wear on the bar and chain.

Frequency: Check the bar oil level every time you refuel.
Procedure: Fill the bar oil reservoir with high-quality bar and chain oil. Ensure the oiler is functioning correctly by observing whether oil is being dispensed onto the chain as it rotates.
Observation: A properly lubricated chain will throw off a fine mist of oil while cutting.

Inspecting and Maintaining the Guide Bar

The guide bar supports the chain and guides it through the cut. Proper maintenance ensures smooth and accurate cutting.

Frequency: Inspect the guide bar regularly for wear, damage, or burrs.
Procedure: Remove the chain and clean the guide bar with a wire brush. File down any burrs on the edges of the bar. Check the bar rails for wear. If the rails are worn unevenly, flip the bar over to distribute the wear.
Insight: Use a bar dressing tool to keep the bar rails square and smooth.

Tightening Loose Nuts and Bolts

Vibration from the chainsaw can cause nuts and bolts to loosen over time. Regularly check and tighten all fasteners to prevent parts from falling off or causing damage.

Frequency: Check all nuts and bolts before each use.
Procedure: Use a wrench or screwdriver to tighten any loose fasteners. Pay particular attention to the bar nuts, which hold the guide bar in place.

Takeaway: Regular chainsaw maintenance is vital for safety, efficiency, and longevity. Sharpen the chain, clean the air filter, check the spark plug, lubricate the bar and chain, and inspect the guide bar regularly.

Pro Tip 2: Master Safe Felling Techniques

Felling a tree is one of the most dangerous aspects of firewood preparation. Proper technique and planning are essential to avoid accidents.

Assessing the Tree and Surroundings

Before making a single cut, take the time to assess the tree and its surroundings.

Tree Lean: Determine the direction the tree is leaning. This will influence the direction of the fall.
Wind Direction: Wind can significantly affect the direction of the fall. Avoid felling trees in high winds.
Obstacles: Identify any obstacles in the path of the fall, such as power lines, buildings, or other trees.
Escape Route: Plan a clear escape route away from the tree at a 45-degree angle from the direction of the fall.
Personal Experience: I once witnessed a near-miss when a logger underestimated the lean of a tree and failed to account for a gust of wind. The tree fell in an unexpected direction, narrowly missing him. This incident reinforced the importance of careful assessment and planning.

Making the Notch Cut

The notch cut, also known as the face cut, determines the direction the tree will fall.

Angle: The notch should be cut at a 70-degree angle, with the top cut at 45 degrees and the bottom cut at 25 degrees.
Depth: The notch should be about one-fifth to one-third of the tree’s diameter.
Alignment: Ensure the notch is aligned in the direction you want the tree to fall.
Expert Advice: Use a sighting tool or an axe to align the notch accurately.

Making the Back Cut

The back cut is made on the opposite side of the tree from the notch.

Height: The back cut should be made slightly above the bottom of the notch.
Depth: Leave a hinge of wood between the back cut and the notch. The hinge controls the fall of the tree.
Technique: Cut straight into the tree, being careful not to cut through the hinge.
Safety: Never cut completely through the tree. Always leave a hinge.

Using Felling Wedges

Felling wedges are used to help direct the fall of the tree and prevent the saw from binding.

Placement: Insert the wedges into the back cut before it is completed.
Technique: Hammer the wedges in alternately to gradually lift the tree in the desired direction.
Materials: Use plastic or aluminum wedges. Never use steel wedges, as they can damage the chainsaw chain if accidentally contacted.

Retreating Safely

Once the tree begins to fall, retreat quickly along your planned escape route.

Watch Out: Be aware of falling branches and debris.
Distance: Move a safe distance away from the tree until it has completely fallen.

Takeaway: Safe felling techniques require careful assessment, precise cuts, and the use of appropriate tools. Always prioritize safety and never take shortcuts.

Pro Tip 3: Efficient Bucking and Splitting Techniques

Bucking and splitting are crucial steps in transforming felled trees into manageable firewood. Efficient techniques can save time and energy.

Bucking Techniques

Bucking is the process of cutting the felled tree into shorter, more manageable lengths.

Planning: Plan your cuts to maximize the yield of firewood and minimize waste.
Log Support: Elevate the log off the ground using other logs or a bucking stand. This prevents the chain from hitting the ground and reduces the risk of kickback.
Cutting Technique: Use a steady, controlled motion to cut through the log. Avoid forcing the saw.
Safety: Be aware of the potential for the log to pinch the saw. Use wedges to keep the cut open if necessary.
Wood Type Considerations: Different wood types require different approaches. For instance, hardwoods like oak and maple require more force and a sharper chain compared to softwoods like pine. I’ve found that adjusting my cutting speed and chain tension based on the wood type significantly improves efficiency.

Splitting Techniques

Splitting is the process of breaking the bucked logs into smaller pieces suitable for burning.

Manual Splitting: Using a splitting axe or maul.
Technique: Position the log on a solid splitting block. Stand with your feet shoulder-width apart and swing the axe or maul with a controlled motion. Aim for the center of the log.
Safety: Wear safety glasses and gloves. Be aware of your surroundings and ensure there is plenty of space around you.
Hydraulic Log Splitters: Using a hydraulic log splitter for larger or tougher logs.
Operation: Place the log on the splitter and activate the hydraulic ram to split the log.
Safety: Keep your hands clear of the splitting area. Follow the manufacturer’s instructions for safe operation.
Choosing the Right Tool: The choice between manual and hydraulic splitting depends on the size and quantity of logs you need to split. For small quantities of easily split wood, a splitting axe may be sufficient. For larger quantities or tougher wood, a hydraulic log splitter is a worthwhile investment.

Wood Stacking

Proper stacking is essential for efficient drying.

Location: Choose a sunny, well-ventilated location.
Stacking Method: Stack the wood in rows, leaving space between the rows for air circulation.
Height: Keep the stacks to a manageable height for safety and stability.
Covering: Cover the top of the stack with a tarp to protect the wood from rain and snow.
Personal Insight: I’ve experimented with different stacking methods and found that a simple criss-cross pattern at the ends of each row provides excellent stability and airflow.

Takeaway: Efficient bucking and splitting techniques can significantly reduce the time and effort required to prepare firewood. Use appropriate tools, prioritize safety, and stack the wood properly for drying.

Pro Tip 4: Master Wood Drying and Seasoning

Drying, or seasoning, firewood is essential for efficient burning and reducing smoke. Properly seasoned firewood burns hotter, cleaner, and is less likely to produce creosote buildup in your chimney.

Understanding Moisture Content

Moisture content is the key factor in determining the quality of firewood.

Freshly Cut Wood: Freshly cut wood can have a moisture content of 50% or higher.
Seasoned Wood: Seasoned firewood should have a moisture content of 20% or less.
Measuring Moisture Content: Use a moisture meter to accurately measure the moisture content of your firewood.
My Experience: I invested in a moisture meter several years ago, and it has been invaluable in determining when my firewood is ready to burn. Before, I relied on guesswork, which often resulted in smoky fires and inefficient burning.

Drying Time

The drying time for firewood depends on several factors, including the type of wood, the climate, and the stacking method.

General Guideline: As a general guideline, firewood should be seasoned for at least six months, and ideally for a year or more.
Hardwoods vs. Softwoods: Hardwoods, such as oak and maple, typically take longer to season than softwoods, such as pine and fir.
Climate Impact: In dry climates, firewood will season more quickly than in humid climates.
Accelerating Drying: To accelerate the drying process, split the wood into smaller pieces, stack it in a sunny, well-ventilated location, and cover the top of the stack with a tarp.

Identifying Seasoned Firewood

There are several visual and physical cues that indicate firewood is properly seasoned.

Color: Seasoned firewood will typically be darker in color than freshly cut wood.
Cracks: Seasoned firewood will often have cracks or splits in the ends.
Weight: Seasoned firewood will be significantly lighter than freshly cut wood.
Sound: When two pieces of seasoned firewood are struck together, they will produce a hollow sound.
Smell: Seasoned firewood will have a less pungent smell than freshly cut wood.

Storing Seasoned Firewood

Proper storage is essential for maintaining the quality of seasoned firewood.

Location: Store the firewood in a dry, well-ventilated location.
Elevation: Elevate the firewood off the ground to prevent moisture from wicking up into the wood.
Covering: Cover the top of the stack with a tarp to protect the wood from rain and snow.
Pest Control: Inspect the firewood regularly for signs of pests, such as insects or rodents. Take appropriate measures to control any infestations.
Personal Anecdote: I once stored a large pile of seasoned firewood directly on the ground, and after a heavy rain, the bottom layers became waterlogged and moldy. Since then, I’ve always made sure to elevate my firewood off the ground using pallets or wooden planks.

Takeaway: Proper drying and seasoning are essential for maximizing the efficiency and safety of your firewood. Measure the moisture content, allow ample drying time, and store the seasoned firewood in a dry, well-ventilated location.

Pro Tip 5: Understanding Wood Types for Optimal Burning

Not all firewood is created equal. Different wood types have different burning characteristics, making some better suited for firewood than others.

Hardwoods vs. Softwoods

The primary distinction between wood types is whether they are hardwoods or softwoods.

Hardwoods: Hardwoods are typically denser than softwoods and burn hotter and longer. They also produce less smoke and creosote.
Softwoods: Softwoods are less dense than hardwoods and burn more quickly. They also produce more smoke and creosote.
Examples: Common hardwoods include oak, maple, ash, and birch. Common softwoods include pine, fir, and spruce.

Burning Characteristics of Common Wood Types

Each wood type has its unique burning characteristics.

Oak: Oak is a dense, slow-burning hardwood that produces excellent heat. It is a popular choice for firewood but takes a long time to season.
Maple: Maple is another excellent hardwood that burns hot and clean. It is easier to split than oak and seasons more quickly.
Ash: Ash is a good all-around firewood that burns hot and produces little smoke. It is relatively easy to split and seasons quickly.
Birch: Birch is a medium-density hardwood that burns hot and produces a pleasant aroma. However, it can be difficult to split and is prone to rot if not seasoned properly.
Pine: Pine is a softwood that burns quickly and produces a lot of smoke. It is not ideal for firewood but can be used for kindling or starting fires.
Fir: Fir is another softwood that burns quickly and produces a moderate amount of smoke. It is not ideal for firewood but can be used for shoulder season burning when less heat is needed.

BTU (British Thermal Unit) Ratings

BTU is a measure of the heat content of firewood.

Higher BTU: Wood types with higher BTU ratings produce more heat per unit volume.
BTU Variation: BTU ratings can vary depending on the moisture content of the wood.
Examples: Oak typically has a BTU rating of around 28 million per cord, while pine has a BTU rating of around 16 million per cord.

Selecting the Right Wood Type

The best wood type for firewood depends on your specific needs and preferences.

Heating Needs: If you need a lot of heat, choose a dense hardwood with a high BTU rating.
Ease of Use: If you want firewood that is easy to split and seasons quickly, choose a less dense hardwood or a softwood.
Availability: Consider the availability and cost of different wood types in your area.
Personal Preference: Some people prefer the aroma or burning characteristics of certain wood types.
Real-World Scenario: I live in an area where oak and maple are readily available, so I primarily use those wood types for firewood. However, I also keep a small supply of pine for kindling and starting fires.

Avoiding Problematic Wood

Some wood types should be avoided for firewood.

Treated Wood: Treated wood contains chemicals that can release harmful fumes when burned.
Painted Wood: Painted wood can also release harmful fumes when burned.
Diseased Wood: Diseased wood may not burn properly and can spread disease to other trees.
Expert Tip: Always source your firewood from reputable suppliers and avoid burning wood of unknown origin.

Takeaway: Understanding the burning characteristics of different wood types can help you select the best firewood for your needs. Choose dense hardwoods for maximum heat, avoid problematic wood types, and consider the availability and cost of different options in your area.

By mastering these five pro tips and understanding the Stihl 021 chainsaw specs, you can transform your firewood preparation process into a safe, efficient, and rewarding experience. Remember, safety should always be your top priority, and proper maintenance is key to prolonging the life of your chainsaw. With the right knowledge and techniques, you can enjoy the warmth and comfort of a wood-burning fire all winter long.