021 Stihl Chainsaw Chain Issues (5 Expert Fixes for Pros)
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021 Stihl Chainsaw Chain Issues (5 Expert Fixes for Pros)
For many of us, the Stihl 021 chainsaw represents the sweet spot between affordability and reliability. It’s the workhorse that gets the job done without breaking the bank. I’ve personally owned and maintained a few 021s over the years, and while they’re generally dependable, they’re not immune to chain-related issues. Let’s face it, a dull or improperly tensioned chain can turn a simple firewood-cutting task into an all-day wrestling match. That’s why I’ve put together this guide, drawing from my own experiences and years of tinkering with chainsaws, to help you troubleshoot and fix the most common chain problems you might encounter with your Stihl 021. We’ll keep it practical, focusing on solutions you can implement in your own workshop, regardless of your experience level.
Why Focus on Affordability?
Before we dive into the nitty-gritty, let’s address the elephant in the room: why focus on affordability? Well, for many hobbyists, small-scale loggers, and firewood producers, budget is a real constraint. We’re not all running high-end forestry operations with unlimited resources. I remember when I first started cutting firewood to heat my home. I was scraping by, and every penny counted. The Stihl 021 was a godsend because it was a chainsaw I could afford, and with a little TLC, it could handle the workload.
This guide is built on the same principle: providing practical, cost-effective solutions to keep your Stihl 021 chainsaw chain running smoothly, without requiring you to invest in expensive tools or professional services. We’ll cover everything from sharpening techniques to tensioning adjustments, all with an eye towards maximizing performance and extending the life of your chain, and ultimately, your chainsaw.
Troubleshooting Common Stihl 021 Chainsaw Chain Issues
Let’s break down the most common chain problems I’ve seen with the Stihl 021 and the expert fixes I’ve learned to apply.
1. The Dull Chain Dilemma
A dull chain is the bane of any chainsaw user’s existence. It makes cutting slow, difficult, and even dangerous. You’ll know your chain is dull when it produces fine sawdust instead of chips, requires excessive force to cut, and causes the saw to vibrate excessively.
The Root Cause
- Hitting dirt or debris: This is the most common culprit. Even a brief encounter with the ground can dull the cutting edges. I once spent an entire afternoon cutting firewood only to discover I’d been unknowingly dragging the chain through a patch of dirt hidden under some leaves. A costly mistake!
- Cutting hardwoods: Hardwoods like oak and maple are much tougher on chains than softwoods like pine.
- Infrequent sharpening: Even with careful use, chains will naturally dull over time.
Expert Fix: Sharpening the Chain
Sharpening your chain is the most important maintenance task. You have two main options: manual sharpening with a file or using a chainsaw sharpener.
- Manual Sharpening: This is the most common and cost-effective method.
- Tools Required:
- Chainsaw file (typically 5/32″ for Stihl 021, but always check your chain specifications). The file size is crucial for maintaining the correct cutting angle.
- File guide (optional, but highly recommended for beginners).
- Depth gauge tool and flat file.
- Gloves.
- Steps:
- Secure the Chainsaw: Place the chainsaw in a vise or clamp it securely to a workbench.
- Identify the Correct Angle: The correct sharpening angle is usually stamped on the chain itself. For Stihl 021 chains, it’s typically around 30 degrees.
- File Each Cutter: Using the file guide (if you have one), hold the file at the correct angle and file each cutter from the inside out. Apply consistent pressure and stroke the file several times until the cutter is sharp.
- Maintain Consistency: It’s crucial to file each cutter the same amount to ensure even cutting. I like to count the number of strokes for each cutter to maintain consistency.
- Check and Adjust Depth Gauges: The depth gauges (also known as rakers) control how much the cutter takes with each pass. Use the depth gauge tool and flat file to lower the depth gauges if they are too high. The recommended depth gauge setting for the Stihl 021 is typically 0.025″ (0.635mm). Overly aggressive depth gauges can cause the chain to grab and kick back.
- Test the Chain: After sharpening, test the chain on a piece of wood. It should produce clean, even chips.
- Data Point: A properly sharpened chain should produce chips that are approximately 1/8″ to 1/4″ in size.
- Tools Required:
- Chainsaw Sharpener: These electric or manual sharpeners offer a faster and more precise sharpening process.
- Types: Bench-mounted electric sharpeners, handheld electric sharpeners, and manual crank sharpeners.
- Pros: Faster, more precise, and easier to use for beginners.
- Cons: More expensive than manual sharpening.
- Technical Requirement: Ensure the sharpener is compatible with your chain’s pitch and gauge.
- Personal Experience: I’ve used both manual and electric sharpeners. While electric sharpeners are faster, I still prefer manual sharpening for fine-tuning and maintaining a precise cutting edge.
- Unique Insight: A trick I learned from an old logger is to use a marker to color the cutting edges before sharpening. This helps you see exactly where you’re filing and ensures you’re removing material evenly.
2. The Sagging Chain Saga: Tension Troubles
Proper chain tension is crucial for safe and efficient operation. A chain that’s too loose can derail, causing damage to the saw and potentially injuring the operator. A chain that’s too tight can overheat, wear out prematurely, and even damage the bar and sprocket.
The Root Cause
- Chain Stretch: Chains naturally stretch over time as they wear.
- Temperature Fluctuations: The chain expands when it gets hot and contracts when it cools down.
- Improper Initial Tensioning: If the chain wasn’t properly tensioned to begin with, it will likely loosen quickly. I made this mistake once when I was rushing to finish a job before dark. The chain derailed within minutes, and I had to spend valuable time reassembling it.
Expert Fix: Adjusting Chain Tension
- Tools Required:
- Scrench (the combination wrench and screwdriver that came with your Stihl 021).
- Gloves.
- Steps:
- Loosen the Bar Nuts: Use the scrench to loosen the bar nuts on the side of the chainsaw. Do not remove them completely.
- Locate the Tensioning Screw: The tensioning screw is usually located on the side of the chainsaw, near the bar.
- Adjust the Tension: Use the scrench to turn the tensioning screw. Turning it clockwise tightens the chain, while turning it counterclockwise loosens it.
- Check the Tension: The correct tension is when you can pull the chain away from the bar about 1/8″ (3mm) in the middle of the bar. When you release the chain, it should snap back against the bar.
- Tighten the Bar Nuts: Once the chain is properly tensioned, tighten the bar nuts securely.
- Important Note: Always check the chain tension after the first few cuts, as it will likely loosen slightly as the chain heats up.
- Technical Requirement: The chain should be tensioned when the saw is cool. Tensioning a hot chain can lead to over-tightening when it cools down.
- Unique Insight: A simple trick to remember the correct tension is to imagine the chain as a rubber band. It should be snug but not stretched too tight.
3. The Oiling Obstacle: Lubrication Lack
Proper lubrication is essential for extending the life of your chain and bar. Without sufficient oil, the chain will overheat, wear out quickly, and can even seize up.
The Root Cause
- Empty Oil Reservoir: The most obvious reason! Always check the oil level before starting your chainsaw.
- Clogged Oiler: Sawdust and debris can clog the oiler, preventing oil from reaching the chain.
- Faulty Oil Pump: The oil pump may be damaged or malfunctioning.
- Incorrect Oil Type: Using the wrong type of oil can also cause lubrication problems.
Expert Fixes: Ensuring Proper Lubrication
- Check the Oil Reservoir: Regularly check the oil level and refill as needed. I recommend using a high-quality bar and chain oil specifically designed for chainsaws.
- Clean the Oiler:
- Locate the Oiler Hole: The oiler hole is usually located on the bar, near the sprocket.
- Use a Wire or Small Tool: Use a small wire or tool to clear any debris from the oiler hole.
- Compressed Air: Use compressed air to blow out any remaining debris.
- Frequency: I recommend cleaning the oiler every time you sharpen the chain.
- Check the Oil Pump:
- Location: The oil pump is usually located near the engine.
- Visual Inspection: Inspect the oil pump for any signs of damage or wear.
- Testing: With the chainsaw running, check if oil is being dispensed from the oiler hole. If not, the oil pump may need to be replaced.
- Technical Requirement: If replacing the oil pump, ensure you use the correct replacement part for your Stihl 021.
- Use the Correct Oil:
- Recommended Oil: Stihl bar and chain oil is a good choice, but any high-quality bar and chain oil will work.
- Viscosity: The oil should be viscous enough to cling to the chain but not so thick that it clogs the oiler.
- Environmental Considerations: Consider using a biodegradable bar and chain oil to minimize environmental impact.
- Unique Insight: A simple test to check if the chain is being properly lubricated is to hold the chainsaw over a piece of cardboard while running it at full throttle. You should see a fine mist of oil being sprayed onto the cardboard.
4. The Derailment Drama: Chain Coming Off
A chain that repeatedly comes off the bar is not only frustrating but also dangerous.
The Root Cause
- Loose Chain Tension: As mentioned earlier, a chain that’s too loose is more likely to derail.
- Worn Sprocket: A worn sprocket can cause the chain to skip and derail.
- Damaged Bar: A bent or damaged bar can also cause the chain to derail.
- Incorrect Chain Size: Using the wrong size chain for your chainsaw can lead to derailment. I once tried to use a chain that was slightly too long, and it kept coming off no matter how much I tightened it.
Expert Fixes: Keeping the Chain on Track
- Check and Adjust Chain Tension: Ensure the chain is properly tensioned, as described in section 2.
- Inspect the Sprocket:
- Location: The sprocket is located behind the clutch.
- Visual Inspection: Inspect the sprocket for any signs of wear or damage, such as rounded teeth or cracks.
- Replacement: If the sprocket is worn, replace it with a new one.
- Technical Requirement: Use the correct sprocket for your chain’s pitch. The Stihl 021 typically uses a 3/8″ pitch sprocket.
- Inspect the Bar:
- Visual Inspection: Inspect the bar for any signs of damage, such as bends, cracks, or burrs.
- Bar Dresser: Use a bar dresser to remove any burrs or sharp edges from the bar.
- Bar Rotation: Rotate the bar periodically to ensure even wear.
- Replacement: If the bar is severely damaged, replace it with a new one.
- Verify Chain Size:
- Check the Chain Specifications: Verify that the chain is the correct size for your chainsaw. The Stihl 021 typically uses a 3/8″ pitch, 0.050″ gauge chain with a specific number of drive links depending on the bar length.
- Consult the Owner’s Manual: Refer to your owner’s manual for the correct chain specifications.
- Unique Insight: A trick to prevent chain derailment is to use a chain catcher. A chain catcher is a small piece of metal or plastic that is attached to the chainsaw near the bar. It helps to prevent the chain from flying off if it derails. Most Stihl 021’s come with one pre-installed.
5. The Biting Blues: Chain Not Cutting Straight
If your chain is not cutting straight, it can be a sign of several underlying problems.
The Root Cause
- Unevenly Sharpened Chain: If the cutters on one side of the chain are sharper than the cutters on the other side, the chain will pull to one side.
- Damaged Bar: A bent or twisted bar can also cause the chain to cut crooked.
- Incorrect Depth Gauge Settings: If the depth gauges are not set correctly, the chain will not cut straight.
- Worn Bar Rails: Over time, the rails on the bar can wear unevenly, causing the chain to cut crooked.
Expert Fixes: Straightening Out the Cut
- Sharpen the Chain Evenly:
- Consistent Filing: Ensure that you file each cutter the same amount and at the same angle.
- Check Cutter Length: Use a caliper to measure the length of each cutter. They should all be approximately the same length.
- Correct Any Imbalances: If you notice any imbalances, correct them by filing the shorter cutters until they are the same length as the longer cutters.
- Inspect and Repair the Bar:
- Visual Inspection: Inspect the bar for any signs of damage, such as bends, twists, or uneven wear.
- Bar Dresser: Use a bar dresser to straighten the bar and remove any burrs or sharp edges.
- Bar Rails: Check the bar rails for wear. If they are worn unevenly, you may need to replace the bar.
- Adjust Depth Gauges:
- Depth Gauge Tool: Use a depth gauge tool to check the height of the depth gauges.
- Flat File: Use a flat file to adjust the height of the depth gauges.
- Consistent Settings: Ensure that all the depth gauges are set to the same height.
- Unique Insight: A trick to diagnose a crooked-cutting chain is to make a test cut in a piece of softwood. If the cut is not straight, examine the chips produced by the chain. If the chips are larger on one side than the other, it indicates that the cutters on that side are sharper.
Advanced Chain Maintenance and Troubleshooting
Beyond the basic fixes, here are some advanced techniques I’ve picked up over the years:
Chain Grinding: The Art of Precision
For chains that are severely damaged or have been sharpened incorrectly multiple times, chain grinding might be necessary. This involves using a specialized grinding wheel to reshape the cutters and restore the chain to its original specifications.
- When to Grind:
- Severely damaged cutters.
- Inconsistent cutter lengths.
- Incorrect sharpening angles.
- Rounded or worn cutting edges.
- Tools Required:
- Chainsaw chain grinder.
- Grinding wheels (various grits).
- Safety glasses.
- Gloves.
- Steps:
- Secure the Chain: Place the chain in the chain grinder.
- Select the Correct Grinding Wheel: Use a grinding wheel that is appropriate for your chain’s pitch and gauge.
- Adjust the Grinder Settings: Adjust the grinder settings to match the chain’s specifications, including the sharpening angle, depth gauge setting, and cutter length.
- Grind Each Cutter: Grind each cutter carefully, ensuring that you remove only a small amount of material at a time.
- Maintain Consistency: It’s crucial to grind each cutter the same amount to ensure even cutting.
- Cool the Chain: Use a coolant to prevent the chain from overheating during grinding.
- Inspect the Chain: After grinding, inspect the chain for any signs of damage or imperfections.
- Technical Requirement: Chain grinding requires a specialized grinder and a thorough understanding of chain geometry. It’s best left to experienced professionals or those with advanced chainsaw maintenance skills.
- Data Point: A properly ground chain should have a consistent cutter length and a sharp, well-defined cutting edge.
Understanding Wood Types and Their Impact on Chain Wear
Different types of wood have different densities and abrasive properties, which can significantly impact chain wear.
- Hardwoods vs. Softwoods:
- Hardwoods: Oak, maple, hickory, and other hardwoods are denser and more abrasive than softwoods. They require sharper chains and more frequent sharpening.
- Softwoods: Pine, fir, spruce, and other softwoods are less dense and less abrasive than hardwoods. They are easier to cut and cause less wear on the chain.
- Wood Moisture Content:
- Green Wood: Green wood (freshly cut wood) has a high moisture content, which can make it easier to cut but can also cause the chain to dull more quickly due to the increased friction.
- Dry Wood: Dry wood has a lower moisture content, which can make it more difficult to cut but can also reduce chain wear.
- Technical Requirement: When cutting hardwoods, use a chain with a more aggressive cutting angle and sharpen it more frequently. When cutting green wood, use a chain with a lower cutting angle to reduce friction.
- Data Point: The moisture content of green wood can range from 30% to over 100%, while the moisture content of dry wood is typically below 20%.
Chain Selection: Choosing the Right Chain for the Job
Not all chains are created equal. Choosing the right chain for the job can significantly improve cutting performance and extend chain life.
- Chain Pitch: The pitch is the distance between three consecutive rivets on the chain, divided by two. The Stihl 021 typically uses a 3/8″ pitch chain.
- Chain Gauge: The gauge is the thickness of the drive links that fit into the bar groove. The Stihl 021 typically uses a 0.050″ gauge chain.
- Chain Type:
- Full Chisel: Full chisel chains have square-cornered cutters that are very aggressive and fast-cutting. They are best suited for experienced users and clean wood.
- Semi-Chisel: Semi-chisel chains have rounded-cornered cutters that are less aggressive but more durable than full chisel chains. They are a good choice for general-purpose cutting and dirty wood.
- Low-Profile: Low-profile chains have smaller cutters and a lower kickback risk. They are a good choice for beginners and those who are concerned about safety.
- Technical Requirement: Always use a chain that is compatible with your chainsaw’s pitch and gauge. Using the wrong size chain can damage the chainsaw and create a safety hazard.
- Unique Insight: I’ve found that using a semi-chisel chain is a good compromise between cutting speed and durability for most firewood cutting tasks.
Safety First: Protecting Yourself While Using a Chainsaw
Chainsaw use is inherently dangerous. Always prioritize safety and wear appropriate personal protective equipment (PPE).
Essential PPE
- Eye Protection: Safety glasses or a face shield are essential to protect your eyes from flying debris.
- Hearing Protection: Chainsaws are very loud. Wear earplugs or earmuffs to protect your hearing.
- Head Protection: A hard hat is essential to protect your head from falling branches or debris.
- Hand Protection: Wear sturdy gloves to protect your hands from cuts and vibrations.
- Leg Protection: Chainsaw chaps or pants are essential to protect your legs from accidental cuts.
- Foot Protection: Wear sturdy boots with steel toes to protect your feet from falling logs and chainsaw cuts.
Safe Cutting Practices
- Read the Owner’s Manual: Before using your chainsaw, read the owner’s manual carefully and understand all the safety precautions.
- Inspect the Chainsaw: Before each use, inspect the chainsaw for any signs of damage or wear.
- Clear the Work Area: Clear the work area of any obstacles, such as rocks, branches, or debris.
- Maintain a Firm Grip: Always maintain a firm grip on the chainsaw with both hands.
- Keep Your Balance: Maintain your balance and avoid cutting above your head.
- Be Aware of Kickback: Kickback is a sudden and violent upward or backward movement of the chainsaw. Be aware of the risk of kickback and take steps to avoid it.
- Never Cut Alone: Always cut with a partner or let someone know where you will be cutting.
- Take Breaks: Take frequent breaks to avoid fatigue.
- Stay Sober: Never operate a chainsaw under the influence of alcohol or drugs.
Case Study: Analyzing Wood Strength and Safety
I remember a project where I was helping clear a property of dead oak trees. Oak, as we know, is a hardwood, and dead oak is even more unpredictable. I meticulously analyzed the wood for signs of rot and weakness. This involved using a moisture meter to check the moisture content of the wood (anything above 25% signaled potential rot) and visually inspecting for cracks or fungal growth.
In one instance, a seemingly solid oak log revealed significant internal rot upon closer inspection. Had I proceeded without caution, the log could have shattered during cutting, posing a serious safety risk. This experience reinforced the importance of thoroughly assessing the wood before cutting and adjusting cutting techniques accordingly.
I also found that using a full chisel chain on the dry, dead oak significantly increased the risk of kickback. Switching to a semi-chisel chain and reducing the depth gauge settings improved control and reduced the risk of kickback without sacrificing cutting efficiency.
Data-Backed Approach to Firewood Drying
One of the most common challenges for firewood producers is achieving the optimal moisture content for efficient burning. Air-drying is the most common method, but it can be slow and unpredictable.
I conducted a small-scale experiment to determine the drying rates of different wood species in my local climate. I measured the moisture content of freshly cut oak, maple, and pine logs and then stacked them in a well-ventilated area. I monitored the moisture content of the logs over several months, using a moisture meter.
Here’s what I found:
- Oak: Took the longest to dry, requiring approximately 12 months to reach a moisture content below 20%.
- Maple: Dried slightly faster than oak, requiring approximately 10 months to reach a moisture content below 20%.
- Pine: Dried the fastest, requiring approximately 6 months to reach a moisture content below 20%.
These findings highlighted the importance of proper wood stacking and ventilation for efficient drying. I also learned that using a wood moisture meter is essential for determining when the firewood is ready to burn.
Data Point: Firewood with a moisture content below 20% burns most efficiently and produces the least amount of smoke.
