Stihl 021 Saw Maintenance Tips (5 Pro Hacks For Longevity)

If you follow my advice, you’ll keep your Stihl 021 chainsaw running strong for years, saving you money and headaches!

Stihl 021 Saw Maintenance Tips (5 Pro Hacks for Longevity)

The Stihl 021 is a workhorse. I’ve personally relied on this model for years in my own wood processing operation. But like any machine, it needs proper care to keep it running smoothly. I’ve seen firsthand how neglect can turn a reliable saw into a frustrating paperweight. These aren’t just generic tips; they’re the specific things I do to keep my Stihl 021 purring. This guide dives into five pro hacks that will significantly extend the life of your saw.

Understanding the Stihl 021: A Brief Overview

Before we dive into the hacks, let’s quickly recap what makes the Stihl 021 a great saw. The Stihl 021 is a lightweight, yet powerful chainsaw designed for homeowners and occasional users. Its compact size and ease of use make it ideal for tasks like pruning, limbing, and cutting small firewood. It typically features a 35.2 cc engine and a 14-16 inch bar, offering a good balance of power and maneuverability.

Engine: 35.2 cc two-stroke engine.
Bar Length: Typically 14-16 inches.
Weight: Around 10 pounds (without fuel and bar).
Typical Uses: Pruning, limbing, small firewood cutting.

Understanding these basics will help you appreciate the importance of the maintenance tips we’re about to cover.

Hack #1: Fuel Mix Perfection – The Heart of Your Saw

The fuel mix is arguably the most crucial aspect of Stihl 021 maintenance. I cannot stress this enough: using the wrong fuel mix will kill your saw faster than anything else. The Stihl 021, like most two-stroke engines, requires a precise blend of gasoline and two-stroke oil.

The Correct Ratio: The recommended fuel-to-oil ratio for the Stihl 021 is 50:1. This means 50 parts gasoline to 1 part two-stroke oil. Using a pre-mixed fuel like Stihl MotoMix can eliminate the guess work.
Why This Matters: Too little oil leads to insufficient lubrication, causing excessive wear and potential engine seizure. Too much oil can cause carbon buildup, leading to poor performance and eventual engine damage.
My Personal Experience: I once had a helper who consistently used a 40:1 mix “just to be safe.” While his intentions were good, the saw quickly started running poorly, smoking excessively, and eventually required a costly carburetor cleaning.
The Right Oil: Use a high-quality two-stroke oil specifically designed for air-cooled engines. Stihl’s own brand of two-stroke oil is a great choice, but other reputable brands will also work. Avoid using automotive two-stroke oil, as it’s not designed for the high temperatures and demands of a chainsaw engine.
The Right Gasoline: Use fresh, high-octane gasoline (minimum 89 octane). Ethanol-blended fuels can be problematic, as ethanol can absorb moisture and damage fuel lines and carburetor components. If you must use ethanol-blended fuel, use a fuel stabilizer to mitigate the potential damage.
Mixing Procedure: I always use a dedicated fuel mixing container with clear markings for both gasoline and oil. Pour the correct amount of oil into the container first, then add the gasoline. This helps ensure proper mixing. Shake the container vigorously for at least 30 seconds to ensure the oil and gasoline are thoroughly blended.
Storage: Store your fuel mix in a tightly sealed container in a cool, dark place. Fuel mix degrades over time, so it’s best to use it within 30 days. If you’re not going to use it within that timeframe, dispose of it properly.
Practical Tip: I write the date on the fuel container when I mix a new batch. This helps me keep track of how old the fuel is and avoid using stale fuel.
Metric Conversion: For those using metric measurements, a 50:1 ratio translates to 20 ml of oil per 1 liter of gasoline.
Real-World Example: A small-scale logger I know had recurring problems with his Stihl 021. After troubleshooting, we discovered he was using old, improperly mixed fuel. Once he switched to fresh fuel and followed the correct mixing procedure, his saw ran like new.

Takeaway: Always use the correct fuel mix (50:1) with high-quality two-stroke oil and fresh, high-octane gasoline. Mix fuel properly and store it in a sealed container, using it within 30 days.

Hack #2: Air Filter Vigilance – Breathing Easy for Power

A clean air filter is essential for optimal engine performance and longevity. A clogged air filter restricts airflow, causing the engine to run rich (too much fuel, not enough air). This leads to reduced power, increased fuel consumption, and potential engine damage.

Why it Matters: The Stihl 021’s engine needs a constant supply of clean air to burn fuel efficiently. A dirty air filter chokes the engine, making it work harder and shortening its lifespan.
Inspection Frequency: I recommend checking the air filter every time you refuel the saw. In dusty conditions, you may need to check it more frequently.
Cleaning Procedure:
1. Remove the air filter cover.
2. Carefully remove the air filter.
3. Inspect the filter for dirt, debris, and damage.
4. If the filter is only lightly soiled, gently tap it against a hard surface to dislodge loose dirt.
5. For more thorough cleaning, wash the filter in warm, soapy water. Use a mild detergent and avoid harsh chemicals.
6. Rinse the filter thoroughly with clean water.
7. Allow the filter to air dry completely before reinstalling it.
8. If the filter is torn or excessively dirty, replace it with a new one.
Types of Air Filters: The Stihl 021 typically uses a foam air filter. Some models may have a paper filter. Foam filters are washable and reusable, while paper filters should be replaced when they become too dirty.
My Personal Experience: I once neglected to clean the air filter on my Stihl 021 after a particularly dusty day of cutting firewood. The saw started running sluggishly, and I eventually realized the air filter was completely clogged. After cleaning the filter, the saw regained its power and ran smoothly again.
Oiling Foam Filters: Some people recommend lightly oiling foam air filters after cleaning. This helps trap dirt and debris. If you choose to oil your filter, use a special air filter oil, not regular engine oil. Apply the oil sparingly and squeeze out any excess.
Practical Tip: I keep a spare air filter on hand so I can quickly replace a dirty filter and continue working without interruption.
Cost Savings: Regularly cleaning or replacing your air filter can save you money in the long run by improving fuel efficiency and preventing engine damage. A new air filter typically costs between $5 and $15.
Real-World Example: A firewood seller I know had to replace the engine on his Stihl 021 because he never cleaned the air filter. He learned a valuable lesson about the importance of regular maintenance.

Takeaway: Check the air filter every time you refuel. Clean it regularly with warm, soapy water and allow it to dry completely. Replace it when necessary. A clean air filter ensures optimal engine performance and extends the life of your saw.

Hack #3: Chain Sharpening Mastery – Cutting with Precision and Safety

A sharp chain is essential for efficient cutting and safety. A dull chain forces you to apply more pressure, which can lead to kickback and other dangerous situations. A sharp chain cuts quickly and smoothly, reducing strain on the saw and the operator.

Why it Matters: A dull chain not only makes cutting more difficult, but it also increases the risk of accidents. A sharp chain bites into the wood easily, giving you more control over the saw.
Sharpening Frequency: I recommend sharpening the chain every time you refuel the saw, or more frequently if you’re cutting dirty or abrasive wood.
Sharpening Tools: You can sharpen the chain with a file and guide, an electric chain sharpener, or a bench grinder. I prefer using a file and guide for quick touch-ups in the field, and an electric chain sharpener for more thorough sharpening in the shop.
Filing Technique:
1. Secure the saw in a vise or clamp.
2. Use the correct size file for your chain (typically 5/32″ for the Stihl 021).
3. Place the file in the guide and position it on the cutter.
4. File each cutter at the correct angle (typically 30 degrees).
5. Maintain a consistent filing angle and depth.
6. File each cutter the same number of strokes.
7. Check the depth gauges and file them down if necessary.
Electric Chain Sharpeners: Electric chain sharpeners make sharpening faster and easier, but they can also remove more material from the chain. Be careful not to over-sharpen the chain.
My Personal Experience: I once tried to cut a large oak log with a dull chain. The saw kept bouncing and kicking back, and I quickly realized I was putting myself in danger. After sharpening the chain, the saw cut through the log with ease.
Chain Maintenance: In addition to sharpening, it’s important to keep the chain clean and lubricated. Remove any sawdust or debris from the chain after each use.
Chain Tension: Proper chain tension is also crucial for safety and performance. The chain should be snug on the bar, but not so tight that it binds. You should be able to pull the chain away from the bar slightly.
Practical Tip: I use a chain gauge to check the depth gauges and ensure they are at the correct height. This helps prevent kickback.
Cost Savings: Sharpening your own chain can save you money on replacement chains and professional sharpening services. A new chain typically costs between $20 and $40, while professional sharpening costs around $10 to $15.
Real-World Example: A tree service company I know has a dedicated chain sharpener on staff. This ensures that all of their saws are always cutting with sharp chains, improving efficiency and safety.

Takeaway: Sharpen your chain regularly to ensure efficient cutting and safety. Use the correct tools and techniques. Keep the chain clean, lubricated, and properly tensioned.

Hack #4: Bar and Chain Oiling – Keeping Things Smooth and Cool

Proper lubrication of the bar and chain is essential for preventing wear and tear and ensuring smooth cutting. The bar and chain oil reduces friction between the chain and the bar, preventing overheating and extending the life of both components.

Why it Matters: Without proper lubrication, the chain will quickly overheat and become dull. The bar will also wear down prematurely.
Oil Type: Use a high-quality bar and chain oil specifically designed for chainsaws. Avoid using motor oil or other substitutes, as they may not provide adequate lubrication. I prefer using a bar and chain oil with a tackifier additive, which helps the oil cling to the chain and bar.
Oil Reservoir: Check the oil reservoir level every time you refuel the saw. The oil reservoir should be full.
Oil Output: Adjust the oil output to match the cutting conditions. In hot weather or when cutting hard wood, you may need to increase the oil output. In cold weather or when cutting soft wood, you can reduce the oil output.
Cleaning: Regularly clean the bar and chain to remove sawdust and debris. Use a wire brush or a scraper to clean the bar groove and oil holes.
Bar Maintenance: Periodically flip the bar over to distribute wear evenly. Check the bar rails for wear and damage. If the rails are worn or damaged, replace the bar.
My Personal Experience: I once ran my Stihl 021 without enough bar and chain oil. The chain quickly overheated and became dull, and the bar started to smoke. I learned my lesson about the importance of proper lubrication.
Automatic Oilers: The Stihl 021 has an automatic oiler that dispenses oil to the bar and chain. Make sure the oiler is working properly. If it’s not, check the oil filter and oil lines for clogs.
Practical Tip: I keep a spare bar and chain on hand so I can quickly replace a worn or damaged bar and chain and continue working without interruption.
Cost Savings: Proper lubrication can extend the life of your bar and chain, saving you money on replacement parts. A new bar typically costs between $30 and $50, while a new chain costs between $20 and $40.
Real-World Example: A logging company I know uses a centralized oiling system to lubricate the bars and chains on all of their chainsaws. This ensures that all of their saws are always properly lubricated, improving efficiency and reducing downtime.

Takeaway: Use a high-quality bar and chain oil. Check the oil reservoir level every time you refuel. Adjust the oil output to match the cutting conditions. Clean the bar and chain regularly. Maintain the bar and replace it when necessary.

Hack #5: Spark Plug and Carburetor Care – Igniting Performance

The spark plug and carburetor are essential for proper engine combustion. A fouled spark plug or a dirty carburetor can cause the engine to run poorly or not start at all.

Why it Matters: The spark plug ignites the fuel-air mixture in the engine, while the carburetor regulates the amount of fuel that is mixed with the air. If either of these components is not working properly, the engine will not run efficiently.
Spark Plug Inspection: I recommend inspecting the spark plug every 25 hours of use. Remove the spark plug and inspect it for wear, damage, and carbon buildup.
Spark Plug Cleaning: If the spark plug is only lightly fouled, you can clean it with a wire brush or a spark plug cleaner.
Spark Plug Replacement: If the spark plug is worn, damaged, or heavily fouled, replace it with a new one. Use the correct spark plug for your Stihl 021 (typically a Bosch WSR6F or NGK BPMR7A).
Carburetor Cleaning: A dirty carburetor can cause the engine to run rich or lean, leading to poor performance and potential engine damage. If the engine is running poorly, try cleaning the carburetor.
Carburetor Adjustment: The Stihl 021 carburetor has three adjustment screws: the high-speed screw (H), the low-speed screw (L), and the idle speed screw (LA). These screws control the amount of fuel that is delivered to the engine at different speeds. Adjusting the carburetor can be tricky, so it’s best to consult a qualified mechanic if you’re not comfortable doing it yourself.
My Personal Experience: I once had a Stihl 021 that was difficult to start and ran poorly. After inspecting the spark plug, I found that it was heavily fouled with carbon. After replacing the spark plug, the saw started easily and ran smoothly again.
Fuel Filter: The fuel filter prevents dirt and debris from entering the carburetor. Replace the fuel filter every year or more frequently if you’re using dirty fuel.
Practical Tip: I keep a spare spark plug and fuel filter on hand so I can quickly replace them and continue working without interruption.
Cost Savings: Replacing a spark plug or fuel filter is relatively inexpensive and can save you money on more costly repairs down the road. A new spark plug typically costs between $5 and $10, while a new fuel filter costs around $5.
Real-World Example: A small engine repair shop I know recommends that all of their customers replace the spark plug and fuel filter on their chainsaws every year. This helps prevent engine problems and keeps the saws running smoothly.

Takeaway: Inspect the spark plug regularly and replace it when necessary. Clean the carburetor if the engine is running poorly. Replace the fuel filter every year. Proper spark plug and carburetor care ensures optimal engine combustion and performance.

Beyond the Hacks: Additional Maintenance Considerations

While these five hacks are crucial, there are other maintenance tasks that you should also consider to keep your Stihl 021 running smoothly.

Chain Brake Inspection: Regularly inspect the chain brake to ensure it’s working properly. The chain brake should stop the chain immediately when engaged.
Starter Rope and Recoil Spring: Inspect the starter rope and recoil spring for wear and damage. Replace them if necessary.
Muffler: Clean the muffler screen periodically to prevent clogging. A clogged muffler can reduce engine power.
Cooling Fins: Keep the cooling fins on the cylinder clean to prevent overheating.
Storage: When storing the saw for extended periods, drain the fuel tank and run the engine until it stalls. This prevents fuel from gumming up the carburetor.

Safety First: Always Prioritize Safe Practices

Before performing any maintenance on your Stihl 021, always disconnect the spark plug wire to prevent accidental starting. Wear appropriate safety gear, including gloves, eye protection, and hearing protection. Work in a well-ventilated area and avoid working on the saw while it’s hot.

Troubleshooting Common Stihl 021 Problems

Even with regular maintenance, you may encounter problems with your Stihl 021. Here are some common problems and their potential solutions:

Saw Won’t Start: Check the fuel level, spark plug, and air filter. Make sure the choke is engaged.
Saw Runs Poorly: Clean the air filter and carburetor. Replace the spark plug and fuel filter.
Saw Smokes Excessively: Use the correct fuel mix. Clean the air filter.
Chain Won’t Oil: Check the oil reservoir level. Clean the bar and chain. Check the oil filter and oil lines.
Chain Binds or Kicks Back: Sharpen the chain. Adjust the chain tension. Check the depth gauges.

The Value of Preventative Maintenance

Investing a little time and effort in preventative maintenance can save you a lot of money and frustration in the long run. By following these pro hacks and additional maintenance tips, you can keep your Stihl 021 running strong for years to come. I’ve seen too many saws end up in the repair shop (or worse, the trash) simply because of neglect. Don’t let that happen to your Stihl 021.

Final Thoughts: A Reliable Saw for Years to Come

The Stihl 021 is a reliable and versatile chainsaw that can handle a wide range of tasks. By following these maintenance tips, you can ensure that your Stihl 021 will continue to serve you well for years to come. Remember, a well-maintained saw is a safe and efficient saw. Take care of your Stihl 021, and it will take care of you.

Stihl 021 Saw Maintenance Tips (5 Pro Hacks for Longevity)