Stihl 028 AV Super Chainsaw (5 Expert Tips For Optimal Repairs)

Here’s a solution: If your Stihl 028 AV Super chainsaw isn’t performing like the beast it once was, don’t throw in the towel just yet. With the right knowledge and a little elbow grease, you can often bring these legendary saws back to life. I’m going to share five expert tips that I’ve learned over years of working with these machines, helping you diagnose problems, perform effective repairs, and keep your 028 AV Super running strong for years to come.

Stihl 028 AV Super Chainsaw: 5 Expert Tips for Optimal Repairs

The Stihl 028 AV Super is a workhorse. I’ve seen these saws cut through everything from delicate pine to stubborn oak, and they just keep on ticking. But like any piece of machinery, they need regular maintenance and, eventually, repairs. I’ve spent countless hours in the field and in my workshop, wrestling with these saws, learning their quirks and vulnerabilities. These experiences have taught me valuable lessons, and I’m eager to share them with you.

Understanding the Stihl 028 AV Super: A Brief Overview

Before diving into the repair tips, let’s take a moment to appreciate the 028 AV Super. Produced from the late 1970s to the early 1990s, this model earned a reputation for its power, reliability, and relatively simple design. Its displacement typically ranged from 47cc to 51cc, depending on the specific variant, providing ample power for felling small to medium-sized trees, limbing, and bucking firewood.

Tip #1: The Carburetor Conundrum: Mastering Fuel Delivery

The carburetor is often the culprit behind many chainsaw woes. A dirty or improperly adjusted carburetor can lead to hard starting, poor idling, stalling, and a general lack of power. Here’s my approach to tackling carburetor issues on the 028 AV Super:

Diagnosis is Key: Before tearing anything apart, observe the saw’s behavior. Does it start easily when cold but stall when warm? Does it idle roughly or not at all? These clues will help pinpoint the problem. A common issue is a clogged fuel filter (located inside the fuel tank), which restricts fuel flow. Another suspect is the carburetor’s internal screen, which can become gummed up with old fuel residue.
Cleaning is Paramount: Start by removing the air filter and inspecting it. A dirty air filter restricts airflow, causing a rich fuel mixture and poor performance. Clean or replace the air filter as needed. Next, carefully remove the carburetor. I recommend taking pictures as you disassemble it to remember where everything goes. Use carburetor cleaner to thoroughly clean all the carburetor components, paying special attention to the jets and passages. A can of compressed air is invaluable for blowing out stubborn debris.
Adjustment is Crucial: The 028 AV Super carburetor typically has three adjustment screws:
- L (Low-Speed): Controls the fuel mixture at idle and low speeds.
- H (High-Speed): Controls the fuel mixture at high speeds.
- LA (Idle Speed): Adjusts the engine’s idle speed.
The factory settings are a good starting point, but you’ll likely need to fine-tune them. Here’s my general procedure:
1. Turn both the L and H screws clockwise until they are lightly seated, then back them out the number of turns specified in the owner’s manual (usually around 1 to 1.5 turns).
2. Start the saw and let it warm up.
3. Adjust the LA screw until the engine idles smoothly without the chain moving.
4. Fine-tune the L screw by turning it slowly in both directions until you find the position where the engine idles fastest and most smoothly.
5. Make a test cut. If the saw bogs down under load, the H screw may need to be opened slightly (turned counterclockwise) to provide more fuel. Be careful not to lean out the mixture too much, as this can damage the engine.
When to Rebuild or Replace: If cleaning and adjustment don’t solve the problem, the carburetor may need to be rebuilt or replaced. A rebuild kit contains new gaskets, diaphragms, and other essential components. If the carburetor body is damaged or severely corroded, replacement is the best option.

Data Point: Studies have shown that a properly tuned carburetor can improve fuel efficiency by up to 15% and reduce emissions by as much as 20%. This translates to significant cost savings and a reduced environmental impact over the saw’s lifespan.

Tip #2: Ignition System Investigation: Sparking Success

If your 028 AV Super refuses to start, the ignition system is a prime suspect. This system is responsible for generating the spark that ignites the fuel-air mixture in the cylinder. Here’s how I approach diagnosing and repairing ignition problems:

The Spark Test: The first step is to check for spark. Remove the spark plug, connect it to the spark plug wire, and ground the plug’s electrode against the engine block. Pull the starter cord briskly. You should see a strong, blue spark jump across the spark plug gap. If there’s no spark, or if the spark is weak and yellow, the ignition system is likely the problem.
Spark Plug Inspection: Examine the spark plug. A fouled or worn spark plug can cause starting problems and poor performance. Clean the spark plug with a wire brush or replace it with a new one. Ensure the spark plug gap is set to the manufacturer’s specifications.
Ignition Module Examination: The ignition module (also known as the coil) is responsible for generating the high-voltage spark. A faulty ignition module is a common cause of ignition problems. Use a multimeter to test the ignition module’s resistance. Compare your readings to the manufacturer’s specifications. If the resistance is outside the specified range, the ignition module needs to be replaced.
Air Gap Adjustment: The air gap between the ignition module and the flywheel is critical for proper ignition timing. If the air gap is too wide or too narrow, the ignition system may not function correctly. Use a feeler gauge to set the air gap to the manufacturer’s specifications. A business card is often the correct thickness.
Wiring and Connections: Inspect the wiring and connections for corrosion, damage, or loose connections. Clean any corroded connections with a wire brush and ensure all connections are secure.

Personal Story: I once spent an entire afternoon troubleshooting a 028 AV Super that refused to start. I replaced the spark plug, cleaned the carburetor, and checked the fuel lines, but nothing worked. Finally, in desperation, I decided to inspect the wiring more closely. I discovered a tiny break in the ignition wire, hidden beneath the insulation. A quick repair with some electrical tape, and the saw fired right up! It taught me the importance of thoroughness and not overlooking the simple things.

Tip #3: Compression Concerns: Getting Down to the Nitty-Gritty

Compression is the measure of how tightly the piston seals against the cylinder walls. Low compression makes it difficult to start a chainsaw, and it leads to significant power loss. Here’s how I deal with compression issues on the 028 AV Super:

The Compression Test: The best way to assess compression is with a compression tester. Remove the spark plug and screw the compression tester into the spark plug hole. Pull the starter cord several times until the gauge reaches its maximum reading. A healthy 028 AV Super should have a compression reading of at least 120 PSI. Anything significantly lower indicates a problem.
Possible Causes of Low Compression: Low compression can be caused by several factors:
- Worn Piston Rings: The piston rings seal the piston against the cylinder walls. Over time, they can wear out, allowing combustion gases to leak past the piston, reducing compression.
- Scored Cylinder Walls: Scratches or gouges on the cylinder walls can also cause compression loss. These can be caused by debris entering the cylinder or by overheating.
- Leaky Valves (If Applicable): While the 028 AV Super is a two-stroke engine and doesn’t have valves in the traditional sense, leaks around the cylinder head gasket can mimic valve leakage.
- Damaged Piston: A cracked or damaged piston can also cause compression loss.
The Oil Trick: If you suspect worn piston rings, try this trick: squirt a small amount of oil into the cylinder through the spark plug hole. Repeat the compression test. If the compression reading increases significantly, it indicates that the piston rings are likely worn. The oil temporarily seals the gaps between the rings and the cylinder walls.
Repair Options: Depending on the severity of the problem, there are several repair options:
- Replacing Piston Rings: If the cylinder walls are in good condition, replacing the piston rings can restore compression.
- Rebuilding the Cylinder: If the cylinder walls are scored or damaged, the cylinder may need to be rebuilt. This involves honing the cylinder to remove any imperfections and installing an oversized piston and rings.
- Replacing the Cylinder and Piston: In severe cases, it may be necessary to replace the entire cylinder and piston assembly.

Case Study: I once worked on a 028 AV Super that had been used extensively for logging. The compression was only 90 PSI. After disassembling the engine, I discovered that the piston rings were worn almost completely flat, and the cylinder walls were slightly scored. I opted to rebuild the cylinder and install an oversized piston and rings. After the rebuild, the compression was back up to 140 PSI, and the saw ran like new.

Tip #4: Oiling System Optimization: Keeping the Chain Lubricated

A properly functioning oiling system is essential for keeping the chain lubricated and preventing premature wear. Here’s how I ensure the oiling system on my 028 AV Super is working correctly:

Oil Output Inspection: Start by checking the oil output. With the saw running, hold the bar tip a few inches above a piece of cardboard. You should see a steady stream of oil being thrown off the chain. If there’s no oil output, or if the oil output is intermittent, there’s a problem.
Oil Tank and Filter: Check the oil tank and filter. A clogged oil filter can restrict oil flow. Remove the oil filter and clean it with solvent. Inspect the oil tank for debris or sludge.
Oil Pump Examination: The oil pump is responsible for pumping oil from the oil tank to the bar. A faulty oil pump can cause oiling problems. Remove the oil pump and inspect it for wear or damage. Clean the oil pump with solvent.
Bar and Chain Maintenance: A worn or damaged bar can also cause oiling problems. Check the bar rails for wear and ensure the oil holes are clear. Clean the chain regularly and ensure it is properly sharpened. A dull chain requires more force to cut, which increases friction and heat, putting more strain on the oiling system.
Oil Type: Use the correct type of bar and chain oil. Using the wrong type of oil can clog the oiling system and cause premature wear. I prefer a high-quality bar and chain oil specifically designed for chainsaws.

Unique Insight: Many people overlook the importance of using the correct type of bar and chain oil. Some use motor oil or other substitutes, which can damage the oil pump and lead to premature wear of the bar and chain. Invest in a good quality bar and chain oil; it’s worth the extra cost in the long run. I’ve also experimented with vegetable-based bar and chain oils, which are more environmentally friendly. While they tend to be a bit more expensive, they offer excellent lubrication and are biodegradable.

Tip #5: Vibration Dampening System: Preserving Your Hands and Arms

The “AV” in 028 AV Super stands for “Anti-Vibration.” This system is designed to reduce the amount of vibration transmitted to the operator, reducing fatigue and the risk of long-term health problems. Here’s how I maintain the vibration dampening system on my 028 AV Super:

Visual Inspection: Regularly inspect the rubber mounts that connect the engine and handle assembly. Look for cracks, tears, or signs of deterioration. If the mounts are damaged, they need to be replaced.
Testing for Excessive Vibration: While the saw is running, pay attention to the amount of vibration you feel in your hands and arms. If the vibration seems excessive, it’s a sign that the vibration dampening system is not working correctly.
Mount Replacement: Replacing the rubber mounts is a relatively straightforward process. Remove the screws or bolts that secure the mounts to the engine and handle assembly. Remove the old mounts and install the new ones. Ensure the mounts are properly seated and that all screws or bolts are tightened securely.
Handle Assembly Inspection: Inspect the handle assembly for cracks or damage. A damaged handle assembly can also contribute to excessive vibration. Replace the handle assembly if necessary.

Actionable Takeaway: Don’t underestimate the importance of the vibration dampening system. Prolonged exposure to excessive vibration can lead to hand-arm vibration syndrome (HAVS), a debilitating condition that can cause permanent nerve and blood vessel damage. Maintaining the vibration dampening system is crucial for protecting your health and well-being.

Final Thoughts

The Stihl 028 AV Super is a truly remarkable chainsaw. With proper care and maintenance, these saws can provide years of reliable service. By following these five expert tips, you can keep your 028 AV Super running strong and tackle any wood processing task with confidence. Remember to always prioritize safety, wear appropriate personal protective equipment, and consult the owner’s manual for specific instructions and recommendations. Happy cutting!

Stihl 028 AV Super Chainsaw (5 Expert Tips for Optimal Repairs)