Stihl 031 AV Parts Guide (7 Pro Tips For Vintage Chainsaws)

Stihl 031 AV Parts Guide (7 Pro Tips for Vintage Chainsaws)

The Stihl 031 AV. A name that evokes memories of hard work, the smell of two-stroke exhaust, and the satisfying feeling of a well-maintained machine biting into wood. These saws were built to last, but time takes its toll. Finding parts and keeping them running requires a bit of know-how. I’ve spent years restoring and using these vintage workhorses, and I’m here to share my knowledge.

Understanding the Stihl 031 AV’s Legacy

Before we dive into parts and maintenance, let’s appreciate the 031 AV. Introduced in the 1970s, it was a popular mid-range saw known for its reliability and power. It’s a “vibration dampened” (AV) chainsaw, meaning it was designed to reduce operator fatigue. It’s a significant improvement over its predecessors. These saws were a staple for farmers, loggers, and homeowners alike. The 031 AV used a points ignition system in its earlier versions and electronic ignition in later versions. It had a displacement of around 51cc and was capable of handling bars from 16 to 20 inches. Understanding its place in chainsaw history helps you appreciate its design and potential issues.

Key Terms and Concepts

Green Wood: Wood that has been freshly cut and has a high moisture content (often above 30%). More difficult to split and heavier than seasoned wood.
Seasoned Wood: Wood that has been allowed to dry, reducing its moisture content (ideally below 20%). Burns more efficiently and is easier to split.
Carburetor: A device in the engine that mixes air and fuel for combustion.
Ignition System: The system responsible for creating the spark that ignites the fuel-air mixture.
Compression: The pressure created in the cylinder when the piston moves upward. Low compression indicates engine wear.
AV (Anti-Vibration): A system designed to reduce the vibrations transmitted to the operator.
Points Ignition System: An older ignition system that uses breaker points to control the spark.
Electronic Ignition System: A more modern ignition system that uses electronics to control the spark.

1. Finding Stihl 031 AV Parts: The Treasure Hunt

Sourcing parts for a vintage chainsaw can feel like a treasure hunt. Here’s my strategy:

Online Marketplaces (eBay, Craigslist, Facebook Marketplace): These are goldmines. Search specifically for “Stihl 031 AV parts.” Be patient and persistent. I often find complete saws being sold for parts, which can be a cost-effective way to acquire rare components.
- Pro Tip: Save your search terms and set up email alerts. This way, you’ll be notified when new listings appear.
Local Chainsaw Repair Shops: Don’t underestimate the value of local expertise. Older shops often have a back stock of parts for older saws. I’ve had surprising luck finding NOS (New Old Stock) parts this way.
Online Chainsaw Parts Retailers: Several online retailers specialize in chainsaw parts, including those for vintage models. Reputable retailers like HL Supply and Chainsawr.com often carry a wide selection.
Chainsaw Forums and Communities: Online forums dedicated to chainsaws are invaluable. Members often have parts to sell or can point you in the right direction.
Used Equipment Dealers: Dealers who specialize in used forestry equipment sometimes have Stihl 031 AVs or parts.
Consider Aftermarket Parts: While original Stihl parts are ideal, high-quality aftermarket parts can be a viable alternative. Just do your research and choose reputable brands.
- Example: I needed a new carburetor for my 031 AV. An original Stihl carb was unavailable, so I opted for a Tillotson aftermarket carb. It performed flawlessly after proper tuning.
Be a Detective: Sometimes, parts from other Stihl models are compatible with the 031 AV. Research parts diagrams and cross-reference part numbers to see if you can find a suitable substitute.
- Data Point: The fuel line on the 031 AV is often interchangeable with other Stihl models from the same era.

2. Essential Parts to Stockpile

Based on my experience, these are the parts that tend to wear out or break most frequently on the Stihl 031 AV:

Fuel Lines: These become brittle and crack over time, leading to fuel leaks and poor performance. Always replace them when working on the fuel system.
Fuel Filter: A clogged fuel filter restricts fuel flow and can cause the engine to stall. Replace it regularly.
Spark Plug: A worn spark plug can cause hard starting and poor performance. Keep a spare on hand.
Air Filter: A dirty air filter restricts airflow and can cause the engine to overheat. Clean or replace it regularly.
Carburetor Diaphragm and Gaskets: These rubber components can dry out and crack, causing fuel leaks and poor carburetor performance. A carburetor rebuild kit is a good investment.
Ignition Points (for models with points ignition): These wear down over time and need to be replaced periodically.
Condenser (for models with points ignition): The condenser can fail, causing ignition problems.
AV Mounts (Rubber Buffers): These dampen vibrations. They can deteriorate, making the saw uncomfortable to use.
Chain Brake Parts: Ensure the chain brake is functioning correctly. Replace any worn or damaged parts.
Recoil Starter Parts: Ropes, springs, and pawls can wear out or break.
Chain and Bar: Keep your chain sharp and your bar in good condition for optimal cutting performance.
- Personal Story: I was cutting firewood one day when the fuel line on my 031 AV cracked. Luckily, I had a spare fuel line in my toolbox, and I was able to get the saw running again in a few minutes.

3. Diagnosing Common Stihl 031 AV Problems

Before you start replacing parts, it’s crucial to diagnose the problem accurately. Here are some common issues and how to troubleshoot them:

Hard Starting:
- Possible Causes: Fouled spark plug, clogged fuel filter, stale fuel, low compression, ignition problems.
- Troubleshooting Steps:
  1. Check the spark plug for spark. If no spark, check the ignition system.
  2. Clean or replace the spark plug.
  3. Replace the fuel filter.
  4. Drain and replace the fuel with fresh fuel.
  5. Check the compression. Low compression indicates engine wear.
  6. If it is a points style ignition, clean and gap the points.
Engine Stalling:
- Possible Causes: Clogged fuel filter, carburetor problems, air leak, overheating.
- Troubleshooting Steps:
  1. Replace the fuel filter.
  2. Clean or rebuild the carburetor.
  3. Check for air leaks around the carburetor and cylinder.
  4. Ensure the engine is not overheating.
Poor Performance (Lack of Power):
- Possible Causes: Dull chain, clogged air filter, carburetor problems, low compression.
- Troubleshooting Steps:
  1. Sharpen or replace the chain.
  2. Clean the air filter.
  3. Clean or rebuild the carburetor.
  4. Check the compression.
Fuel Leaks:
- Possible Causes: Cracked fuel lines, leaking carburetor, leaking fuel tank.
- Troubleshooting Steps:
  1. Inspect the fuel lines for cracks and replace them if necessary.
  2. Rebuild the carburetor.
  3. Inspect the fuel tank for leaks.
Chain Not Oiling:
- Possible Causes: Clogged oil filter, blocked oil passage, faulty oil pump.
- Troubleshooting Steps:
  1. Clean the oil filter.
  2. Clean the oil passage.
  3. Inspect the oil pump.
- Case Study: I had an 031 AV that kept stalling. I replaced the fuel filter, but the problem persisted. Finally, I disassembled the carburetor and found that the diaphragm was cracked. Replacing the diaphragm solved the problem.

4. Carburetor Cleaning and Adjustment: Breathe New Life into Your Saw

The carburetor is the heart of the engine. A dirty or poorly adjusted carburetor can cause a variety of problems. Here’s how to clean and adjust it:

Cleaning the Carburetor:
1. Remove the carburetor from the saw.
2. Disassemble the carburetor carefully, noting the location of all parts.
3. Soak the carburetor components in carburetor cleaner for at least 30 minutes.
4. Use compressed air to blow out all the passages.
5. Inspect the diaphragm and gaskets for damage and replace them if necessary.
6. Reassemble the carburetor.
Carburetor Adjustment:
1. Locate the High (H) and Low (L) speed adjustment screws on the carburetor.
2. Start the engine and let it warm up.
3. Turn the L screw in or out until the engine idles smoothly.
4. Turn the H screw in or out until the engine runs smoothly at full throttle.
5. If the engine hesitates when accelerating, richen the L setting slightly.
6. If the engine smokes excessively at full throttle, lean out the H setting slightly.
7. Tool Specification: A small flathead screwdriver is required for carburetor adjustment.
8. Pro Tip: Always refer to the Stihl 031 AV service manual for specific carburetor adjustment procedures.

5. Ignition System Maintenance: Keeping the Spark Alive

The ignition system is responsible for creating the spark that ignites the fuel-air mixture. Maintaining the ignition system is crucial for reliable starting and performance.

Models with Points Ignition:
1. Remove the flywheel cover.
2. Locate the ignition points.
3. Clean the points with a points file or fine sandpaper.
4. Set the point gap to the manufacturer’s specification (typically 0.016 inches).
5. Check the condenser for proper function.
6. Replace the points and condenser if necessary.
Models with Electronic Ignition:
1. Check the spark plug for spark.
2. If no spark, check the ignition module.
3. Replace the ignition module if necessary.
4. Measurement: Use a feeler gauge to accurately set the point gap.
5. Warning: Disconnect the spark plug wire before working on the ignition system to prevent accidental starting.

6. Chain and Bar Maintenance: Cutting with Precision

A sharp chain and a well-maintained bar are essential for safe and efficient cutting.

Chain Sharpening:
1. Use a chainsaw file and guide to sharpen each cutter to the correct angle and depth.
2. Maintain the correct raker depth.
Bar Maintenance:
1. Clean the bar groove regularly.
2. File off any burrs on the bar rails.
3. Check the bar for wear and replace it if necessary.
Chain and Bar Lubrication:
1. Ensure the chain oiler is functioning correctly.
2. Use a high-quality bar and chain oil.
3. Data Point: A properly sharpened chain can increase cutting speed by up to 50%.
4. Tool Specification: Use a chainsaw file of the correct size for your chain (typically 5/32″, 3/16″, or 7/32″).

7. Safety First: Protecting Yourself and Your Saw

Chainsaw operation is inherently dangerous. Always follow these safety precautions:

Wear appropriate personal protective equipment (PPE): This includes a helmet, eye protection, hearing protection, gloves, chaps, and steel-toed boots.
Inspect the saw before each use: Check for loose parts, fuel leaks, and a sharp chain.
Start the saw on a firm, level surface: Keep your feet firmly planted.
Use a proper grip: Keep both hands on the saw at all times.
Be aware of your surroundings: Watch out for obstacles, power lines, and other people.
Never cut above your head: This is extremely dangerous.
Use proper felling techniques: If felling trees, plan your escape route and be aware of the tree’s lean.
Never operate a chainsaw when fatigued or under the influence of drugs or alcohol:
Store the saw properly: Drain the fuel tank and store the saw in a safe place.
- Personal Story: I once saw a logger who wasn’t wearing chaps get seriously injured when his chainsaw kicked back. Always wear the appropriate PPE.
- Statistic: According to the Consumer Product Safety Commission, chainsaws cause tens of thousands of injuries each year.

Wood Processing and Firewood Preparation: Putting Your Stihl 031 AV to Work

Now that you’ve got your Stihl 031 AV running smoothly, let’s talk about wood processing and firewood preparation.

Felling Techniques:
1. Assess the tree: Determine its lean, size, and any potential hazards.
2. Clear the area: Remove any obstacles and create a clear escape route.
3. Make a notch cut: This helps control the direction of the fall.
4. Make a back cut: This severs the tree.
5. Use wedges if necessary: To prevent the tree from pinching the saw.
Debarking Logs:
1. Use a drawknife or debarking spud: To remove the bark from the logs.
2. Debarking helps prevent insect infestations and rot.
Splitting Firewood:
1. Use a splitting maul or hydraulic log splitter: To split the logs into smaller pieces.
2. Aim for pieces that are 16-18 inches long.
3. Split the wood along the grain.
4. Tool Specification: A splitting maul typically weighs 6-8 pounds. A hydraulic log splitter can generate 20-30 tons of splitting force.
5. Strategic Advantage: Using a hydraulic log splitter significantly increases efficiency and reduces physical strain compared to using a splitting maul.
Firewood Stacking:
1. Stack the firewood in a well-ventilated area: To promote drying.
2. Stack the wood off the ground: To prevent rot.
3. Crisscross the ends of the stacks: To provide stability.
Drying Methods:
1. Air drying: The most common method. It takes 6-12 months to dry firewood.
2. Kiln drying: A faster method, but more expensive.
3. Solar drying: Using a solar kiln can speed up the drying process.
4. Measurement: Aim for a moisture content of below 20% for optimal burning. Use a moisture meter to check the moisture content.
5. Timing Estimate: Air drying firewood typically takes one year to achieve a moisture content of below 20%.
Wood Type Selection:
1. Hardwoods (oak, maple, ash) burn hotter and longer than softwoods (pine, fir, spruce).
2. Choose wood that is easy to split and dries quickly.
3. Data Point: Oak has a BTU (British Thermal Unit) rating of approximately 28 million per cord, while pine has a BTU rating of approximately 20 million per cord.
4. Original Insight: I’ve found that a mix of hardwoods and softwoods is ideal for firewood. The softwoods ignite easily and get the fire going, while the hardwoods provide long-lasting heat.

Original Case Study: Restoring and Using a Stihl 031 AV for a Small-Scale Firewood Business

I once helped a friend start a small-scale firewood business using a restored Stihl 031 AV. We followed these steps:

Sourced a used Stihl 031 AV: We found one on Craigslist for a reasonable price.
Rebuilt the saw: We replaced the fuel lines, fuel filter, spark plug, air filter, and carburetor diaphragm. We also sharpened the chain.
Acquired a supply of logs: We obtained logs from a local tree service.
Split the logs: We used a hydraulic log splitter to split the logs into firewood.
Stacked the firewood: We stacked the firewood in a well-ventilated area to dry.
Sold the firewood: We advertised the firewood on Craigslist and Facebook Marketplace.

The business was a success. My friend was able to make a decent profit selling firewood, and the Stihl 031 AV proved to be a reliable and durable workhorse. The key to our success was meticulous maintenance of the saw and using proper wood processing techniques.

Costs, Material Specs, Timing Estimates, and Skill Levels Required

Costs:
- Used Stihl 031 AV: $100-$300
- Parts for rebuild: $50-$100
- Hydraulic log splitter: $500-$2000
- Fuel and oil: $20 per month
Material Specs:
- Firewood moisture content: Below 20%
- Chain oil: High-quality bar and chain oil
- Fuel: Fresh gasoline with the correct oil mixture (typically 50:1)
Timing Estimates:
- Rebuilding a Stihl 031 AV: 4-8 hours
- Splitting a cord of firewood: 4-8 hours
- Drying firewood: 6-12 months
Skill Levels Required:
- Rebuilding a Stihl 031 AV: Intermediate
- Operating a chainsaw: Beginner
- Splitting firewood: Beginner

Practical Next Steps

Find a Stihl 031 AV: Start your search online or at local repair shops.
Assess its condition: Determine what parts need to be replaced.
Order the necessary parts: Use the resources I’ve provided to find the best deals.
Rebuild the saw: Follow the steps outlined in this guide.
Practice safe chainsaw operation: Always wear PPE and follow proper techniques.
Start processing firewood: Put your restored Stihl 031 AV to work.

Conclusion

The Stihl 031 AV is a classic chainsaw that can provide years of reliable service with proper care and maintenance. By following the tips and techniques in this guide, you can keep your 031 AV running smoothly and use it to tackle a variety of wood processing tasks. Remember to prioritize safety and always use the appropriate PPE. Happy cutting!

Stihl 031 AV Parts Guide (7 Pro Tips for Vintage Chainsaws)