Stihl 064 Specs & Upgrades (Pump Mods For Better Wood Cutting)

From the time I was a kid, the smell of sawdust was like a siren’s call. Weekends weren’t spent in front of the TV, but out in the woods with my grandfather, learning the ancient art of felling trees and turning them into something useful. Maybe it was the challenge of mastering a roaring chainsaw, or the satisfaction of splitting a perfect piece of firewood, but I was hooked. Now, decades later, I’m still chasing that thrill, albeit with a little more knowledge and a lot more respect for safety.

One of the things I’ve learned is that a chainsaw is more than just a tool; it’s a finely tuned machine. And like any machine, it can be optimized for peak performance. That’s what brings me to the Stihl 064. It’s a beast of a saw, no doubt, but with a few tweaks, it can become a wood-cutting monster. In this guide, I’ll share everything I know about the Stihl 064, from its stock specs to some seriously effective pump modifications that can take your wood processing to the next level. We’ll dive deep into the technical side, so buckle up and let’s get started.

Stihl 064: A Technical Deep Dive

The Stihl 064 is a legend in the chainsaw world for good reason. It’s powerful, reliable, and built to last. But even a legend can benefit from a little refinement.

Stock Specifications: The Foundation

Before we start talking about upgrades, let’s establish a baseline. Here are the factory specifications for the Stihl 064:

Engine Displacement: 84.9 cc (5.18 cu in)
Engine Power: 4.8 kW (6.5 bhp) at 8,000 RPM
Weight (Powerhead Only): 7.3 kg (16.1 lbs)
Fuel Tank Capacity: 0.825 L (27.9 oz)
Oil Tank Capacity: 0.36 L (12.2 oz)
Recommended Bar Length: 45 cm to 75 cm (18″ to 30″)

These figures tell only part of the story. The real magic of the 064 lies in its robust construction and well-designed components. I’ve seen these saws running strong after decades of hard use.

Understanding the Oiling System

The oiling system is critical for chainsaw performance and longevity. It ensures the chain and bar are properly lubricated, reducing friction and preventing premature wear. The stock oil pump on the 064 is generally reliable, but it can be a bottleneck when pushing the saw to its limits, especially with longer bars or when cutting hardwoods.

Oil Pump Type: Automatic, adjustable
Oil Output: Varies with engine speed and adjustment setting
Adjustment Range: Typically allows for a 50-100% increase in oil output.

In my experience, the stock oil pump is often sufficient for general firewood cutting and smaller-diameter trees. However, when dealing with larger logs or harder wood species like oak or maple, the oil flow can become inadequate, leading to increased chain wear and potential bar damage. I remember one time I was cutting some old growth oak. The saw was bogging down and the chain was smoking. I quickly realized I needed to upgrade the oiler to properly cut the hardwood.

Common Issues with the Stock Oiling System

Insufficient Oil Flow: This is the most common complaint, especially with longer bars and hardwoods. The chain may appear dry, and you may notice excessive wear on the bar rails.
Oil Pump Failure: While relatively rare, the oil pump can fail due to wear and tear or debris contamination. Symptoms include a complete lack of oil flow or inconsistent lubrication.
Clogged Oil Passages: Sawdust and debris can accumulate in the oil passages, restricting oil flow. Regular cleaning and maintenance are essential to prevent this issue.
Worn Oil Pump Components: Over time, the oil pump piston, cylinder, and seals can wear, reducing the pump’s efficiency.

Upgrading the Oiling System: Pump Modifications for Enhanced Performance

Now, let’s get to the heart of the matter: upgrading the oiling system. Several modifications can significantly improve oil flow and ensure your Stihl 064 is properly lubricated, even under the most demanding conditions.

The “H.O.” High Output Oil Pump: A Popular Upgrade

One of the most popular upgrades is installing a high-output (“H.O.”) oil pump. These pumps are designed to deliver significantly more oil than the stock pump, providing superior lubrication for longer bars and hardwoods.

Increased Oil Flow: H.O. pumps typically increase oil flow by 50-100% compared to the stock pump.
Improved Lubrication: Ensures adequate lubrication, even with longer bars and hardwoods.
Reduced Chain and Bar Wear: Minimizes friction and wear, extending the life of your chain and bar.

Installation:

The installation process is relatively straightforward, but it requires some mechanical aptitude.

Remove the Existing Oil Pump: Disassemble the chainsaw to access the oil pump. This typically involves removing the clutch, sprocket, and oil tank.
Install the H.O. Oil Pump: Install the new H.O. oil pump in place of the old one. Ensure all components are properly aligned and secured.
Reassemble the Chainsaw: Reassemble the chainsaw, making sure all parts are correctly installed and tightened.
Adjust Oil Flow: Adjust the oil flow using the adjustment screw on the oil pump. Start with a moderate setting and increase as needed.

Personal Tip: When installing the H.O. pump, I always recommend replacing the oil lines as well. Old, brittle lines can restrict oil flow and negate some of the benefits of the upgraded pump.

DIY Oil Pump Modifications: The “MacGyver” Approach

For those who are feeling adventurous and have some mechanical skills, there are several DIY modifications you can make to the stock oil pump to increase oil flow. These modifications are not for the faint of heart, but they can be effective if done correctly.

1. Enlarging the Oil Pump Inlet and Outlet:

This modification involves carefully enlarging the inlet and outlet ports on the oil pump to increase the flow of oil.

Tools Required: Dremel tool with small grinding bits, drill with small drill bits, sandpaper, and a steady hand.
Procedure:
1. Disassemble the oil pump.
2. Using the Dremel tool, carefully enlarge the inlet and outlet ports. Be careful not to remove too much material, as this could weaken the pump.
3. Use the drill to enlarge any small passages within the pump body.
4. Smooth the enlarged ports with sandpaper to remove any sharp edges or burrs.
5. Reassemble the oil pump.

Important Note: This modification requires a high degree of precision and skill. If you are not comfortable with this type of work, it is best to leave it to a professional.

2. Modifying the Oil Pump Piston:

This modification involves modifying the oil pump piston to increase its stroke length, which increases the amount of oil it pumps with each stroke.

Tools Required: Dremel tool with small grinding bits, file, sandpaper, and a precise measuring tool (calipers).
Procedure:
1. Disassemble the oil pump.
2. Carefully grind or file down the top of the oil pump piston to increase its stroke length. Be careful not to remove too much material, as this could cause the piston to bind.
3. Smooth the modified piston with sandpaper to remove any sharp edges or burrs.
4. Reassemble the oil pump.

Important Note: This modification is even more complex than enlarging the oil pump ports. It requires a very precise touch and a thorough understanding of how the oil pump works.

3. Adjusting the Oil Pump Spring Tension:

This modification involves adjusting the tension of the oil pump spring to increase the pressure on the oil pump piston, which can increase oil flow.

Tools Required: Small pliers, screwdriver, and a vice.
Procedure:
1. Disassemble the oil pump.
2. Carefully clamp the oil pump spring in a vice.
3. Use the pliers and screwdriver to slightly compress the spring. Be careful not to over-compress the spring, as this could damage it.
4. Reassemble the oil pump.

Important Note: This modification is relatively simple, but it can be difficult to get the spring tension just right. Start with a small adjustment and test the oil flow before making further adjustments.

Safety First! Always wear eye protection and gloves when working with power tools. Be careful not to damage the oil pump components. If you are not comfortable with these modifications, it is best to leave them to a professional.

Case Study: DIY Oil Pump Modification

One time, I was working on a project where I needed to cut a large amount of hardwood timber. I was using my Stihl 064 with a 30-inch bar, and I was having trouble keeping the chain properly lubricated. I decided to try modifying the oil pump to increase the oil flow.

I started by enlarging the oil pump inlet and outlet ports using a Dremel tool. I was very careful not to remove too much material, and I smoothed the enlarged ports with sandpaper to remove any sharp edges.

Next, I modified the oil pump piston by grinding down the top of the piston to increase its stroke length. Again, I was very careful not to remove too much material, and I smoothed the modified piston with sandpaper.

Finally, I adjusted the oil pump spring tension by slightly compressing the spring in a vice.

After reassembling the oil pump, I tested the oil flow and found that it had increased significantly. I was now able to cut the hardwood timber without any problems.

Results:

Increased oil flow by approximately 50%.
Improved lubrication of the chain and bar.
Reduced chain and bar wear.
Successfully completed the hardwood timber project.

Choosing the Right Upgrade: A Balancing Act

The best upgrade for your Stihl 064 depends on your specific needs and budget.

H.O. Oil Pump: A reliable and effective upgrade for those who need increased oil flow but don’t want to risk damaging their saw with DIY modifications.
DIY Modifications: A cost-effective option for experienced mechanics who are comfortable working on chainsaws. However, it’s important to proceed with caution and understand the risks involved.

Before making any modifications, consider the following:

Bar Length: Longer bars require more oil.
Wood Type: Hardwoods require more oil than softwoods.
Cutting Conditions: Dusty or dirty conditions can increase the need for lubrication.
Your Mechanical Skills: Be honest about your abilities. If you’re not comfortable working on chainsaws, it’s best to leave the modifications to a professional.

Optimizing Chain and Bar Selection

Upgrading the oil pump is only part of the equation. The chain and bar you use also play a significant role in cutting performance.

Chain Selection: Matching the Chain to the Task

Choosing the right chain is crucial for efficient cutting. Here are some factors to consider:

Chain Pitch: The distance between the rivets on the chain. Common pitches for the Stihl 064 include .375″ (3/8″) and .404″.
Chain Gauge: The thickness of the drive links. Common gauges include .050″ and .063″.
Chain Type: Different chain types are designed for different applications.
- Full Chisel: Aggressive cutting, ideal for clean wood.
- Semi-Chisel: More durable than full chisel, suitable for dirty or frozen wood.
- Low-Kickback: Designed to reduce the risk of kickback, ideal for inexperienced users.

I generally prefer full chisel chains for their speed and efficiency, but I always switch to semi-chisel when cutting dirty or knotty wood.

Bar Selection: Length and Type

The bar length should be appropriate for the size of the wood you’re cutting. A bar that’s too long can be unwieldy and dangerous, while a bar that’s too short can limit your cutting capacity.

Bar Length: As mentioned earlier, the Stihl 064 can handle bars from 18″ to 30″.
Bar Type: Different bar types are designed for different applications.
- Solid Bar: Durable and long-lasting, ideal for heavy-duty use.
- Laminated Bar: Lighter and more flexible than solid bars, suitable for general use.
- Sprocket Nose Bar: Reduces friction and heat, improving cutting speed and chain life.

Chain and Bar Maintenance: A Key to Performance

Proper chain and bar maintenance is essential for optimal cutting performance and safety.

Chain Sharpening: Keep your chain sharp to ensure efficient cutting and reduce strain on the saw. Use a chain sharpener or file to maintain the correct cutting angles.
Bar Maintenance: Clean the bar regularly to remove sawdust and debris. Check the bar rails for wear and damage. Dress the bar rails with a file to remove any burrs or sharp edges.
Chain Tension: Maintain proper chain tension to prevent the chain from derailing or binding. The chain should be snug on the bar but still able to be pulled around by hand.
Lubrication: Ensure the chain and bar are properly lubricated to reduce friction and wear. Check the oil level regularly and refill as needed.

Fuel and Oil: The Lifeblood of Your Chainsaw

Using the correct fuel and oil is critical for the performance and longevity of your Stihl 064.

Fuel Requirements: Octane and Mix Ratio

The Stihl 064 requires a mixture of gasoline and two-stroke oil.

Gasoline: Use high-quality gasoline with a minimum octane rating of 89.
Two-Stroke Oil: Use Stihl-approved two-stroke oil or a high-quality synthetic two-stroke oil.
Mix Ratio: The recommended mix ratio is 50:1 (50 parts gasoline to 1 part oil).

I always use premium gasoline and Stihl Ultra two-stroke oil in my 064. It’s a bit more expensive, but it provides superior lubrication and protection.

Important Note: Always mix the fuel and oil in a separate container. Never mix directly in the fuel tank.

Oil Selection: Bar and Chain Oil

Using the correct bar and chain oil is essential for proper lubrication and reduced wear.

Viscosity: Choose a bar and chain oil with the correct viscosity for your climate and cutting conditions. Thicker oils are better for hot weather and heavy-duty cutting, while thinner oils are better for cold weather and light-duty cutting.
Additives: Look for bar and chain oils with additives that reduce friction, prevent rust, and protect against wear.
Biodegradability: Consider using a biodegradable bar and chain oil to minimize environmental impact.

I prefer to use a high-quality synthetic bar and chain oil with a viscosity that’s appropriate for my local climate.

Fuel and Oil Storage: Keeping it Fresh

Proper fuel and oil storage is essential for maintaining their quality and preventing contamination.

Fuel Storage: Store fuel in a clean, airtight container in a cool, dry place. Use a fuel stabilizer to prevent the fuel from degrading over time.
Oil Storage: Store bar and chain oil in a clean, airtight container in a cool, dry place.

Safety First: Protecting Yourself and Others

Chainsaw operation is inherently dangerous. Always prioritize safety and follow these guidelines:

Personal Protective Equipment (PPE)

Always wear appropriate PPE when operating a chainsaw.

Helmet: Protects your head from falling debris.
Eye Protection: Protects your eyes from flying debris.
Hearing Protection: Protects your ears from the loud noise of the chainsaw.
Gloves: Protect your hands from cuts and abrasions.
Chainsaw Chaps: Protect your legs from chainsaw cuts.
Steel-Toed Boots: Protect your feet from falling logs and chainsaw cuts.

I never operate a chainsaw without wearing all of the above PPE. It’s not worth the risk.

Safe Operating Practices

Follow these safe operating practices to minimize the risk of accidents.

Read the Manual: Familiarize yourself with the chainsaw’s operating instructions and safety precautions.
Inspect the Chainsaw: Before each use, inspect the chainsaw for any damage or defects.
Clear the Work Area: Remove any obstacles from the work area, such as rocks, branches, and people.
Maintain a Firm Grip: Always maintain a firm grip on the chainsaw with both hands.
Keep Your Balance: Maintain your balance and footing at all times.
Avoid Kickback: Be aware of the risk of kickback and take steps to avoid it.
Never Cut Above Shoulder Height: Cutting above shoulder height is dangerous and can lead to loss of control.
Never Cut with a Dull Chain: A dull chain is more likely to kick back and can be difficult to control.
Take Breaks: Take regular breaks to avoid fatigue.

Emergency Preparedness

Be prepared for emergencies.

First Aid Kit: Keep a well-stocked first aid kit on hand.
Communication: Have a way to communicate with others in case of an emergency.
Emergency Plan: Develop an emergency plan and share it with others.

Troubleshooting Common Issues

Even with proper maintenance and upgrades, you may encounter problems with your Stihl 064. Here are some common issues and their solutions:

Chainsaw Won’t Start

Possible Causes:
- Empty fuel tank
- Stale fuel
- Clogged fuel filter
- Dirty air filter
- Fouled spark plug
- Faulty ignition system
Troubleshooting Steps:
1. Check the fuel tank and refill if necessary.
2. Replace stale fuel with fresh fuel.
3. Clean or replace the fuel filter.
4. Clean or replace the air filter.
5. Clean or replace the spark plug.
6. Check the ignition system for proper spark.

Chainsaw Runs Poorly

Possible Causes:
- Dirty air filter
- Fouled spark plug
- Incorrect carburetor settings
- Clogged fuel filter
- Worn piston rings
Troubleshooting Steps:
1. Clean or replace the air filter.
2. Clean or replace the spark plug.
3. Adjust the carburetor settings.
4. Clean or replace the fuel filter.
5. Check the piston rings for wear.

Chain Not Oiling Properly

Possible Causes:
- Empty oil tank
- Clogged oil filter
- Clogged oil passages
- Faulty oil pump
Troubleshooting Steps:
1. Check the oil tank and refill if necessary.
2. Clean or replace the oil filter.
3. Clean the oil passages.
4. Check the oil pump for proper operation.

Chainsaw Overheating

Possible Causes:
- Dirty air filter
- Incorrect fuel mixture
- Dull chain
- Insufficient oil flow
Troubleshooting Steps:
1. Clean or replace the air filter.
2. Ensure the fuel mixture is correct.
3. Sharpen the chain.
4. Check the oil flow and adjust as needed.

Conclusion: Mastering the Stihl 064

The Stihl 064 is a powerful and versatile chainsaw that can be a valuable asset for any woodworker or logger. By understanding its specifications, upgrading the oiling system, and following proper maintenance and safety practices, you can maximize its performance and longevity.

Remember, chainsaw operation is inherently dangerous. Always prioritize safety and follow the guidelines outlined in this guide. With the right knowledge and skills, you can safely and effectively use your Stihl 064 to tackle any wood-cutting task.

I hope this guide has been helpful. Now get out there and start cutting, but always remember to be safe and responsible!