Stihl 390 Specifications Explained (5 Pro Tips for Woodcutters)

Stihl MS 390 Specifications Explained: Plus 5 Pro Tips for Woodcutters and a Deep Dive into Firewood Cost Management

Have you ever wondered what truly separates a good chainsaw from a great one? Or how understanding your chainsaw’s specifications can save you money, time, and a whole lot of backache? Let’s be honest, choosing the right chainsaw isn’t just about brand loyalty; it’s about understanding your needs, the job at hand, and the machine’s capabilities. Today, we’re diving deep into the Stihl MS 390, a workhorse of a chainsaw, and I’ll share some pro tips gleaned from years of experience in the woodcutting world. But that’s not all. We’ll also explore the often-overlooked world of firewood preparation costs, helping you budget wisely and avoid those hidden expenses that can quickly turn a weekend project into a financial burden. So, grab your gloves, sharpen your chain (figuratively speaking, for now!), and let’s get started.

Understanding the Stihl MS 390 Specifications

The Stihl MS 390 is a mid-range chainsaw that’s been a favorite among homeowners and professionals alike for its robust performance and reliability. But what do those technical specifications actually mean in the real world? Let’s break them down:

Engine and Power

• Engine Displacement: Typically around 64.1 cc (3.9 cu. in.). This is the volume of the cylinder, directly related to the power the engine can generate. A larger displacement generally means more power for cutting through tougher wood.
• Engine Power: Around 3.1 kW (4.2 bhp). This figure tells you how much work the engine can do per unit of time. A higher horsepower rating translates to faster cutting speeds and the ability to handle larger logs.
• Engine Type: Two-stroke. This means the engine completes a power cycle in two strokes of the piston, making it more powerful and simpler than a four-stroke engine, but also requiring a fuel mixture of gasoline and oil.

What this means for you: The MS 390’s engine provides a good balance of power and weight, making it suitable for felling medium-sized trees, bucking firewood, and general property maintenance.

Weight and Dimensions

• Weight (without fuel and bar): Approximately 6.4 kg (14.1 lbs). Weight is a crucial factor, especially for extended use. A lighter saw reduces fatigue and improves maneuverability.
• Guide Bar Length: Typically ranges from 16 to 25 inches. The appropriate bar length depends on the size of the wood you’ll be cutting. A longer bar allows you to fell larger trees in a single pass, but it also adds weight and requires more power.

What this means for you: The MS 390’s weight is manageable for most users, but it’s still substantial enough to provide stability during cutting. Choose the right bar length for your common tasks to optimize performance and reduce strain.

Fuel and Oil

• Fuel Tank Capacity: Around 0.68 liters (23 oz). This determines how long you can run the saw before needing to refuel.
• Oil Tank Capacity: Around 0.35 liters (11.8 oz). The bar oil keeps the chain lubricated, reducing friction and extending its lifespan.
• Fuel Mixture: Typically 50:1 (gasoline to two-stroke oil). Using the correct fuel mixture is critical for engine longevity. Stihl recommends their own brand of two-stroke oil, but other high-quality oils meeting the API TC standard are also acceptable.

What this means for you: Always use the correct fuel mixture and high-quality bar oil. Skimping on these can lead to engine damage and costly repairs. Regularly check and refill both tanks to ensure smooth operation.

Cutting Attachments

• Chain Pitch: Usually .325 inch or 3/8 inch. The pitch is the distance between three consecutive rivets on the chain, divided by two. The pitch determines the type of wood the chain is best suited for and its cutting speed.
• Chain Gauge: Typically .063 inch (1.6 mm). The gauge is the thickness of the drive links that fit into the guide bar groove. Using the correct gauge is essential for proper chain fit and function.

What this means for you: Choosing the right chain pitch and gauge is crucial for efficient cutting. A .325-inch pitch is generally good for smaller to medium-sized wood, while a 3/8-inch pitch is better for larger, tougher wood. Always use a chain that matches your guide bar’s specifications.

5 Pro Tips for Woodcutters Using the Stihl MS 390

Now that we’ve covered the specs, let’s move on to some practical tips I’ve learned over the years.

1. Master the Art of Chain Sharpening: A dull chain is not only inefficient but also dangerous. It requires more force to cut, increasing the risk of kickback and operator fatigue. Invest in a good chain sharpening kit and learn how to sharpen your chain properly. I prefer using a file guide to maintain the correct angle and depth. Remember, a sharp chain will effortlessly pull itself into the wood.
2. Proper Fuel and Oil Maintenance is Key: As I mentioned earlier, using the correct fuel mixture is paramount. I always pre-mix my fuel in a separate container to ensure the correct ratio. Also, don’t let fuel sit in the tank for extended periods, especially during the off-season. Fuel can degrade and gum up the carburetor, leading to starting problems. Drain the tank and run the saw until it stalls to clear the fuel lines.
3. Regularly Clean the Air Filter: A clogged air filter restricts airflow to the engine, reducing power and increasing fuel consumption. Clean the air filter after every few uses, depending on the conditions. I use compressed air to blow out the debris, but you can also wash it with soap and water. Make sure it’s completely dry before reinstalling it.
4. Inspect and Maintain the Guide Bar: The guide bar is often overlooked, but it’s a critical component of the chainsaw. Regularly check the bar for wear and tear, such as burrs or uneven wear. Use a bar dresser to remove burrs and restore the bar’s shape. Also, make sure the oiler is functioning properly and lubricating the chain adequately.
5. Prioritize Safety Gear: This might seem obvious, but I can’t stress it enough. Always wear appropriate safety gear, including a helmet with a face shield, hearing protection, gloves, and chainsaw chaps. These simple precautions can prevent serious injuries. I’ve seen too many accidents that could have been avoided with proper safety gear.

The Hidden Costs of Firewood Preparation: A Budgeting Guide

Now, let’s shift our focus to the often-underestimated costs associated with preparing firewood. Many people think that cutting their own firewood is a cheap way to heat their homes, but they often overlook the various expenses involved. Let’s break down these costs and explore some strategies for managing your firewood budget. I once underestimated the cost of a firewood project, thinking I could get away with a weekend’s work and a few gallons of gas. Boy, was I wrong! The hidden expenses quickly added up, and I ended up spending far more than I had anticipated.

1. Timber Acquisition Costs: Free Isn’t Always Free

The first cost to consider is the timber itself. You might think you’re getting free wood if you’re harvesting it from your own property or obtaining it from a friend or neighbor. However, even “free” wood has a cost.

• Your Own Property: Even if you own the land, there’s an opportunity cost to consider. You could be using that land for other purposes, such as farming or recreation. Also, you’ll need to factor in the time and effort required to fell the trees, which could be spent on other income-generating activities.
• Permits and Regulations: In some areas, you may need a permit to harvest timber, even on your own property. These permits can cost anywhere from a few dollars to several hundred dollars, depending on the location and the amount of timber you’re harvesting.
• “Free” Wood from Others: If you’re getting wood from someone else, make sure you have a clear agreement on the terms. Who’s responsible for felling the trees? Who’s responsible for hauling the wood? Are there any restrictions on the type of wood you can take? A verbal agreement isn’t enough; get it in writing to avoid misunderstandings.

Data Point: According to the USDA Forest Service, the average stumpage price (the price paid for standing timber) varies widely depending on the species, quality, and location. In some regions, stumpage prices for hardwood can range from \$20 to \$100 per cord, while softwood prices can be even higher.

2. You’ll also need to consider:

• Chainsaw Maintenance: Chainsaws require regular maintenance, including chain sharpening, air filter cleaning, spark plug replacement, and carburetor adjustments. These costs can add up over time. A new chain can cost between \$20 and \$50, depending on the size and type. A sharpening kit can cost between \$30 and \$100.
• Splitting Tools: If you’re splitting wood by hand, you’ll need a maul, wedges, and a sledgehammer. A good quality maul can cost between \$50 and \$100. Wedges can cost between \$10 and \$30 each.
• Log Splitter: If you’re processing a lot of firewood, a log splitter can save you a lot of time and effort. Log splitters can range in price from a few hundred dollars for a small electric model to several thousand dollars for a large gas-powered model. Renting a log splitter is also an option, typically costing around \$50 to \$100 per day.
• Hauling Equipment: You’ll need a way to transport the wood from the forest to your woodpile. This could involve a pickup truck, a trailer, or even a wheelbarrow. The cost of hauling equipment can vary widely depending on your needs.
• Safety Gear: As I mentioned earlier, safety gear is essential. A helmet with a face shield can cost between \$50 and \$100. Hearing protection can cost between \$20 and \$50. Chainsaw chaps can cost between \$100 and \$200.

Case Study: I know a fellow who thought he’d save money by buying a cheap, off-brand chainsaw. Within a year, it had broken down twice, requiring costly repairs. He ended up spending more on repairs than he would have if he had bought a quality chainsaw in the first place.

3. Labor Costs: Your Time is Money

Even if you’re doing all the work yourself, your time has value. Consider how much you could be earning if you were spending that time on other activities.

• Felling Trees: Felling trees can be a dangerous and time-consuming task. Depending on the size and complexity of the job, it could take several hours or even days to fell a single tree.
• Bucking and Splitting: Bucking the logs into firewood-sized pieces and splitting them can also be a time-consuming process. A cord of wood can take anywhere from 4 to 8 hours to split by hand, depending on the type of wood and your physical condition.
• Stacking and Drying: Stacking the wood in a well-ventilated area to dry is also important. Properly drying firewood can take several months or even a year.
• Hiring Help: If you’re not able to do all the work yourself, you’ll need to hire help. Labor costs can vary widely depending on the location and the skill level of the workers. Expect to pay anywhere from \$15 to \$30 per hour for manual labor.

Industry Benchmark: According to data from various sources, the average cost to have a cord of firewood delivered and stacked ranges from \$200 to \$400, depending on the location, the type of wood, and the quantity purchased. This gives you a benchmark to compare against your own labor costs.

4. Fuel and Transportation Costs: The Miles Add Up

Don’t forget to factor in the cost of fuel for your chainsaw, log splitter, and hauling equipment.

• Chainsaw Fuel: Chainsaws consume a significant amount of fuel, especially when cutting large trees. A typical chainsaw can burn through a gallon of fuel in a few hours of heavy use.
• Log Splitter Fuel: Gas-powered log splitters also consume fuel. The amount of fuel consumed will depend on the size and type of log splitter.
• Transportation Costs: Hauling wood can be expensive, especially if you’re driving a long distance. Factor in the cost of gasoline, vehicle maintenance, and any tolls or parking fees.

Calculation Example: Let’s say you need to haul 5 cords of wood 50 miles round trip. Your truck gets 15 miles per gallon, and gasoline costs \$3.50 per gallon. The fuel cost would be (50 miles / 15 mpg) * \$3.50/gallon = \$11.67 per trip. For 5 cords, the total fuel cost would be \$11.67 * 5 = \$58.35.

5. Drying Time and Storage: Patience Pays Off

Properly drying firewood is essential for efficient burning and reducing creosote buildup in your chimney.

• Drying Time: Firewood needs to dry for at least six months, and preferably a year, before it’s burned. The drying time will depend on the type of wood, the climate, and the way the wood is stacked.
• Storage Space: You’ll need a dry, well-ventilated place to store your firewood. This could be a woodshed, a tarp-covered stack, or even a garage.
• Moisture Content: The ideal moisture content for firewood is below 20%. You can use a moisture meter to check the moisture content of your wood. Moisture meters typically cost between \$20 and \$50.

Formula for Estimating Drying Time: Drying time is affected by wood species, initial moisture content, air temperature, and relative humidity. While a precise formula is complex, a general rule of thumb is that hardwood firewood, properly stacked, will lose approximately 1% of moisture content per week during the drying season (spring and summer). Therefore, reducing moisture from 50% to 20% would take approximately 30 weeks.

Cost Optimization and Budget Management: Smart Choices for Firewood

Now that we’ve explored the various costs associated with firewood preparation, let’s look at some strategies for optimizing your budget and reducing expenses.

• Choose the Right Wood Species: Different wood species have different heating values and drying times. Hardwoods like oak, maple, and beech have higher heating values than softwoods like pine and fir. However, softwoods are easier to split and dry faster. Consider your needs and resources when choosing a wood species.
• Buy in Bulk: Buying firewood in bulk can often save you money. Many firewood suppliers offer discounts for large orders.
• Season Your Wood Properly: Properly seasoning your wood can significantly improve its burning efficiency and reduce creosote buildup. Stack your wood in a well-ventilated area and allow it to dry for at least six months.
• Maintain Your Equipment: Regular maintenance of your chainsaw, log splitter, and other equipment can prevent costly repairs and extend their lifespan.
• Consider Alternative Fuel Sources: If firewood is too expensive or time-consuming to prepare, consider alternative fuel sources such as wood pellets, propane, or natural gas.

Table: Cost Comparison of Different Firewood Preparation Methods

This table provides a simplified comparison of the costs associated with different firewood preparation methods. The actual costs will vary depending on your specific circumstances.

Actionable Takeaways: Planning Your Next Firewood Project

So, what are the key takeaways from this deep dive into Stihl MS 390 specifications and firewood cost management?

• Understand Your Chainsaw: Knowing your chainsaw’s specifications is essential for safe and efficient operation.
• Prioritize Safety: Always wear appropriate safety gear when operating a chainsaw or preparing firewood.
• Budget Wisely: Carefully consider all the costs associated with firewood preparation, including timber acquisition, tool and equipment, labor, fuel, and drying time.
• Optimize Your Costs: Choose the right wood species, buy in bulk, season your wood properly, and maintain your equipment to reduce expenses.
• Plan Ahead: Start planning your firewood project well in advance to allow for proper drying time.

Next steps:

1. Assess your firewood needs for the upcoming heating season.
2. Estimate the costs associated with your chosen firewood preparation method.
3. Create a detailed budget and track your expenses.
4. Start gathering your firewood well in advance of the heating season.

By following these tips, you can enjoy the warmth and comfort of a wood-burning fire without breaking the bank. Remember, a little planning and preparation can go a long way in making your firewood project a success. Now, go forth and conquer those logs, but always prioritize safety and budget wisely. And remember, the best woodcutters are the ones who are both skilled and smart about their resources.

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