Chainsaw Starts Then Dies: Fix Stihl 046 Revs Issue (Expert Tips)

A chainsaw that starts and dies is a common problem, but the solutions can range from simple fixes to more complex repairs. The Stihl 046, known for its robust performance, is no exception. Let’s break down the potential causes and how to address them, all while keeping an eye on the potential costs involved.

Understanding the Root Cause: Why Your Stihl 046 Won’t Stay Running

The “starts then dies” issue often points to a problem with fuel, air, or ignition. A Stihl 046 that revs erratically before dying often adds another layer to the puzzle. Let’s explore the most common culprits:

1. Fuel System Woes

Contaminated Fuel: This is the most frequent offender. Old or contaminated fuel can clog the carburetor and fuel lines, preventing the engine from receiving a consistent fuel supply. I once spent an entire afternoon battling a Stihl 046 that refused to cooperate, only to discover a sediment-filled fuel tank.
- Cost Implication: Replacing fuel is cheap (a few dollars per gallon), but neglecting this can lead to costly carburetor damage (potentially $50-$150 for a new carb).
Clogged Fuel Filter: The fuel filter prevents debris from entering the carburetor. A clogged filter restricts fuel flow, leading to stalling.
- Cost Implication: Fuel filters are inexpensive (around $5-$10), and replacing them is a simple DIY task.
Faulty Fuel Lines: Cracked or deteriorated fuel lines can leak air, disrupting the fuel-air mixture.
- Cost Implication: Replacing fuel lines is relatively affordable (around $10-$20), but requires some mechanical aptitude.
Carburetor Issues: The carburetor mixes fuel and air. Dirt, varnish, or mechanical problems can cause it to malfunction. This is where the “revs” part of the problem often originates.
- Cost Implication: Carburetor cleaning can be done with carburetor cleaner (around $10), but a rebuild kit costs $20-$40. A new carburetor can set you back $50-$150.

2. Air Intake Problems

Dirty Air Filter: A clogged air filter restricts airflow, leading to a rich fuel mixture and stalling.
- Cost Implication: Air filters are cheap (around $5-$15), and regular cleaning or replacement is crucial.
Obstructed Air Intake: Debris blocking the air intake can also starve the engine of air.
- Cost Implication: Clearing debris is free, but neglecting this can lead to engine overheating and damage.

3. Ignition System Failures

Faulty Spark Plug: A damaged or fouled spark plug can prevent the engine from firing consistently.
- Cost Implication: Spark plugs are inexpensive (around $5-$10), and replacing them is a basic maintenance task.
Weak Ignition Coil: The ignition coil generates the high-voltage spark needed to ignite the fuel-air mixture. A weak coil can cause intermittent starting and stalling.
- Cost Implication: Ignition coils can be pricey, ranging from $30-$80.
Flywheel Key Shear: The flywheel key aligns the flywheel with the crankshaft. If sheared, the timing will be off, leading to starting problems.
- Cost Implication: Flywheel keys are cheap (a few dollars), but replacing them requires removing the flywheel, which can be challenging.

4. Exhaust Issues

Clogged Spark Arrestor: The spark arrestor prevents sparks from exiting the exhaust. A clogged arrestor restricts exhaust flow, leading to overheating and stalling.
- Cost Implication: Cleaning the spark arrestor is free, and replacement arrestors are inexpensive (around $5-$10).
Restricted Exhaust Port: Carbon buildup in the exhaust port can also restrict exhaust flow.
- Cost Implication: Cleaning the exhaust port requires removing the muffler and using a scraper or solvent.

5. Mechanical Problems

Piston/Cylinder Damage: Scratches or scoring on the piston or cylinder walls can reduce compression, making the engine difficult to start and keep running. This is often a result of running the saw with incorrect fuel mixture or insufficient oil.
- Cost Implication: This is a major repair, potentially requiring a new piston and cylinder kit (around $100-$300) and significant labor.
Crankshaft Seal Leak: Leaking crankshaft seals can allow air to enter the engine, disrupting the fuel-air mixture.
- Cost Implication: Replacing crankshaft seals requires splitting the engine case, a complex repair best left to professionals. Expect to pay $150-$400.

Diagnosing the Problem: A Step-by-Step Approach

Before diving into repairs, it’s crucial to accurately diagnose the cause of the problem. Here’s a systematic approach I use:

Fresh Fuel Check: Start with the simplest solution. Drain the old fuel and replace it with fresh, properly mixed fuel (usually a 50:1 ratio of gasoline to 2-stroke oil for the Stihl 046).
Air Filter Inspection: Remove the air filter and examine it for dirt and debris. Clean or replace as needed.
Spark Plug Examination: Remove the spark plug and inspect it. Look for signs of fouling (carbon buildup) or damage. Clean or replace as needed. Check the spark by grounding the plug against the engine and pulling the starter cord. You should see a strong, consistent spark.
Fuel Filter Check: Access the fuel filter inside the fuel tank. If it’s clogged or dirty, replace it.
Fuel Line Inspection: Examine the fuel lines for cracks or leaks. Replace if necessary.
Carburetor Adjustment: The Stihl 046 carburetor has adjustment screws for low (L) and high (H) speed settings. Incorrect settings can cause starting and stalling problems. Consult your owner’s manual for the proper adjustment procedure. Note: Carburetor adjustment can be tricky. If you’re not comfortable with it, seek professional help.
Compression Test: A compression test can reveal problems with the piston, cylinder, or rings. A healthy Stihl 046 should have a compression reading of at least 120 PSI. A compression tester costs around $30-$50.
Leak Down Test: This test can pinpoint leaks in the cylinder, valves, or head gasket. This is more involved and generally requires specialized tools and knowledge.

Fixing the Problem: DIY vs. Professional Repair

Once you’ve identified the cause of the problem, you’ll need to decide whether to tackle the repair yourself or take it to a professional.

DIY Repairs: When to Roll Up Your Sleeves

DIY repairs can save you money, but they require mechanical aptitude, the right tools, and a willingness to learn. Here are some repairs that are generally suitable for DIYers:

Fuel System Cleaning: Cleaning the fuel tank, fuel lines, and carburetor is a relatively straightforward task.
Fuel Filter Replacement: This is a simple and inexpensive repair.
Air Filter Replacement: Another easy and inexpensive repair.
Spark Plug Replacement: A basic maintenance task.
Carburetor Rebuild: This is more involved than cleaning, but rebuild kits are available, and there are numerous online tutorials to guide you.
Spark Arrestor Cleaning: Easy and free.
Fuel Line Replacement: Relatively easy, but requires some dexterity.

Tools Needed for DIY Repairs:

Screwdrivers (Phillips and flathead)
Pliers
Wrenches
Socket set
Spark plug wrench
Carburetor cleaner
Fuel filter removal tool (optional)
Compression tester (optional)
Multimeter (for testing ignition coil, optional)

Cost of DIY Repairs:

The cost of DIY repairs will vary depending on the parts needed. However, you can generally save a significant amount of money compared to professional repair costs.

Professional Repairs: When to Call in the Experts

Some repairs are best left to professionals. These include:

Engine Rebuilds: Repairs involving the piston, cylinder, crankshaft, or crankshaft seals require specialized tools and knowledge.
Complex Carburetor Issues: If you’re unable to diagnose or fix carburetor problems after cleaning and rebuilding, it’s best to seek professional help.
Electrical Issues: Diagnosing and repairing electrical problems can be challenging, especially if you’re not familiar with electrical systems.
Any Repair You’re Not Comfortable With: It’s always better to err on the side of caution. If you’re not confident in your ability to perform a repair safely and correctly, take it to a professional.

Cost of Professional Repairs:

Professional chainsaw repair costs can vary widely depending on the repair shop, the complexity of the repair, and the cost of parts. Expect to pay anywhere from $50 to $500 or more for professional chainsaw repair. I’ve seen simple carburetor cleanings cost around $80, while engine rebuilds can easily exceed $400.

Factors Affecting Professional Repair Costs:

Labor Rate: Repair shops typically charge an hourly labor rate, which can range from $50 to $100 or more.
Parts Costs: The cost of replacement parts can vary depending on the brand, model, and availability.
Diagnostic Fee: Some repair shops charge a diagnostic fee to determine the cause of the problem. This fee is often waived if you proceed with the repair.
Location: Repair costs can vary depending on your geographic location.

Example Cost Breakdown (Professional Repair):

Let’s say your Stihl 046 needs a new carburetor and a spark plug replacement.

Labor (2 hours at $75/hour): $150
Carburetor: $80
Spark Plug: $10
Total Cost: $240

Budgeting for Chainsaw Maintenance and Repairs

Chainsaw maintenance is an ongoing expense. Proper maintenance can extend the life of your chainsaw and prevent costly repairs down the road. Here’s how I budget for chainsaw maintenance:

1. Routine Maintenance Budget:

Fuel and Oil: Estimate your annual fuel and oil consumption based on your usage. A good rule of thumb is to budget around $50-$100 per year for fuel and oil for a homeowner using a chainsaw for occasional firewood cutting or storm cleanup. For professional loggers, this figure can easily climb to several hundred dollars or more.
Air Filters: Budget for replacing the air filter every year or two. A pack of air filters costs around $20-$30.
Spark Plugs: Replace the spark plug every year. A pack of spark plugs costs around $10-$20.
Bar Oil: This is crucial for chain lubrication. Budget around $30-$50 per year for bar oil.
Chain Sharpening: You can sharpen your own chain with a file (around $20 for a file kit) or take it to a professional. Professional chain sharpening typically costs around $10-$20 per chain. I prefer to sharpen my own chains, as it allows me to maintain the chain’s sharpness more frequently.

2. Repair Fund:

Set aside a dedicated repair fund to cover unexpected repairs. A good starting point is to budget around 5-10% of the chainsaw’s purchase price per year. For a Stihl 046, which might cost around $800-$1000 used, this translates to $40-$100 per year.

3. Tool Replacement Fund:

Chainsaws don’t last forever. Eventually, they’ll need to be replaced. Start saving for a replacement chainsaw so you’re not caught off guard when your current saw gives up the ghost.

4. Tracking Expenses:

Keep track of all your chainsaw-related expenses. This will help you refine your budget and identify areas where you can save money. I use a simple spreadsheet to track my expenses, but there are also numerous budgeting apps available.

Example Annual Chainsaw Budget:

Fuel and Oil: $75
Air Filters: $15
Spark Plugs: $10
Bar Oil: $40
Chain Sharpening (DIY): $20 (file kit)
Repair Fund: $75 (7.5% of $1000 purchase price)
Total Annual Budget: $235

Cost-Saving Tips for Chainsaw Maintenance

Here are some tips to help you save money on chainsaw maintenance and repairs:

Use Fresh Fuel: Always use fresh, properly mixed fuel. This will prevent carburetor problems and extend the life of your engine.
Clean Air Filter Regularly: A clean air filter ensures proper airflow and prevents engine damage.
Sharpen Your Chain Regularly: A sharp chain cuts more efficiently and reduces strain on the engine.
Lubricate Your Chain Properly: Use high-quality bar oil to keep your chain lubricated and prevent wear.
Store Your Chainsaw Properly: Store your chainsaw in a clean, dry place to prevent rust and corrosion.
Perform Regular Maintenance: Follow the manufacturer’s recommended maintenance schedule.
Learn Basic Repair Skills: Learning how to perform basic repairs can save you money on professional repair costs.
Shop Around for Parts: Compare prices from different suppliers before buying replacement parts.
Consider Used Parts: Used parts can be a more affordable option for some repairs. However, be sure to inspect used parts carefully before buying them.
Buy in Bulk: Buying fuel, oil, and other supplies in bulk can save you money in the long run.
Negotiate with Repair Shops: Don’t be afraid to negotiate with repair shops. Get multiple quotes and ask if they offer any discounts.

Case Study: My Stihl 046 Carburetor Conundrum

I remember one particularly frustrating experience with my own Stihl 046. It started fine but would die as soon as I gave it any throttle. I meticulously went through the usual suspects: fuel, air filter, spark plug. All seemed fine. I even cleaned the carburetor, but the problem persisted.

Finally, after hours of troubleshooting, I discovered a tiny crack in the fuel line inside the fuel tank. The crack was so small that it was difficult to see, but it was enough to allow air to enter the fuel line, disrupting the fuel-air mixture. A $15 fuel line replacement solved the problem. This experience taught me the importance of thoroughly inspecting all components of the fuel system, even the ones that seem insignificant.

Understanding Timber Prices and Fuelwood Market Rates

Beyond the chainsaw itself, the cost of acquiring wood – whether for logging or firewood – is a significant factor. Timber prices fluctuate based on species, quality, location, and market demand.

Timber Prices:

Global Trends: Global timber prices are influenced by factors such as deforestation rates, sustainable forestry practices, and economic growth. Countries with abundant forests and sustainable forestry practices tend to have lower timber prices.
Regional Variations: Timber prices vary significantly by region. For example, softwood lumber prices in North America are often higher than in Scandinavia due to transportation costs and supply chain factors.
Species-Specific Pricing: Hardwoods like oak and maple command higher prices than softwoods like pine and fir due to their density, durability, and aesthetic appeal.
Data Points: According to the USDA Forest Service, the average stumpage price (the price paid to the landowner for standing timber) for sawtimber in the United States in 2022 was around $300 per thousand board feet (MBF). However, this figure can vary widely depending on the species and location.

Fuelwood Market Rates:

Price per Cord: Fuelwood is typically sold by the cord, which is a stacked pile of wood measuring 4 feet high, 4 feet wide, and 8 feet long, or 128 cubic feet.
Regional Differences: Fuelwood prices vary depending on location, wood species, and demand. In urban areas with limited firewood supplies, prices tend to be higher.
Seasonality: Fuelwood prices typically peak during the fall and winter months, when demand is highest.
Data Points: According to the U.S. Energy Information Administration (EIA), the average price of firewood in the United States in 2023 ranged from $200 to $400 per cord, depending on the region. However, prices can be significantly higher in some areas, particularly for seasoned hardwoods.

Calculating Volume of Logs and Estimating Drying Time

Accurately estimating the volume of logs is crucial for determining their value and planning your wood processing projects.

Log Volume Calculation:

Doyle Log Scale: The Doyle Log Scale is a common method for estimating the board foot volume of logs. The formula is: Board Feet = (Diameter in inches - 4)^2 * Length in feet / 16.
International 1/4-inch Log Scale: This scale is considered more accurate than the Doyle Log Scale, especially for smaller logs. It takes into account the taper of the log and the kerf (sawdust waste) produced during sawing.
Scribner Log Scale: The Scribner Log Scale is another widely used method. It is generally more conservative than the Doyle Log Scale.

Estimating Drying Time:

Wood Species: Hardwoods generally take longer to dry than softwoods.
Log Size: Larger logs take longer to dry than smaller logs.
Climate: Warm, dry climates are ideal for drying wood.
Air Circulation: Good air circulation is essential for removing moisture from the wood.
Stacking Method: Proper stacking methods, such as stickering (placing thin strips of wood between layers of logs), promote air circulation and even drying.
Rule of Thumb: As a general rule of thumb, it takes about one year per inch of thickness for wood to air dry. However, this can vary depending on the factors mentioned above.
Moisture Meter: A moisture meter can be used to accurately measure the moisture content of wood. Firewood should have a moisture content of less than 20% for optimal burning. Moisture meters cost around $20-$50.

Actionable Takeaways and Next Steps

Troubleshoot Systematically: When your chainsaw starts then dies, follow a systematic approach to diagnose the problem. Start with the simplest solutions and work your way up to more complex repairs.
Prioritize Maintenance: Regular chainsaw maintenance is essential for preventing costly repairs and extending the life of your saw.
Budget Wisely: Create a chainsaw maintenance budget to cover routine expenses and unexpected repairs.
Consider DIY Repairs: Learning basic repair skills can save you money on professional repair costs.
Know When to Call a Pro: Some repairs are best left to professionals. Don’t hesitate to seek professional help when needed.
Understand Timber and Fuelwood Markets: Research timber prices and fuelwood market rates in your area to make informed decisions about wood acquisition.
Calculate Log Volume Accurately: Use log scaling methods to estimate the volume of logs and determine their value.
Estimate Drying Time: Understand the factors that affect wood drying time and use proper stacking methods to promote even drying.
Invest in Quality Tools: Invest in quality tools and equipment to make your wood processing projects easier and more efficient.

Challenges Faced by Small-Scale Loggers and Firewood Suppliers

Small-scale loggers and firewood suppliers often face unique challenges in managing costs and staying competitive. These challenges include:

Limited Access to Capital: Small-scale operators often have difficulty securing financing for equipment purchases and upgrades.
Fluctuating Market Prices: Timber and fuelwood prices can fluctuate significantly, making it difficult to plan and budget.
Competition from Larger Operations: Larger logging and firewood companies often have economies of scale that allow them to offer lower prices.
Regulatory Compliance: Logging and firewood operations are subject to various regulations, which can be costly and time-consuming to comply with.
Labor Costs: Finding and retaining skilled labor can be a challenge, especially in rural areas.
Transportation Costs: Transporting logs and firewood can be expensive, especially over long distances.
Equipment Maintenance and Repair: Maintaining and repairing logging and firewood equipment can be costly.
Safety Concerns: Logging and firewood operations are inherently dangerous. Safety training and equipment are essential for preventing accidents.
Weather Dependence: Logging and firewood operations are heavily dependent on weather conditions. Inclement weather can disrupt operations and reduce productivity.

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Final Thoughts

Fixing a chainsaw that starts then dies, especially a Stihl 046 with revving issues, can seem daunting. But with a systematic approach, a little know-how, and a willingness to get your hands dirty, you can diagnose and fix the problem yourself. By understanding the cost implications of repairs and budgeting wisely for maintenance, you can keep your chainsaw running smoothly for years to come. And remember, whether you’re a seasoned logger or a weekend warrior, proper chainsaw maintenance is an investment in your safety, productivity, and peace of mind. So, grab your tools, put on your safety gear, and get ready to conquer that wood!

Chainsaw Starts Then Dies: Fix Stihl 046 Revs Issue (Expert Tips)