Can you start a Stihl Farm Boss chainsaw easily? Yes, with the right steps and a little practice, starting your Stihl Farm Boss chainsaw can be a straightforward process. This guide will walk you through everything you need to know, from fuel and oil to the actual ignition. We’ll cover the entire Stihl Farm Boss starting procedure and even touch on the Stihl Farm Boss first start.
The Stihl Farm Boss is a powerful and reliable tool, often a go-to for landowners and professionals alike. Whether you’re tackling fallen trees, clearing brush, or preparing firewood, knowing how to start it correctly is crucial for safety and efficiency. We’ll delve into specifics like the Stihl MS391 startup (a popular Farm Boss model), ensuring you’re prepared.
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Getting Ready: Pre-Start Essentials
Before you even think about pulling the starter cord, a few essential checks and preparations are necessary. These steps are vital for the longevity of your chainsaw and your personal safety.
Safety First: Paramount Stihl Farm Boss Safety Precautions
Chain saws are powerful tools and demand respect. Ignoring safety can lead to serious injury. Always follow these Stihl Farm Boss safety precautions:
- Read the Manual: This might seem obvious, but the owner’s manual is your best friend. It contains specific information for your model.
- Wear Protective Gear: Always wear:
- A helmet with a face shield or safety glasses.
- Hearing protection (earmuffs or earplugs).
- Heavy-duty gloves.
- Chainsaw chaps or protective trousers.
- Steel-toed boots.
- Inspect the Chainsaw: Before each use, check for:
- Loose parts.
- Damaged handles or guards.
- A sharp, properly tensioned chain.
- A clean air filter.
- Choose a Safe Starting Location: Start the chainsaw on a flat, stable surface. Ensure no one else is nearby. Clear the area of flammable materials.
- Never Engage the Chain Brake Accidentally: Make sure the chain brake is disengaged before starting.
- Hold Firmly: Grip the chainsaw with both hands, keeping your body balanced.
Fueling Your Farm Boss: The Right Mix
The correct fuel mixture is critical for the engine’s performance and to prevent damage. Stihl 2-stroke engines require a specific blend of gasoline and oil.
Stihl Farm Boss Fuel Mixture Explained
- Type of Gasoline: Use fresh, unleaded gasoline with an octane rating of 89 or higher. Avoid E10 or higher ethanol blends if possible, as they can degrade fuel system components over time.
- Type of Oil: Always use a high-quality Stihl 2-stroke engine oil. These oils are specifically formulated for air-cooled 2-stroke engines and provide optimal lubrication and protection.
- Mixing Ratio: The standard Stihl Farm Boss fuel mixture is 50:1. This means:
- For every 5 liters (or 1 gallon) of gasoline, add 100 ml (or 2.6 ounces) of Stihl 2-stroke oil.
- Alternatively: For every 1 liter (or quart) of gasoline, add 20 ml (or 0.68 ounces) of Stihl 2-stroke oil.
Table 1: Stihl Farm Boss Fuel Mixture Ratios
| Gasoline Amount (Liters) | Gasoline Amount (Gallons) | Stihl 2-Stroke Oil (ml) | Stihl 2-Stroke Oil (oz) |
|---|---|---|---|
| 1 | 0.26 | 20 | 0.68 |
| 5 | 1.32 | 100 | 2.6 |
| 10 | 2.64 | 200 | 5.3 |
| 20 | 5.28 | 400 | 10.6 |
- Mixing Container: Always use a clean, approved fuel mixing container. Pour the gasoline in first, then add the oil. Close the container securely and shake it well to ensure thorough mixing. Do not mix fuel directly in the chainsaw’s fuel tank.
- Freshness: Only mix the amount of fuel you will use in the near future. Stored fuel mixtures can degrade and cause starting problems.
Oiling the Chain: Essential Lubrication
A properly lubricated chain is vital for cutting efficiency and preventing premature wear on both the chain and the guide bar.
Stihl Farm Boss Oiling Chain Procedure
- Chain Oil Type: Use only Stihl-specific chain and bar oil or other high-quality bar and chain lubricants. Regular motor oil is not suitable and can clog the oiler.
- Fill the Oil Tank: Locate the oil tank cap (usually orange). Unscrew it and fill the tank with chain oil. Do not overfill.
- Check the Oil Level: Many Stihl chainsaws have a translucent oil tank, allowing you to see the oil level. Regularly check this level.
- Automatic Oiling: The Farm Boss has an automatic oiling system that lubricates the chain as you cut. You’ll know it’s working if you see a fine spray of oil coming off the chain when the engine is running.
The Starting Sequence: Step-by-Step Ignition
Now that your saw is fueled and oiled, it’s time to start it. This sequence is designed to prime the engine and engage the ignition system correctly. This is where we’ll focus on the Stihl Farm Boss starting procedure.
Step 1: Engage the Chain Brake
This is a crucial safety step. Push the chain brake lever forward firmly until it locks. This prevents the chain from spinning when the engine starts.
Step 2: Set the Choke
The choke enriches the fuel-air mixture, making it easier to start a cold engine.
- Cold Engine: For a cold engine, pull the choke lever up to the “choke” position.
- Warm Engine: If the engine is warm (recently shut off), you may not need the choke, or you might need it in a partially open position.
Step 3: Activate the Master Control Lever (M-Tronic or standard lever)
Your Stihl Farm Boss will have a master control lever that combines the choke, throttle lock, and on/off switch.
- Standard Lever: Move the lever to the “choke” position. This typically engages the full choke and the throttle lock.
- M-Tronic: If your model has M-Tronic, this electronic engine management system will automatically adjust the fuel mixture and timing. With M-Tronic, you typically just need to ensure the ignition is “on.”
Step 4: Prime the Engine (If Applicable)
Some Stihl Farm Boss models have a purging bulb or primer bulb.
- Locate the Primer Bulb: It’s a small, clear rubber bulb, usually near the carburetor.
- Press the Primer Bulb: Press it firmly several times (usually 3-5 times) until you see fuel filling the bulb. This pumps fuel into the carburetor, aiding starting. Not all models have a primer bulb.
Step 5: Activate the Decompression Valve (If Equipped)
Some larger Stihl saws, including certain Farm Boss models, have a decompression valve. This feature releases some of the compression in the cylinder, making the starter cord much easier to pull.
- Locate the Valve: It’s usually a small button near the starter housing.
- Press the Valve: Press and hold the decompression valve while pulling the starter cord. Release it after the first few pulls, or when the engine starts to fire.
Step 6: Engage the Throttle Lock (If Applicable)
Some older Farm Boss models might require you to engage the throttle lock, which partially opens the throttle when the choke is on. This is often done in conjunction with moving the master control lever.
Step 7: Pull the Starter Cord
- Secure Grip: Place the chainsaw firmly on the ground. Grip the starter handle with your dominant hand.
- Smooth Pull: Pull the starter cord out slowly until you feel resistance, then give it a sharp, firm pull.
- Multiple Pulls: You may need to pull the cord several times. Listen for the engine to “catch” or “fire” – this indicates it’s trying to start.
Step 8: Disengage the Choke (Once the Engine Fires)
Once the engine fires or “coughs” (makes a brief combustion sound), it means it has started to run.
- Move the Choke: Immediately push the choke lever back to the “run” or “no choke” position.
- Repeat Pull (If Necessary): If the engine doesn’t continue to run, you might need to pull the starter cord a few more times without the choke.
Step 9: Allow the Engine to Warm Up
Once the engine is running, let it idle for a few moments to warm up. Do not immediately rev the engine or engage the chain brake fully.
Step 10: Disengage the Chain Brake
When you’re ready to cut, firmly push the chain brake lever forward away from the front handle. The chain should be free to spin.
Starting a Warm Stihl Farm Boss
For a warm engine, the process is slightly different and generally easier.
- Ensure Chain Brake is Engaged.
- Set the Choke: Move the choke lever to the “run” or “no choke” position (if your model has a manual choke). If it has M-Tronic, the system handles this.
- Prime the Bulb (If Equipped): If your saw has a primer bulb, press it a few times.
- Pull the Starter Cord: Pull the cord firmly. The engine should start readily.
- Disengage Chain Brake: Once running, disengage the chain brake when ready to cut.
Special Considerations: Stihl MS391 Startup and First Start
Stihl MS391 Startup
The Stihl MS391 startup follows the general procedure outlined above. The MS391 is a popular model in the Farm Boss line, known for its power and durability. Key points for the MS391 include:
- Primer Bulb: The MS391 typically has a primer bulb. Use it to ensure fuel is in the carburetor.
- Choke Operation: Pay attention to the choke position based on whether the engine is cold or warm.
- Decompression Valve: The MS391 may also feature a decompression valve, making it easier to start.
Stihl Farm Boss First Start
The Stihl Farm Boss first start after purchase or long-term storage requires a bit more attention:
- Check All Connections: Ensure fuel lines, spark plug wire, and any other components are securely connected.
- Fuel Mixture: Use the correct fuel mixture as described earlier.
- Primer Bulb: Use the primer bulb as needed.
- Choke and Starter Cord: Follow the cold-start procedure. The engine might require a few more pulls than usual on its very first start.
- Break-in Period: New chainsaws often have a break-in period. Consult your manual for specific instructions, which may involve running the saw at varying speeds without heavy load for the first few tanks of fuel.
Stihl Farm Boss Troubleshooting: When It Won’t Start
If your Stihl Farm Boss refuses to start, don’t panic. Most starting issues can be resolved with some basic troubleshooting.
Common Starting Problems and Solutions
| Problem | Possible Cause | Solution |
|---|---|---|
| Engine won’t fire at all. | No fuel. | Check fuel tank level. Ensure the fuel filter isn’t clogged. Check fuel lines for blockages. |
| Spark plug issue. | Remove spark plug, check for spark (ground against engine block and pull starter). Clean or replace spark plug if fouled or damaged. Ensure plug gap is correct. | |
| Ignition system failure. | Check the Stihl Farm Boss ignition coil connection. If it appears damaged or disconnected, it may need replacement. | |
| Master control lever in wrong position. | Ensure the choke is set correctly for a cold start if applicable. | |
| Engine starts but dies immediately. | Choke needs adjustment. | If you just got a firing, push the choke to the “run” position. The engine may need more air. |
| Fuel/air mixture is too lean. | The Stihl Farm Boss carburetor adjustment might be needed, or the carburetor could be clogged. | |
| Loose spark plug wire. | Ensure the spark plug wire is firmly attached to the spark plug. | |
| Engine starts but runs rough or sputters. | Dirty air filter. | Clean or replace the air filter. A clogged filter restricts airflow. |
| Water in fuel. | Drain the fuel tank and carburetor, refill with fresh, properly mixed fuel. | |
| Incorrect fuel mixture. | Ensure you are using the correct 50:1 ratio and high-quality oil. | |
| Stihl Farm Boss carburetor adjustment required. | The carburetor might need adjustment. Incorrectly set idle or main jets can cause rough running. Caution: Carburetor adjustments should be done carefully. If unsure, consult a service manual or professional. | |
| Clogged fuel filter or fuel lines. | Check and clean or replace the fuel filter and check fuel lines for obstructions. | |
| Spark plug is fouled or worn. | Clean or replace the spark plug. | |
| Engine floods easily. | Too much priming or choke use. | If the engine is flooded, remove the spark plug, dry it, and let the engine air out for a few minutes. Then try starting without choke and without priming. |
| Starter rope is hard to pull. | Decompression valve not working (if equipped). | Ensure the decompression valve is engaged (pressed) before pulling. If it’s stuck, it may need servicing. |
| Cylinder damage or seized engine. | This is a more serious issue, often requiring professional repair. |
Stihl Farm Boss Carburetor Adjustment
The Stihl Farm Boss carburetor adjustment can affect how your saw starts and runs. Carburetors have adjustment screws that control the fuel-air mixture at idle and at higher speeds.
- Idle Speed Screw: Adjusts the engine speed when the throttle trigger is not pressed.
- Mixture Screws (L & H): These control the fuel mixture at low and high speeds, respectively.
Important: Carburetor adjustments are sensitive and can cause engine damage if done incorrectly. If you are not comfortable making these adjustments, it is best to have a qualified service center do it. Always follow the specific instructions for your model in the owner’s manual regarding carburetor adjustment. Generally, you’ll adjust the idle screw first, then the mixture screws to achieve smooth running and proper acceleration.
Stihl Farm Boss Ignition Coil Issues
The Stihl Farm Boss ignition coil is responsible for generating the spark that ignites the fuel. If the ignition coil fails, the saw will not start. Signs of a failing ignition coil include a weak or non-existent spark, or intermittent misfiring. If you suspect an ignition coil problem, it’s usually best to have it inspected and replaced by a professional.
Stihl Farm Boss Maintenance: Keeping It Running Smoothly
Regular Stihl Farm Boss maintenance is key to ensuring it starts easily and operates efficiently for years to come.
Routine Maintenance Tasks
- Air Filter Cleaning: Clean the air filter regularly, especially in dusty conditions. A clogged filter will hinder performance and make starting difficult.
- Spark Plug: Inspect the spark plug at least once a season. Clean it or replace it if it looks fouled or worn.
- Chain Sharpening and Tensioning: A sharp chain cuts more efficiently and reduces strain on the engine. Ensure the chain is always properly tensioned.
- Guide Bar: Keep the guide bar clean and free of debris. Ensure the oiling groove is clear.
- Fuel System: Use fresh fuel and clean the fuel filter periodically.
- Cooling Fins: Keep the engine’s cooling fins clean to prevent overheating.
- General Cleaning: After each use, clean dirt and debris from the saw.
Frequently Asked Questions (FAQ)
Q1: How much fuel mixture do I need for my Stihl Farm Boss?
A: The standard Stihl Farm Boss fuel mixture is 50:1. This means 50 parts gasoline to 1 part high-quality 2-stroke engine oil. Always use a quality oil specifically designed for 2-stroke engines.
Q2: Why is my Stihl Farm Boss hard to pull start?
A: Several factors can make it hard to pull start. It could be the chain brake being engaged, a cold engine requiring the choke, or an issue with the decompression valve if your model has one. If it’s consistently hard to pull even with the decompression valve engaged, there might be an internal engine problem.
Q3: Can I use regular gasoline in my Stihl Farm Boss?
A: You should use fresh, unleaded gasoline with an octane rating of 89 or higher. Avoid fuels with high ethanol content (E10 or higher) if possible, as they can degrade fuel system components. Always mix it with the correct 2-stroke oil.
Q4: What should I do if my Stihl Farm Boss won’t start after I’ve tried all the steps?
A: If you’ve followed the Stihl Farm Boss starting procedure carefully and it still won’t start, check the spark plug for spark and ensure the fuel is fresh and correctly mixed. If these basic checks don’t resolve the issue, there might be a problem with the carburetor, ignition system (like the Stihl Farm Boss ignition coil), or a blocked fuel line. It’s advisable to take it to a qualified Stihl dealer or service center for inspection and repair.
Q5: How often should I check the Stihl Farm Boss oiling chain system?
A: You should check that the chain oil reservoir is full before each use. You can also check that the oiler is working by observing if a fine spray of oil is being thrown off the chain when the engine is running at a moderate speed.
By following these detailed steps and embracing regular Stihl Farm Boss maintenance, you can confidently start your chainsaw every time and ensure it performs at its best. Remember that safety is paramount, so always prioritize your protective gear and a safe working environment.