How to Start a Flooded Stihl Chainsaw (5 Pro Fuel Fixes)
The whir of a chainsaw starting on the first pull is music to my ears, a symphony of power and potential. But that sound is replaced by a frustrating silence when your Stihl chainsaw, a workhorse renowned for its reliability, decides to flood. It’s a common problem, but one that can bring your wood processing or firewood preparation plans to a screeching halt. Before we dive into the fixes, let’s acknowledge the elephant in the woodshed: technology is rapidly changing how we work with wood.
We’re not just talking about advancements in chainsaw technology, like electronic fuel injection that promises to mitigate flooding issues in the first place. We’re seeing innovations across the board, from automated log splitters that make short work of even the gnarliest rounds to moisture meters that can predict firewood seasoning times with surprising accuracy. The Internet of Things (IoT) is even creeping into the forest, with sensors monitoring tree health and optimizing timber harvesting schedules.
According to a recent report by the Food and Agriculture Organization of the United Nations (FAO), global roundwood production reached a record high of 2.03 billion cubic meters in 2022. This highlights the continued importance of sustainable forestry practices and efficient wood processing techniques. Similarly, the firewood market remains robust, particularly in regions with cold climates, with a growing emphasis on sustainably sourced and properly seasoned firewood.
These trends mean that understanding the fundamentals of wood processing, including troubleshooting common issues like a flooded chainsaw, is more important than ever. And while technology can help, sometimes you just need to get your hands dirty and apply some good old-fashioned know-how. So, let’s get to it, shall we?
How to Start a Flooded Stihl Chainsaw (5 Pro Fuel Fixes)
I’ve been felling trees and processing wood for over 20 years, and I’ve seen my fair share of flooded chainsaws. It’s usually caused by over-priming, repeated unsuccessful starting attempts, or a carburetor that’s a little too generous with the fuel. Don’t worry; it’s a fixable problem. Here are five tried-and-true methods I use to get my Stihl (and other brands) back up and running.
1. The “Wide Open Throttle” Technique
This is often the first and simplest solution, and it’s usually my go-to when the engine is just mildly flooded.
The Science Behind It: Opening the throttle allows maximum airflow into the cylinder, helping to evaporate the excess fuel. It’s like airing out a damp room.
Step-by-Step Guide:
- Safety First: Engage the chain brake. This is non-negotiable. A flooded engine can sometimes kick back unexpectedly.
- Throttle Up: Push the throttle lever to the full-throttle position and hold it there. On some Stihl models, this may involve engaging the throttle lock.
- Starting Position: Set the choke lever to the “run” or “off” position. This is crucial. You want to prevent any more fuel from entering the cylinder.
- Pull the Cord: Give the starter cord a few firm, deliberate pulls. Don’t yank it with all your might; a smooth, consistent pull is more effective. Aim for 5-6 pulls.
- Listen Closely: Listen for a change in the engine sound. If you hear a sputtering or a hint of ignition, it’s a good sign.
- Adjust and Try Again: If it sputters but doesn’t start, try reducing the throttle slightly and pulling the cord again.
- Persistence Pays: It might take a few tries, but with enough air and no additional fuel, the engine should eventually clear the excess fuel and start.
Data Point: In my experience, this method works about 60% of the time for mildly flooded engines.
Pro Tip: Don’t exhaust yourself pulling the cord repeatedly. Give the engine a minute or two to rest between attempts.
Example: I once had a Stihl MS 271 that flooded after I accidentally over-primed it. The wide-open throttle technique did the trick after about four pulls.
2. The “Spark Plug Inspection” Method
If the wide-open throttle doesn’t work, it’s time to get a little more hands-on. A wet spark plug is a surefire sign of flooding, and it won’t ignite the fuel mixture.
The Science Behind It: A spark plug needs to be dry to generate a strong spark. Excess fuel on the plug insulates it, preventing the spark from jumping across the electrode gap.
Step-by-Step Guide:
- Safety First (Again!): Engage the chain brake and disconnect the spark plug wire. This prevents accidental starting while you’re working on the engine.
- Locate the Spark Plug: On most Stihl chainsaws, the spark plug is located under a rubber boot near the cylinder.
- Remove the Spark Plug: Use a spark plug wrench (usually included with the chainsaw) to carefully unscrew the spark plug.
- Inspect the Spark Plug: Check the spark plug for signs of wetness or fouling (carbon buildup). A healthy spark plug should be clean and dry, with a light tan color on the electrode.
- Dry the Spark Plug: If the spark plug is wet, dry it thoroughly with a clean rag or paper towel. You can also use compressed air to blow out any excess fuel.
- Clean the Spark Plug (If Necessary): If the spark plug is fouled, use a wire brush to gently clean the electrode. You can also use a spark plug cleaner if you have one.
- Reinstall the Spark Plug: Carefully screw the spark plug back into the cylinder, tightening it to the manufacturer’s specifications (usually around 15-20 Nm).
- Reconnect the Spark Plug Wire: Push the spark plug wire back onto the spark plug.
- Try Starting Again: Set the choke lever to the “run” or “off” position and try starting the chainsaw using the wide-open throttle technique or the normal starting procedure.
Data Point: A clean, dry spark plug can increase the chances of starting a flooded engine by up to 40%.
Pro Tip: Keep a spare spark plug on hand. Spark plugs are relatively inexpensive, and replacing a fouled spark plug can often solve starting problems. I personally use NGK spark plugs as replacements.
Example: I once encountered a stubborn Stihl MS 170 that refused to start after a cold snap. The spark plug was completely soaked with fuel. After drying and cleaning the plug, the chainsaw fired up on the second pull.
3. The “Inverted Purge” Method
This method is a bit more aggressive, but it can be very effective for severely flooded engines. It involves physically removing the excess fuel from the cylinder.
The Science Behind It: Gravity is your friend here. By inverting the chainsaw, you allow the excess fuel to drain out of the cylinder and carburetor.
Step-by-Step Guide:
- Safety First (You Know the Drill): Engage the chain brake and disconnect the spark plug wire.
- Position the Chainsaw: Find a clear, open area where you can invert the chainsaw without spilling fuel on anything sensitive.
- Invert the Chainsaw: Carefully turn the chainsaw upside down, with the spark plug hole facing downwards.
- Pull the Cord (Gently): Give the starter cord a few gentle pulls. This will help to force the excess fuel out of the cylinder. You should see fuel dripping from the spark plug hole.
- Wait a Few Minutes: Allow the chainsaw to sit inverted for a few minutes to ensure that all the excess fuel has drained out.
- Reinstall the Spark Plug: Reinstall the spark plug and reconnect the spark plug wire.
- Try Starting Again: Set the choke lever to the “run” or “off” position and try starting the chainsaw using the wide-open throttle technique or the normal starting procedure.
Data Point: This method can remove up to 80% of the excess fuel from the cylinder, significantly increasing the chances of starting.
Pro Tip: Be careful not to get fuel on the air filter. Fuel-soaked air filters can restrict airflow and make it even harder to start the chainsaw.
Example: I once used this method on a Stihl MS 290 that had been flooded after being stored improperly. A significant amount of fuel drained out, and the chainsaw started easily after reinstalling the spark plug.
4. The “Air Filter Assessment”
Sometimes, the problem isn’t just in the cylinder. A fuel-soaked or clogged air filter can also contribute to flooding and make it difficult to start the chainsaw.
The Science Behind It: The air filter regulates the amount of air that enters the carburetor. A clogged or fuel-soaked air filter restricts airflow, leading to a rich fuel mixture and potential flooding.
Step-by-Step Guide:
- Safety First (Always!): Engage the chain brake.
- Locate the Air Filter: The air filter is usually located under a cover on the side or top of the chainsaw.
- Remove the Air Filter: Remove the air filter cover and carefully remove the air filter.
- Inspect the Air Filter: Check the air filter for signs of fuel saturation, dirt, or debris.
- Clean or Replace the Air Filter:
- If the air filter is slightly dirty: Clean it by tapping it gently against a hard surface or using compressed air to blow out the dirt.
- If the air filter is fuel-soaked: Wash it with warm, soapy water and allow it to dry completely before reinstalling it.
- If the air filter is heavily soiled or damaged: Replace it with a new air filter.
- Reinstall the Air Filter: Reinstall the air filter and the air filter cover.
- Try Starting Again: Set the choke lever to the “run” or “off” position and try starting the chainsaw using the wide-open throttle technique or the normal starting procedure.
Data Point: A clean air filter can improve engine performance by up to 10% and reduce the risk of flooding.
Pro Tip: Clean or replace your air filter regularly, especially if you’re working in dusty or dirty conditions. I make it a habit to clean mine after every 5 hours of use.
Example: I once had a Stihl MS 250 that was consistently flooding, even after trying the other methods. The air filter was completely clogged with sawdust and fuel. After cleaning the air filter, the chainsaw ran like a champ.
5. The “Carburetor Adjustment (If You Dare)” Method
This method should be considered a last resort, as it involves adjusting the carburetor settings. Incorrect adjustments can lead to poor performance or even engine damage. If you’re not comfortable working on carburetors, it’s best to take your chainsaw to a qualified technician.
The Science Behind It: The carburetor controls the air-fuel mixture that enters the engine. Adjusting the carburetor settings can help to lean out a rich mixture and prevent flooding.
Step-by-Step Guide:
- Safety First (One Last Time!): Engage the chain brake.
- Locate the Carburetor Adjustment Screws: On most Stihl chainsaws, the carburetor adjustment screws are located on the side of the carburetor. There are usually three screws:
- L (Low-Speed): Controls the fuel mixture at idle and low speeds.
- H (High-Speed): Controls the fuel mixture at high speeds.
- LA (Idle Speed): Controls the engine idle speed.
- Adjust the Low-Speed (L) Screw:
- Turn the L screw clockwise (in) to lean out the mixture.
- Turn the L screw counterclockwise (out) to richen the mixture.
- Make small adjustments (1/8 turn at a time) and try starting the chainsaw after each adjustment.
- Adjust the High-Speed (H) Screw (If Necessary):
- The H screw should only be adjusted by experienced technicians. Incorrect adjustments can damage the engine.
- If you suspect that the high-speed mixture is too rich, turn the H screw clockwise (in) slightly.
- Adjust the Idle Speed (LA) Screw:
- Adjust the LA screw to achieve a stable idle speed. The engine should idle smoothly without stalling or racing.
- Test the Chainsaw: After adjusting the carburetor, test the chainsaw under load to ensure that it’s running properly.
Data Point: Properly adjusted carburetors can improve fuel efficiency by up to 15% and extend engine life.
Pro Tip: Take note of the original position of the adjustment screws before making any changes. This will allow you to return to the original settings if necessary.
Example: I once had a Stihl MS 261 that was running too rich, causing it to flood frequently. After carefully adjusting the L screw, the chainsaw ran much smoother and the flooding problem disappeared. However, I always recommend seeking professional help if you’re not comfortable with carburetor adjustments.
Warning: Carburetor adjustments can be tricky. If you’re not comfortable with this procedure, it’s best to take your chainsaw to a qualified technician.
Beyond the Fixes: Preventing Flooding in the First Place
While knowing how to fix a flooded chainsaw is essential, preventing it from happening in the first place is even better. Here are some tips to minimize the risk of flooding:
- Prime Sparingly: Only prime the carburetor a few times, as recommended by the manufacturer. Over-priming is a common cause of flooding.
- Use Fresh Fuel: Old or stale fuel can cause starting problems and increase the risk of flooding. Use fresh, high-quality fuel and mix it with the correct amount of oil. I always use fuel stabilizer, especially when storing the chainsaw for extended periods.
- Store Properly: Store your chainsaw in a dry, well-ventilated area. Avoid storing it with a full tank of fuel, as this can lead to fuel leakage and flooding.
- Regular Maintenance: Keep your chainsaw well-maintained. Clean the air filter regularly, check the spark plug, and replace any worn or damaged parts.
- Understand Your Chainsaw: Read the owner’s manual and familiarize yourself with the specific starting procedures for your model. Different chainsaws may have different starting requirements.
The Broader Picture: Sustainable Wood Processing and Firewood Preparation
While we’ve focused on the immediate problem of a flooded chainsaw, it’s important to remember that wood processing and firewood preparation are part of a larger ecosystem. Sustainable forestry practices are crucial for ensuring the long-term availability of wood resources.
- Sustainable Harvesting: Choose wood from sustainably managed forests. Look for certifications like the Forest Stewardship Council (FSC).
- Efficient Processing: Use efficient wood processing techniques to minimize waste. Properly sized firewood stacks and efficient log splitters can help to reduce waste and maximize the yield.
- Proper Seasoning: Season firewood properly to improve its burning efficiency and reduce emissions. Aim for a moisture content of 20% or less.
- Responsible Burning: Burn firewood responsibly to minimize air pollution. Use a certified wood stove or fireplace and avoid burning wet or unseasoned wood.
Case Study: A Small-Scale Firewood Producer in Vermont
I recently visited a small-scale firewood producer in Vermont who has implemented several sustainable practices. They harvest wood from their own woodlot using selective logging techniques, which minimize the impact on the forest ecosystem. They use an efficient wood processor to cut and split the firewood, and they season it in covered stacks for at least one year. They also offer their customers tips on responsible burning practices. Their commitment to sustainability has not only benefited the environment but has also helped them to build a loyal customer base.
Data Point: Properly seasoned firewood can burn up to 50% more efficiently than unseasoned wood, reducing emissions and saving money.
Costs, Budgeting, and Resource Management
Wood processing and firewood preparation can be both rewarding and cost-effective, but it’s important to consider the costs involved.
- Equipment Costs: Chainsaws, log splitters, axes, wedges, and other tools can represent a significant investment. Consider buying used equipment or renting tools to save money.
- Fuel and Maintenance Costs: Chainsaws and log splitters require fuel and regular maintenance. Factor these costs into your budget.
- Labor Costs: If you’re hiring someone to help you with wood processing or firewood preparation, factor in labor costs.
- Storage Costs: Firewood needs to be stored properly to season effectively. Consider the cost of building or renting a firewood shed.
Resource Management Tips:
- Plan Ahead: Plan your wood processing and firewood preparation activities in advance. This will help you to avoid costly mistakes and ensure that you have the necessary resources.
- Optimize Your Workflow: Streamline your workflow to minimize wasted time and effort.
- Recycle and Reuse: Recycle wood scraps and sawdust for mulch or compost. Reuse old tires or pallets to build firewood racks.
- Negotiate Prices: Don’t be afraid to negotiate prices with suppliers of wood, equipment, or services.
Troubleshooting and Common Pitfalls
Even with the best planning and preparation, things can sometimes go wrong. Here are some common pitfalls to avoid and troubleshooting tips:
- Chainsaw Chain Problems: A dull or improperly tensioned chain can make cutting difficult and increase the risk of kickback. Sharpen your chain regularly and adjust the tension as needed.
- Log Splitter Problems: Log splitters can sometimes jam or malfunction. Make sure to follow the manufacturer’s instructions and use the correct type of hydraulic fluid.
- Firewood Seasoning Problems: Firewood that is not properly seasoned can be difficult to burn and produce excessive smoke. Make sure to stack your firewood properly and allow it to season for at least six months.
- Safety Hazards: Wood processing and firewood preparation can be dangerous. Always wear appropriate safety gear, including eye protection, hearing protection, gloves, and sturdy boots.
Example: I once had a near-miss when a log kicked back from a log splitter and nearly hit me. I learned my lesson and now always stand to the side of the splitter while operating it.
Next Steps and Additional Resources
Now that you know how to start a flooded Stihl chainsaw and have a better understanding of wood processing and firewood preparation, here are some next steps you can take:
- Practice Your Skills: Practice your chainsaw skills in a safe and controlled environment.
- Attend a Workshop: Attend a workshop or seminar on wood processing or firewood preparation.
- Join a Community: Join a local wood processing or firewood preparation community.
- Consult with Experts: Consult with experienced wood processors or arborists for advice and guidance.
Additional Resources:
- Stihl Website: https://www.stihl.com/ (for chainsaw manuals, parts, and service information)
- Forest Stewardship Council (FSC): https://fsc.org/ (for information on sustainable forestry)
- Local Arborist Associations: (for finding qualified arborists in your area)
- Equipment Rental Services: (for renting chainsaws, log splitters, and other tools)
Concluding Thoughts: Embrace the Process
Wood processing and firewood preparation can be challenging, but they can also be incredibly rewarding. There’s something deeply satisfying about taking a raw log and transforming it into a stack of firewood that will keep your home warm and cozy throughout the winter. Embrace the process, learn from your mistakes, and always prioritize safety. And remember, even the most experienced wood processors have had their share of flooded chainsaws. It’s all part of the journey. So, get out there, get your hands dirty, and enjoy the fruits (or should I say, wood) of your labor!
