Introduction
The Stihl BG 86 is one of the most popular lightweight, gas-powered leaf blowers on the market, beloved for its powerful airflow, ergonomic design, and low emissions. But if you’ve ever struggled to get it running on the first pull—or the fifth—you’re not alone. Many new and even experienced users hit snags when learning How to Start Stihl Bg 86 Leaf Blower? especially if they’re unfamiliar with 2-cycle engine operation or skip key pre-start steps. This complete guide walks you through every step of starting your BG 86, from cold starts on a chilly morning to warm starts mid-job, plus troubleshooting tips, maintenance advice, and safety best practices to keep your blower running smoothly for years. Whether you’re a first-time user or just need a quick refresher, you’ll find all the information you need right here.
- Pre-Start Safety Checks You Can’t Skip
- Familiarize Yourself With Stihl BG 86 Controls
- Fuel Preparation For Smooth, Reliable Starting
- Step-by-Step Cold Start Procedure For Stihl BG 86
- Warm Start Procedure For Quick, Hassle-Free Use
- Common Starting Issues And Quick Fixes
- Maintenance Tips To Prevent Future Starting Problems
- Proper Fuel Storage Best Practices
- Troubleshooting Persistent Starting Failures
- Ongoing Safety Tips For Stihl BG 86 Use
- Frequently Asked Questions About Starting Stihl BG 86
- Conclusion
Pre-Start Safety Checks You Can’t Skip
Before you even touch the starter cord, taking 2 minutes to run through these safety checks will prevent injury, avoid damaging your blower, and make starting far easier. Skipping these steps is one of the most common reasons users struggle when learning How to Start Stihl Bg 86 Leaf Blower? even if they’ve done it before.
First, inspect the work area. Clear away any loose debris, rocks, or toys that could be thrown by the blower’s high-velocity air. Make sure children and pets are at least 50 feet away from the area before you start the engine. Next, check the blower itself for visible damage: look for cracks in the fuel tank, frayed starter cord, or loose screws on the fan housing. If you notice any damage, do not attempt to start the blower until it’s repaired.
Wear proper personal protective equipment (PPE) before starting: safety glasses or goggles to protect your eyes from debris, ear protection to guard against loud engine noise, and non-slip closed-toe shoes to prevent slips on wet or uneven ground. If you have long hair, tie it back, and avoid loose clothing that could get caught in the moving parts of the blower.
Finally, confirm the blower is on a flat, stable surface. Starting it on a slope can cause fuel to flow incorrectly into the carburetor, leading to flooding or hard starts. Place the blower on level ground, and make sure the air intake on the side of the engine is not blocked by grass, leaves, or other debris.
Familiarize Yourself With Stihl BG 86 Controls
The Stihl BG 86 has four key controls that directly impact starting success. If you’re not sure what each one does, you’ll likely set them incorrectly and struggle to get the engine running. Let’s break down each control so you know exactly how to position them for a smooth start.
On/Off Ignition Switch
Located on the side of the handle, this small rocker switch controls power to the spark plug. For starting, this switch must be in the “I” (on) position. If it’s set to “O” (off), the engine will not get a spark, no matter how many times you pull the starter cord. Many users accidentally flip this switch to “off” after storing the blower, leading to confusion when they can’t get it started.
Choke Lever Position
The choke lever is a small sliding switch located near the primer bulb on the side of the engine. Its job is to restrict airflow into the carburetor to create a richer fuel mixture for cold starts. For a cold start, the choke should be set to the “full choke” position (usually marked with a rabbit icon or the word “cold”). For warm starts, the choke should be set to the “half choke” or “run” position (marked with a turtle icon or the word “warm”).
Primer Bulb Function
The primer bulb is a small, soft rubber bulb located next to the choke lever. Pressing it 3 to 5 times before starting pushes fuel from the tank into the carburetor, eliminating the need for excessive priming and reducing the risk of flooding. If the primer bulb feels hard when you press it, that’s a sign there’s no fuel in the line, which means you need to refill the tank or check for a clogged fuel line.
Throttle Lock Mechanism
The throttle lock is a small lever on the handle that holds the throttle in the open position. For starting, you do not need to engage the throttle lock; in fact, doing so can flood the engine with too much fuel. Make sure the throttle lock is released, and the throttle trigger is fully closed, before you pull the starter cord.
Fuel Preparation For Smooth, Reliable Starting
One of the most common causes of starting issues with the Stihl BG 86 is incorrect or stale fuel. Unlike 4-cycle engines that use straight gasoline, the BG 86 has a 2-cycle engine that requires a specific mix of gasoline and 2-cycle oil to run properly. Using the wrong fuel mix, or fuel that’s been sitting for too long, will lead to hard starts, poor performance, and even permanent engine damage.
Correct 2-Cycle Fuel Mix Ratio
Stihl recommends a 50:1 fuel-to-oil ratio for the BG 86, meaning 50 parts gasoline to 1 part 2-cycle oil. For a standard 1-gallon gas can, that’s 2.6 ounces of 2-cycle oil mixed with 1 gallon of fresh, unleaded gasoline with an octane rating of 89 or higher. Never use gasoline with more than 10% ethanol (E10), as ethanol breaks down quickly and can damage the engine’s internal components. If you don’t want to mix your own fuel, Stihl sells pre-mixed 50:1 fuel that is ethanol-free and formulated specifically for their 2-cycle tools, which is a great option for users who only use their blower occasionally.
Why Fresh Fuel Matters
Even if you mix the correct 50:1 ratio, fuel that’s been sitting in the tank for more than 30 days will start to break down, especially if it contains ethanol. Old fuel becomes gummy, clogs the carburetor jets, and makes starting extremely difficult. Always empty the fuel tank before storing the BG 86 for more than a month, or use a fuel stabilizer to extend the life of mixed fuel up to 6 months.
Step-by-Step Cold Start Procedure For Stihl BG 86
A cold start is any time you’re starting the blower after it has been sitting for at least 30 minutes, or if the engine is cool to the touch. Follow these steps exactly to master How to Start Stihl Bg 86 Leaf Blower? on the first pull, even in cold weather:
- Fill the fuel tank: Start with fresh, correctly mixed 50:1 fuel. Do not overfill the tank; leave about 1/2 inch of space at the top to allow for fuel expansion as the engine warms up. Screw the fuel cap on tightly to prevent leaks.
- Set the ignition switch to “I”: Flip the on/off switch on the handle to the “on” position to activate the spark plug.
- Engage full choke: Slide the choke lever to the full choke (rabbit) position to create a rich fuel mixture for the cold engine.
- Prime the carburetor: Press the primer bulb 3 to 5 times, until you see fuel begin to flow into the clear fuel line connected to the carburetor. If the bulb doesn’t fill with fuel after 5 presses, check that the fuel tank has fuel and the fuel line isn’t clogged.
- Set the blower on flat ground: Place the BG 86 on a level surface, making sure the air intake is not blocked.
- Pull the starter cord: Grip the starter handle firmly, pull the cord slowly until you feel resistance, then pull it quickly and smoothly 3 to 4 times. Do not pull the cord all the way out, and do not let go of the handle suddenly—this can damage the starter mechanism.
- Adjust choke once the engine fires: As soon as the engine sputters to life (even if it dies immediately after), slide the choke lever to the half choke (turtle) position.
- Pull the cord 1 to 2 more times: The engine should start and run smoothly. Let it idle for 30 seconds to warm up before engaging the throttle.
- Disengage the choke fully: Once the engine is warm, slide the choke lever to the “run” (off) position so the engine gets the correct air-fuel ratio for normal operation.
Warm Start Procedure For Quick, Hassle-Free Use
If you’re starting the BG 86 less than 30 minutes after you last turned it off (for example, if you paused to move a pile of leaves and need to start it again), you can use the warm start procedure to cut down on wait time and avoid flooding the engine:
- Make sure the ignition switch is still in the “I” (on) position. You do not need to turn it off and on again between uses if you’re pausing for less than 30 minutes.
- Set the choke lever to the half choke (turtle) position. Do not use full choke for a warm engine, as this will dump too much fuel into the carburetor and cause flooding.
- Press the primer bulb 1 to 2 times to add a small amount of fuel to the carburetor.
- Pull the starter cord 1 to 2 times. The engine should start immediately. If it doesn’t start after 2 pulls, switch to the full cold start procedure to avoid flooding.
- Let the engine idle for 10 to 15 seconds before engaging the throttle to clear any excess fuel from the carburetor.
Common Starting Issues And Quick Fixes
If you’ve followed all the steps for How to Start Stihl Bg 86 Leaf Blower? and still can’t get it running, the table below outlines the most common issues, their root causes, and quick fixes to get you back to work fast:
| Issue | Common Cause | Quick Fix |
|---|---|---|
| Engine won’t turn over when pulling the starter cord | Empty fuel tank, closed fuel shutoff valve, or dead spark plug | Refill with fresh 50:1 fuel, open the fuel shutoff valve (if equipped), or replace the spark plug |
| Engine starts then dies immediately | Incorrect choke position, stale fuel, or clogged air filter | Adjust choke to half or run position, drain old fuel and replace with fresh mix, clean or replace air filter |
| Excessive smoke coming from the exhaust during start | Choke is set to full position for a warm engine, or too much oil in the fuel mix | Slide choke to half or run position, let engine idle until smoke clears, or drain fuel and mix a fresh 50:1 ratio |
| Starter cord is hard to pull, or won’t pull at all | Engine is flooded with fuel, or starter mechanism is jammed | Wait 10 to 15 minutes for excess fuel to evaporate, then try starting again; if the cord still won’t pull, disassemble the starter to check for jams |
| Engine runs but has very low power | Clogged carburetor jets, dirty air filter, or incorrect fuel mix | Clean the carburetor with a carburetor cleaner, clean or replace the air filter, and confirm you’re using the correct 50:1 fuel ratio |
If you’re still having trouble after trying these fixes, move on to the more advanced troubleshooting steps later in this guide.
Maintenance Tips To Prevent Future Starting Problems
Regular maintenance is the best way to avoid starting issues altogether. A well-maintained Stihl BG 86 will start on the first pull almost every time, even after years of use. Follow these simple maintenance tasks to keep your blower in top shape:
Air Filter Care
The air filter prevents dirt and debris from entering the engine’s carburetor. A clogged air filter restricts airflow, leading to a rich fuel mixture that makes starting difficult and causes poor performance. Clean the air filter after every 5 hours of use by tapping it gently to remove loose debris, then washing it with warm soapy water and letting it dry completely before reinserting it. Replace the air filter every 6 months, or sooner if it’s torn or heavily soiled.
Spark Plug Maintenance
The spark plug provides the spark that ignites the fuel-air mixture in the engine. A fouled or worn spark plug will not produce a strong enough spark to start the engine. Inspect the spark plug every 25 hours of use, or if you notice starting issues. Clean off any carbon buildup with a wire brush, and replace the spark plug if the electrode is worn or damaged. Stihl recommends using the Champion RCJ-7Y spark plug for the BG 86 for optimal performance.
Carburetor Adjustment Basics
Over time, the carburetor’s jets can become clogged with old fuel or debris, leading to incorrect air-fuel ratios that make starting difficult. The BG 86 has three adjustment screws on the side of the carburetor: the low-speed (L) screw, high-speed (H) screw, and idle speed (LA) screw. If you’re comfortable making small adjustments, you can tune the carburetor to improve starting: turn the L and H screws clockwise until they are lightly seated, then turn them counterclockwise 1.5 turns to start. Adjust the LA screw to set the idle speed so the engine runs smoothly without dying. If you’re not comfortable adjusting the carburetor yourself, take the blower to a Stihl authorized service center for professional tuning.
Proper Fuel Storage Best Practices
As we mentioned earlier, stale fuel is one of the top causes of starting issues with the Stihl BG 86. Following these fuel storage best practices will keep your fuel fresh and your blower ready to start whenever you need it:
- Always use a dedicated, airtight fuel can for 2-cycle fuel mixes. Never store mixed fuel in the blower’s tank for more than 30 days.
- Add a fuel stabilizer to mixed fuel if you plan to store it for more than a month. Fuel stabilizer prevents ethanol from breaking down and keeps fuel fresh for up to 6 months.
- Store fuel cans in a cool, dry place away from direct sunlight, sparks, or open flames. Never store fuel in your home or garage near heat sources.
- Label all fuel cans clearly with the mix ratio and date you mixed the fuel, so you always know how old it is.
- Never use fuel that smells sour or looks discolored, as this is a sign it has gone bad and will damage your engine.
Troubleshooting Persistent Starting Failures
If you’ve tried all the quick fixes and maintenance steps above and still can’t get your BG 86 to start, it’s time to dig deeper. Here are the most common advanced issues that cause persistent starting failures:
Clogged fuel line: Over time, old fuel can leave gummy residue in the fuel line, blocking fuel from reaching the carburetor. To check for a clogged fuel line, disconnect the line from the carburetor and blow through it. If air doesn’t flow freely, replace the fuel line.
Faulty spark plug wire: If the spark plug is clean and new but the engine still won’t start, the spark plug wire may be damaged or disconnected. Remove the spark plug wire and check for cracks or fraying. Use a spark tester to confirm the wire is delivering a strong spark; if not, replace the wire.
Carburetor rebuild needed: If the carburetor jets are severely clogged, cleaning them may not be enough. A full carburetor rebuild, which involves replacing the jets, gaskets, and seals, will restore proper fuel flow. You can purchase a carburetor rebuild kit for the BG 86 online or at most hardware stores, or take the blower to a Stihl service center for a professional rebuild.
Compression issues: If the engine has low compression, it will not be able to ignite the fuel-air mixture properly. Low compression is usually caused by worn piston rings or a damaged cylinder, which requires professional repair. If you notice low power, hard starting, and excessive smoke even after maintenance, take the blower to a Stihl authorized dealer to check the compression.
Ongoing Safety Tips For Stihl BG 86 Use
Starting your blower safely is just the first step. Follow these ongoing safety tips to avoid injury and keep your blower in good condition:
- Never operate the blower while under the influence of alcohol, drugs, or medication that makes you drowsy or impairs your judgment.
- Always turn off the engine and let it cool completely before refueling, performing maintenance, or storing the blower. A hot engine can ignite fuel vapors, causing a fire or explosion.
- Never point the blower nozzle at people, animals, or windows. The high-velocity air can throw debris at speeds of up to 200 mph, causing serious injury or damage.
- Use the blower only in well-ventilated areas. Running the engine in an enclosed space can expose you to toxic carbon monoxide fumes, which are odorless and deadly.
- Disconnect the spark plug wire before performing any maintenance on the blower to prevent accidental starting.
- Keep the blower away from heat sources, sparks, or open flames when operating or storing it.
Frequently Asked Questions About Starting Stihl BG 86
Below are answers to the most common questions users have when learning How to Start Stihl Bg 86 Leaf Blower?
Why does my Stihl BG 86 only start when the choke is full?
If your blower only runs with the choke fully engaged, that’s a sign the carburetor is not delivering the correct air-fuel ratio. This is usually caused by a clogged idle jet or a misadjusted carburetor. Clean the carburetor jets first, and if that doesn’t fix the issue, adjust the low-speed screw on the carburetor or take the blower to a Stihl service center for tuning.
Can I use regular gasoline without 2-cycle oil in my Stihl BG 86?
No. The Stihl BG 86 has a 2-cycle engine that requires oil mixed with gasoline to lubricate the internal moving parts. Running straight gasoline will cause the engine to seize permanently within minutes of operation, requiring a full engine rebuild or replacement.
How many times should I pull the starter cord before giving up?
If you’ve followed all the starting steps correctly and the engine hasn’t started after 6 to 8 pulls, stop pulling the cord. Continuing to pull a flooded engine will make the problem worse. Wait 10 to 15 minutes for excess fuel to evaporate, then try the cold start procedure again. If it still doesn’t start, move on to troubleshooting steps for fuel, spark, and compression issues.
What temperature is too cold to start my Stihl BG 86?
The Stihl BG 86 can start in temperatures as low as 0°F (-18°C), but you may need to take extra steps in very cold weather. Use fresh, winter-grade gasoline (which has less ethanol and resists gelling in cold temperatures), prime the carburetor an extra 1 to 2 times, and let the engine idle for an extra 30 seconds after starting to warm up before engaging the throttle.
Do I need to use Stihl brand 2-cycle oil?
While Stihl recommends their own brand of 2-cycle oil for optimal performance and engine longevity, you can use any high-quality 2-cycle oil that is formulated for 50:1 mix ratios. Avoid using automotive 2-cycle oil, as it is not designed for air-cooled engines and can leave harmful deposits in the carburetor.
Conclusion
Learning How to Start Stihl Bg 86 Leaf Blower? doesn’t have to be a frustrating process. By following the pre-start safety checks, using the correct fuel mix, setting the controls properly, and following the step-by-step cold and warm start procedures outlined in this guide, you’ll be able to get your blower running quickly and reliably every time. Regular maintenance, proper fuel storage, and quick fixes for common issues will keep your BG 86 in top condition for years of reliable use. If you do run into persistent starting problems that you can’t resolve on your own, don’t hesitate to take your blower to a Stihl authorized service center for professional help. With a little practice, you’ll be clearing leaves and debris faster than ever, with no more struggling with a stubborn starter cord.