How to Start a Stihl Bg 86 Leaf Blower? Step-by-Step Tutorial

Introduction

The Stihl BG 86 is one of the most popular gas-powered handheld leaf blowers on the market, known for its lightweight design, powerful airflow, and reliability for residential and light commercial use. However, many new owners struggle with How to Start a Stihl Bg 86 Leaf Blower? especially if they are unfamiliar with 2-stroke engine equipment. Unlike electric blowers that start with the push of a button, the BG 86 requires a few specific steps to get the engine running, and small mistakes can lead to frustration, flooded engines, or even damage to the blower over time. This comprehensive guide walks you through every step of starting your Stihl BG 86, from pre-start safety checks to troubleshooting common issues, so you can get to work clearing leaves and debris quickly and safely.

• Understanding Your Stihl BG 86 Leaf Blower
• Pre-Start Safety Checks
• Step-by-Step Guide to Starting a Cold Stihl BG 86
• How to Start a Warm Stihl BG 86
• Cold vs. Warm Start Procedures Comparison
• Essential Maintenance Tips for Reliable Starting
• Common Starting Problems and Fixes
• Best Practices for Long-Term Performance
• Frequently Asked Questions
• Conclusion

Understanding Your Stihl BG 86 Leaf Blower

The Stihl BG 86 is a 2-stroke, gas-powered handheld blower designed for light to medium-duty yard work, including clearing leaves, grass clippings, and light debris from driveways, sidewalks, and lawns. It features a 27.6 cc engine that produces 456 cubic feet per minute of airflow at 265 miles per hour, making it powerful enough for most residential use cases while remaining lightweight enough to operate for extended periods without fatigue.

Key Components That Affect Starting

Several parts of the BG 86 play a critical role in the starting process, and understanding how they work will make troubleshooting far easier if you run into issues:

• Carburetor: The carburetor mixes fuel and air in the correct ratio for combustion. A clogged or improperly adjusted carburetor is one of the most common causes of starting problems for 2-stroke engines.
• Choke: The choke restricts airflow to the carburetor, creating a richer fuel-air mixture that is easier to ignite when the engine is cold. The BG 86 has a lever-style choke with positions for cold start, warm start, and run.
• Primer Bulb: This small rubber bulb on the side of the carburetor pushes fuel directly into the carburetor throat when pressed, eliminating the need for the engine to draw fuel through the idle circuit when cold.
• Air Filter: The air filter prevents dust, debris, and grass clippings from entering the engine. A clogged air filter restricts airflow, making it harder for the engine to draw the correct fuel-air mixture for starting.
• Spark Plug: The spark plug ignites the fuel-air mixture in the combustion chamber. A fouled, worn, or improperly gapped spark plug will fail to ignite the mixture, preventing the engine from starting.
• Fuel System: The BG 86 requires a 50:1 mix of unleaded gasoline and Stihl-approved 2-stroke oil. Old, stale, or improperly mixed fuel is the leading cause of starting issues for this model.

Pre-Start Safety Checks

Before attempting to start your Stihl BG 86, completing a few quick safety checks will reduce the risk of injury, prevent damage to the blower, and make the starting process far more reliable. These checks take less than 2 minutes and should be completed every time you operate the blower:

• Work in a well-ventilated area: Never start the blower in an enclosed space like a garage or shed, as exhaust fumes contain carbon monoxide, a colorless, odorless gas that can be fatal in high concentrations. Always operate the blower outdoors in an open area.
• Wear appropriate protective gear: Safety glasses or goggles are required to protect your eyes from flying debris, and ear protection is recommended to prevent hearing damage from the blower’s loud operation. Wear closed-toe shoes and long pants to protect your feet and legs from debris.
• Place the blower on a flat, stable surface: Make sure the blower is sitting level on the ground, with the air intake clear of leaves, grass, or other debris that could be sucked into the engine. Never attempt to start the blower while holding it, as this can lead to loss of control if the engine starts unexpectedly.
• Check for fuel leaks: Inspect the fuel tank, fuel lines, and carburetor for any signs of cracks, leaks, or damage. If you notice fuel leaking, do not attempt to start the blower. Take it to a certified Stihl service center for repair before use.
• Confirm the stop switch is in the “run” position: The stop switch, located on the handle of the blower, controls the ignition system. If the switch is in the “stop” position, the engine will not start. Make sure the switch is flipped to “run” before attempting to start the blower.

Step-by-Step Guide to Starting a Cold Stihl BG 86

A cold start is required when the engine has been turned off for 30 minutes or longer, or if the blower has been in storage for an extended period. The cold start process uses a richer fuel-air mixture to compensate for the lower temperature of the engine and fuel, making ignition easier. Follow these steps exactly to start your cold BG 86:

Step 1: Prepare the Blower

First, place the blower on a flat, stable surface with the air intake facing away from you and any nearby debris. Release the throttle trigger to ensure it is not stuck in the open position, which can make starting difficult. Confirm the stop switch is in the “run” position, as outlined in the pre-start safety checks. Clear any leaves, grass, or dirt from the air intake screen to ensure unrestricted airflow to the engine.

Step 2: Prime the Carburetor

Locate the primer bulb on the side of the carburetor, near the fuel tank. Press the primer bulb slowly 3 to 5 times, pausing briefly between each press. You will see fuel begin to fill the bulb, and after 3 to 5 presses, the bulb should remain partially filled with fuel. This step pushes fuel directly into the carburetor throat, eliminating air pockets and ensuring the engine has immediate access to fuel when you pull the starter cord. Skipping this step is one of the most common reasons cold starts fail for new BG 86 owners.

Step 3: Set the Choke

Locate the choke lever on the side of the blower, near the carburetor. For a cold start, pull the choke lever fully to the closed position, which is usually marked with a snowflake icon or the word “COLD” on the lever. This closed position restricts airflow to the carburetor, creating a richer fuel-air mixture that ignites more easily when the engine is cold. Do not attempt to use the warm start choke position for a cold engine, as this will create a mixture that is too lean to ignite.

Step 4: Activate the Starter

Grip the starter handle firmly with one hand, and hold the blower securely with the other to keep it stable on the ground. Pull the starter cord slowly at first until you feel resistance, which indicates the piston is at the top of its compression stroke. Then pull the cord quickly and firmly in one smooth motion. Do not pull the cord all the way out, as this can damage the recoil spring; let the cord recoil fully after each pull. Repeat this process 3 to 5 times, waiting 10 seconds between each pull to allow the fuel to ignite. If the engine does not start after 5 pulls, wait 2 minutes before attempting again to avoid flooding the combustion chamber with excess fuel.

How to Start a Warm Stihl BG 86

A warm start is required when the engine has been running within the last 30 minutes, and the engine and fuel are still at operating temperature. The warm start process is simpler than the cold start, as the engine does not need a rich fuel-air mixture to ignite. Follow these steps to start a warm BG 86:

1. Place the blower on a flat, stable surface, release the throttle trigger, and confirm the stop switch is in the “run” position.
2. Set the choke lever to the warm start position, which is partially open and usually marked with a sun icon or the word “WARM”. If the engine was running very recently (within the last 10 minutes), you may be able to start it with the choke fully open, in the “run” position.
3. Pull the starter cord 1 to 2 times firmly, using the same slow-then-quick motion as the cold start. The engine should start immediately. If it does not start after 2 pulls, add a small amount of choke (move the lever halfway between warm and cold) and pull 1 more time. Avoid using the full cold choke position on a warm engine, as this will flood the engine with excess fuel and make starting impossible until the fuel clears.

Cold vs. Warm Start Procedures Comparison

While the starting process for the Stihl BG 86 is straightforward, the steps differ significantly depending on whether the engine is cold or warm. Using the wrong procedure for your engine’s temperature is one of the most common causes of starting frustration for new owners. The table below outlines the key differences between cold and warm start procedures for the BG 86:

As a general rule, if you are unsure whether your engine is cold or warm, start with the cold start procedure. If the engine does not start after 3 pulls, wait 10 seconds and try again. If you smell raw fuel after attempting to start, the engine is likely flooded, and you should switch to the warm start procedure with the choke fully open to clear the excess fuel.

Essential Maintenance Tips for Reliable Starting

Regular maintenance is the single most effective way to ensure your Stihl BG 86 starts reliably every time, even after extended periods of storage. Neglecting basic maintenance is the leading cause of preventable starting issues for this model. Follow these tips to keep your blower in top starting condition:

• Use fresh, properly mixed fuel: Stihl recommends a 50:1 oil-to-gas ratio (2.6 ounces of Stihl-approved 2-stroke oil per gallon of unleaded gasoline with 89 octane or higher). Never use fuel with more than 10% ethanol content, as ethanol can degrade rubber fuel lines, corrode internal carburetor components, and cause starting issues. Mix only enough fuel for 30 days of use, as stale fuel will break down over time and lose its combustibility. If you need to store fuel for longer than 30 days, add a fuel stabilizer to prevent degradation.
• Clean the air filter regularly: Inspect the air filter after every 10 hours of operation, and clean it with warm soapy water if it is dirty or clogged. Allow the filter to dry completely before reinstalling it. A clogged air filter restricts airflow to the engine, making starting difficult and reducing the blower’s power output.
• Inspect and replace the spark plug annually: The spark plug should be replaced every 100 hours of operation, or once per year, whichever comes first. A fouled or worn spark plug will fail to ignite the fuel-air mixture, preventing the engine from starting. When replacing the spark plug, use only Stihl-approved parts to ensure proper fit and performance.
• Clean the muffler spark arrestor: The spark arrestor, located on the muffler, prevents hot sparks from exiting the exhaust and causing fires. Carbon buildup can clog the spark arrestor over time, restricting exhaust flow and making starting difficult. Clean the spark arrestor every 25 hours of operation with a wire brush to remove carbon deposits.
• Store the blower properly during off-seasons: If you will not use the blower for more than 30 days, drain all fuel from the tank and carburetor to prevent stale fuel from clogging the fuel system. Store the blower in a cool, dry place, away from direct sunlight and extreme temperatures.

Common Starting Problems and Fixes

Even with proper maintenance, you may occasionally run into starting issues with your Stihl BG 86. Below are the most common problems owners face, along with practical fixes to get your blower running again without a trip to the repair shop:

Engine Cranks but Won’t Start

If you pull the starter cord and the engine turns over but does not ignite, the issue is almost always related to fuel delivery or ignition. First, confirm you are using fresh 50:1 mixed fuel, and that you primed the carburetor correctly for a cold start. Next, remove the spark plug and inspect it for fouling, wear, or carbon buildup. If the spark plug is dirty, clean it with a wire brush or replace it with a new Stihl-approved spark plug. Reinstall the spark plug, set the choke to the cold start position, and pull the starter cord 3 to 4 times. If the engine still does not start, check the air filter for clogs, and clean or replace it if needed.

Engine Starts Then Dies Immediately

If the engine starts for a second or two then shuts off, the issue is usually related to the choke position or a clogged carburetor. First, make sure the choke is fully open (in the “run” position) after the engine starts. If the choke is still partially closed, the engine will not get enough air to stay running. If the choke is open and the engine still dies, the carburetor may be clogged with old fuel or debris. Try cleaning the carburetor with a carburetor cleaner spray, or take the blower to a certified Stihl service center for a professional cleaning.

Engine Floods and Won’t Start

If you smell raw fuel after attempting to start the blower, or if the starter cord feels unusually hard to pull, the engine is likely flooded with excess fuel. To fix this, set the choke lever to the fully open (run) position, then pull the starter cord 5 to 6 times to clear the excess fuel from the combustion chamber. Wait 5 minutes to allow the fuel to evaporate before attempting to start again. To avoid flooding in the future, do not exceed 5 starter pulls for a cold start without waiting 10 seconds between attempts, and never use the full cold choke on a warm engine.

Starter Cord is Stuck or Hard to Pull

If the starter cord is stuck, hard to pull, or does not recoil fully, do not force it, as this can damage the recoil spring or starter mechanism. First, check for debris tangled in the starter housing, such as leaves or grass clippings. Remove any debris and try pulling the cord again. If the cord is still stuck, the recoil spring may be broken or worn, and the starter assembly will need to be replaced. Take the blower to a certified Stihl service center for repair if you are not comfortable disassembling the starter mechanism yourself.

Best Practices for Long-Term Performance

Following a few simple best practices will extend the life of your Stihl BG 86, reduce the frequency of starting issues, and keep it running at peak performance for years to come:

• Use only Stihl-approved parts and fluids: Using generic 2-stroke oil or non-approved spark plugs and air filters can lead to poor performance, increased emissions, and premature wear of internal engine components. Stihl parts are engineered specifically for the BG 86’s engine, ensuring optimal performance and reliability.
• Clean the blower after each use: After each use, wipe down the exterior of the blower with a damp cloth to remove grass, leaves, and debris that can clog the air intake or damage the plastic housing. Remove the air filter and tap it gently to remove loose debris, even if you do not need to wash it yet.
• Avoid storing the blower with fuel in the tank for long periods: If you will not use the blower for more than 30 days, drain all fuel from the tank and carburetor to prevent stale fuel from clogging the fuel system. If you must store the blower with fuel in the tank, add a fuel stabilizer to prevent degradation, and run the engine for 2 to 3 minutes to circulate the stabilized fuel through the carburetor.
• Schedule annual tune-ups with a Stihl dealer: Even with regular at-home maintenance, an annual tune-up from a certified Stihl service center will catch small issues before they become major problems. A professional tune-up includes cleaning the carburetor, adjusting the idle speed, inspecting the fuel system, and replacing worn parts as needed.
• Operate the blower correctly: Avoid running the blower at full throttle for extended periods, as this can overheat the engine and cause premature wear. Use the appropriate throttle setting for the task at hand, and take breaks if you are using the blower for more than 30 minutes at a time.

Frequently Asked Questions

Below are answers to the most common questions owners have about starting and maintaining their Stihl BG 86 leaf blower:

Why won’t my Stihl BG 86 start after sitting all winter?

If your blower has been in storage all winter, the most common causes of starting issues are stale fuel and a clogged air filter. Start by draining all old fuel from the tank and carburetor, then mix fresh 50:1 Stihl-approved 2-stroke fuel. Remove and clean the air filter with warm soapy water, let it dry completely before reinstalling. Prime the carburetor 5–6 times, set the choke to the full cold start position, and pull the starter cord firmly 4–5 times, waiting 10 seconds between attempts. If it still won’t start, inspect the spark plug for fouling or wear, and replace it if needed. If these steps do not resolve the issue, take the blower to a certified Stihl service center to check for carburetor clogs or internal engine damage.

Can I use regular gasoline in my Stihl BG 86?

Yes, you can use regular unleaded gasoline with an octane rating of 89 or higher, but you must mix it with Stihl-approved 2-stroke oil at a 50:1 ratio (2.6 ounces of oil per gallon of gas). Never use gasoline with more than 10% ethanol content, as high-ethanol fuels can damage the blower’s fuel system, corrode internal components, and cause starting issues. For best performance and longevity, use ethanol-free gasoline if available in your area.

How often should I replace the air filter on my BG 86?

Stihl recommends inspecting the air filter after every 10 hours of operation, and cleaning it with warm soapy water if it is dirty or clogged. You should replace the air filter every 100 hours of use, or once per year, whichever comes first. If you regularly use the blower in dusty or debris-heavy environments, check and clean the filter more frequently, and replace it sooner if it shows signs of tearing or excessive wear. A clogged air filter will restrict airflow to the engine, making starting difficult and reducing the blower’s power output.

What does the purge valve do on the Stihl BG 86?

The purge valve, located on the side of the carburetor, is a small rubber button that you can press to manually push fuel into the carburetor. It is used primarily when the blower has been stored for an extended period, or if the carburetor has run out of fuel. Pressing the purge valve 3–5 times will fill the carburetor with fuel, eliminating air pockets that can prevent the engine from starting. Note that the purge valve is not a replacement for the primer bulb, which is used for regular cold starts.

Conclusion

Starting a Stihl Bg 86 Leaf Blower? is a simple process once you understand the difference between cold and warm start procedures, and follow the correct steps for your engine’s temperature. By completing pre-start safety checks, priming the carburetor correctly for cold starts, and performing regular maintenance like cleaning the air filter and using fresh fuel, you can avoid most common starting issues and keep your blower running reliably for years. If you do run into problems, refer to the common fixes outlined in this guide before taking your blower to a repair shop, as most starting issues are easy to resolve at home with basic tools and a little know-how. With proper care, your Stihl BG 86 will be a reliable tool for all your leaf and debris clearing needs for seasons to come.