Stihl Gas Leaf Blower BG 86: Setup, Starting and Care Guide

By Caleb Morgan

Updated November 2026

The Stihl gas leaf blower BG 86 is a lightweight, handheld two-stroke blower built for homeowners who clean driveways, patios, gutters and garden beds. In this guide you will learn how to prepare the machine, mix fuel correctly, start it reliably, use it efficiently and keep it running for years. Most starting problems and early wear come from a handful of avoidable mistakes, and the steps below address each one.

What the BG 86 Is Built For

The BG 86 is a handheld blower in Stihl’s BG line, designed for yards of small to medium size. Manufacturers generally position this model as a lighter alternative to backpack units, suited to quick cleanup jobs rather than large acreage. Because it is a two-stroke engine, it runs on a fuel and oil mixture rather than straight gasoline, and that single fact shapes almost everything about how you maintain it. Before you buy or use one, check the specifications printed in the owner’s manual for engine displacement, air volume and weight, since these vary between model years and regional versions.

Shopping for one? See our guide: 7 Best Stihl Battery Leaf Blower Options Compareds for Home Yards (2026).

Step 1: Unpack and Inspect the Blower

Start with a visual check before you add any fuel. Look for loose or missing fasteners on the handle, the nozzle, and the throttle lever. Confirm the throttle trigger and the lock-out button move freely and return to their rest positions. Check the air filter cover for cracks and make sure the fuel cap seals snugly. If anything is damaged or missing, stop and contact your dealer before running the unit.

Step 2: Mix the Fuel Correctly

Two-stroke engines need oil mixed into the gasoline, and the ratio matters. Stihl specifies its own high-performance two-stroke oil for best results, and the owner’s manual lists the exact mixing ratio for the BG 86. Mixing ratios for Stihl products are commonly listed as 50:1 for their standard two-stroke oil, but always confirm against the manual, because using the wrong ratio can cause lean running and engine damage.

1. Use fresh gasoline with the octane rating recommended in the manual. Avoid fuel stored for more than about 30 days.
2. Use a clean, marked container designed for fuel mixing.
3. Pour in about half the gasoline first.
4. Add the full measured amount of two-stroke oil.
5. Add the remaining gasoline and shake the container thoroughly.
6. Label the container with the date you mixed it.

Never use pure gasoline in the tank, and never guess the ratio. Mixing a small batch at a time keeps the fuel fresh and avoids waste.

Step 3: Start the BG 86

Starting a two-stroke blower is mostly a matter of getting the choke, primer and throttle in the right positions. The sequence below follows the general pattern used across Stihl handheld blowers, but confirm each control’s location in your manual.

Prepare the Machine

• Place the blower on a flat, clear surface with the nozzle pointing away from you and anything fragile.
• Hold the machine firmly with your left hand on the rear handle and your right foot braced if needed.
• Press the primer bulb several times until fuel is visible in it.

Set the Choke and Start

1. Move the choke to the full or closed position for a cold start.
2. Pull the starter rope smoothly until the engine attempts to fire.
3. Once it fires, move the choke to the half or open position.
4. Pull the rope again until the engine runs.
5. Let it idle for about 30 seconds before using full throttle.

Handling a Warm Engine

If the engine is already warm, leave the choke open or off and use a few pulls with the throttle lock disengaged. Flooding is a common problem with two-stroke engines. If you have pulled many times without starting, set the choke to open, pull the rope several times with the throttle fully open to clear excess fuel, then try again with the throttle in the idle position.

Step 4: Use the Blower Efficiently

Good technique saves fuel, reduces fatigue and gets better results. Hold the blower with the nozzle angled slightly downward, around 30 to 45 degrees toward the ground, so the air stream pushes debris forward rather than lifting it into the air. Work in overlapping passes, moving from the far side of the area toward yourself. For wet leaves, use a lower throttle setting and make longer, slower passes. For dry leaves on hard surfaces, you can use higher throttle and move more quickly.

Step 5: Shut Down and Store the Blower

Stop the engine by pressing the stop switch to the off position. Allow the machine to cool for a few minutes before storing it. If you will not use it for more than about 30 days, run the engine until it stalls to clear fuel from the carburetor, or drain the tank and run the engine dry. Store the unit in a dry place away from open flames and heat sources.

Maintenance Checklist

Intervals vary by usage and region, so treat the manual’s maintenance schedule as the authority. If you are unsure about carburetor adjustments or internal repairs, consult an authorized Stihl dealer.

Common Mistakes

• Using pure gasoline. Two-stroke engines require oil in the fuel. Running without it causes rapid, serious engine damage.
• Guessing the mixing ratio. Follow the manual exactly and mix carefully.
• Storing fuel too long. Old fuel gums up the carburetor and causes hard starting.
• Flooding the engine. Repeated pulling with the choke closed floods the cylinder. Use the clear-flood procedure described above.
• Running with a dirty air filter. A clogged filter starves the engine of air, reducing power and increasing wear.
• Neglecting the spark plug. A fouled plug is a frequent cause of no-start and rough running.

Tips for Longer Life

• Keep a small brush and a cloth with your tool kit for quick cleaning after each job.
• Note your fuel mix date on the container so you always know how old it is.
• Wear hearing protection and eye protection whenever you run the blower.
• Keep bystanders, pets and children well clear of the discharge area, since blowers can throw debris and small objects at high speed.
• If the engine runs hot, shut it down and check the cooling fins and air intake before continuing.

Recommended gear

A few accessories make routine care and fuel handling easier. Choose items that fit the BG 86 and the fuel requirements in your manual.

• Stihl two-stroke engine oil. Using the manufacturer’s oil helps ensure the correct lubrication and mixing consistency for your blower. View on Amazon
• Stihl replacement air filter for BG series blowers. A fresh filter restores airflow and protects the engine from dust. View on Amazon
• Fuel mixing container with clear graduations. Accurate measuring prevents ratio errors that can damage the engine. View on Amazon
• Stihl spark plug matched to the BG 86. Replacing the plug at the recommended interval keeps starting reliable. View on Amazon

If you are comparing this model with other handheld options, the guides on Stihl Leaf Blower BG 50: Setup, Starting and Care Guide (2026) and Stihl Gas Backpack Leaf Blower: How to Choose, Start and Maintain One cover related Stihl models in detail. For a broader look at blower categories, see Leaf Blower Types: Handheld, Backpack and Blower-Vac and 6 Best Handheld Gas Leaf Blowers for Yard Cleanup (2026). Readers interested in powering their blower with alternative fuel options can also review Gas Power Leaf Blower Guide: How to Choose, Start and Maintain One.

FAQ

What fuel does the Stihl BG 86 use?

It uses a gasoline and two-stroke oil mixture. Use fresh gasoline with the octane rating listed in the manual, and mix it with the oil ratio specified for your model. Do not run it on straight gasoline.

How long can I store mixed fuel?

Mixed fuel should generally be used within about 30 days. Older fuel can break down, leaving deposits that cause hard starting and carburetor problems.

Why won’t my BG 86 start?

The most common causes are an incorrect choke position, flooding, stale fuel, a fouled spark plug, or a clogged air filter. Check each of these before assuming a major fault.

How do I clear a flooded engine?

Set the choke to open, hold the throttle fully open, and pull the starter rope several times to clear excess fuel. Then set the throttle to idle and try starting again.

How often should I clean the air filter?

Check it regularly and clean it whenever it looks dirty. Follow the manual’s interval, and replace it if it is torn, oily or cannot be cleaned.

Can I use this blower for wet leaves?

Yes, but wet leaves are heavier and need more airflow. Use lower throttle settings with slower, overlapping passes, and expect to do more passes to clear the same area.

When should I take the blower to a dealer?

If the engine runs rough after basic maintenance, produces smoke or unusual noise, or needs carburetor adjustment or internal repair, take it to an authorized Stihl dealer or qualified small-engine technician.

Conclusion

With the right fuel mix, a correct starting sequence and regular maintenance, the Stihl BG 86 can deliver dependable performance for years. Focus on the fundamentals: fresh mixed fuel, a clean air filter, a healthy spark plug and careful technique. Follow the owner’s manual for exact specifications, and consult a professional for any repair beyond routine care.

About Caleb Morgan

Caleb Morgan is part of our editorial team and reviews and edits our garden hand tools & equipment guides, checking product details against manufacturer specifications and owner feedback.