How to Start a Stihl F591r Weed Eater? Stihl FS591R Start Guide

Introduction

The Stihl FS 591 R is a professional‑grade brushcutter designed for demanding landscaping and forestry work. Its 2‑stroke engine delivers high torque and reliable cutting performance, but getting it started correctly is essential for safety and longevity. This guide walks you through everything you need to know about How to Start a Stihl F591r Weed Eater? from pre‑start checks to troubleshooting common issues. Whether you are a seasoned operator or a first‑time user, following the proper procedure will reduce wear, prevent flooding, and ensure the machine runs smoothly every time you pull the starter rope.

• Understanding the Stihl FS 591 R
• Safety Precautions Before Starting
• Required Tools and Materials
• Pre‑Start Inspection Checklist
• Step‑by‑Step Starting Procedure
• Cold Start vs Warm Start Differences
• Troubleshooting Common Starting Issues
• Maintenance Tips for Reliable Starts
• Comparison: Stihl FS 591 R vs Other Professional Trimmers
• Best Practices for Long‑Term Performance
• Common Mistakes to Avoid
• Frequently Asked Questions
• Conclusion

Understanding the Stihl FS 591 R

The FS 591 R belongs to Stihl’s professional line of brushcutters. It features a 59.8 cc 2‑stroke engine that produces 3.5 kW (4.7 hp) at 9,500 rpm. The machine uses a manual recoil starter, a primer bulb, and a choke lever that work together to deliver a reliable cold start. The fuel system is a diaphragm carburetor with a built‑in fuel pump, which means the primer bulb must be pressed several times to draw fuel into the carburetor before the first pull. Understanding these components helps you appreciate why each step in the starting sequence matters.

Key components include:

• Recoil starter – the pull‑rope mechanism that spins the crankshaft.
• Primer bulb – pumps fuel from the tank into the carburetor.
• Choke lever – enriches the air‑fuel mixture for cold starts.
• Throttle trigger – controls engine speed once running.
• Stop switch – cuts ignition instantly for safety.

Familiarity with these parts reduces the chance of operator error and makes the starting routine second nature.

Safety Precautions Before Starting

Safety is the foundation of any equipment operation. Before you even think about pulling the starter rope, complete the following checks:

• Wear appropriate personal protective equipment: safety glasses, hearing protection, gloves, long pants, and sturdy boots.
• Clear the work area of bystanders, pets, and flammable debris.
• Inspect the cutting attachment for damage; a cracked blade can become a projectile.
• Ensure the fuel mixture is fresh (50:1 ratio of gasoline to 2‑stroke oil) and stored in an approved container.
• Verify that the stop switch is in the “ON” position; the engine will not start if it is set to “OFF”.
• Check that the throttle trigger moves freely and returns to idle when released.

Neglecting any of these items can lead to injury or equipment damage, so treat the checklist as mandatory, not optional.

Required Tools and Materials

Having the right supplies on hand streamlines the starting process and prevents interruptions:

• Fresh 50:1 pre‑mixed fuel or separate gasoline and 2‑stroke oil for mixing.
• Clean funnel for fueling without spills.
• Shop towel or rag for wiping the primer bulb and choke lever.
• Spark plug wrench (usually 13 mm) for occasional plug inspection.
• Owner’s manual for model‑specific torque specs and diagrams.

Keep these items in a dedicated tool bag near the machine so you never waste time searching for them.

Pre‑Start Inspection Checklist

Perform a quick visual and functional inspection each time you prepare to start the FS 591 R:

1. Fuel level – Confirm the tank is at least ¼ full; low fuel can cause the primer to draw air.
2. Fuel lines – Look for cracks, kinks, or loose connections.
3. Air filter – Remove the cover and ensure the filter is clean; a clogged filter starves the engine of air.
4. Spark plug – Check for fouling or excessive gap; replace if the electrode is worn.
5. Cutting head – Verify the blade or line is securely fastened and not excessively worn.
6. Throttle and stop switch – Operate each to confirm smooth action.

Completing this checklist takes less than two minutes and dramatically reduces the likelihood of a no‑start situation.

Step‑by‑Step Starting Procedure

Follow these steps in order every time you need to start the brushcutter. The sequence works for both cold and warm engines; the only difference is the choke position, which is noted in the next section.

1. Set the stop switch to ON. The engine will not fire if the switch is OFF.
2. Place the machine on a flat, stable surface. Keep the cutting head clear of the ground.
3. Press the primer bulb 5–7 times until you see fuel fill the bulb. This primes the carburetor.
4. Move the choke lever to the CLOSED (full choke) position for a cold start. For a warm engine, leave it in the OPEN (run) position.
5. Set the throttle trigger to the START (half‑throttle) position. Some operators hold the trigger slightly open; the FS 591 R has a detent that holds it there.
6. Grip the front handle firmly with your left hand and place your right foot on the rear handle for stability.
7. Pull the starter rope slowly until you feel resistance, then give a brisk, full‑length pull. Do not yank; a smooth, strong pull engages the flywheel reliably.
8. If the engine fires but does not continue running, move the choke to the HALF position (if equipped) and pull again.
9. Once the engine runs steadily, gradually move the choke to the OPEN (run) position.
10. Allow the engine to warm up for 30–60 seconds at idle before applying full throttle.

Repeating this routine builds muscle memory and ensures consistent starts.

Cold Start vs Warm Start Differences

The primary difference between a cold and warm start is the choke setting. A cold engine requires a richer mixture, so the choke is fully closed. A warm engine already has residual heat and fuel in the combustion chamber, so the choke should be open or only partially closed. Using the wrong choke position leads to flooding (too rich) or lean running (too lean), both of which make starting difficult. The primer bulb presses remain the same for both conditions because the carburetor must be primed regardless of temperature.

Quick reference:

• Cold start: Choke CLOSED, primer 5–7 presses, throttle at START.
• Warm start: Choke OPEN, primer 2–3 presses (just to refresh fuel), throttle at START.

Adjusting the choke correctly saves time and prevents unnecessary wear on the starter mechanism.

Troubleshooting Common Starting Issues

Even with perfect technique, the FS 591 R may refuse to start. Use this decision tree to isolate the problem:

• No spark: Check the stop switch, inspect the spark plug for fouling, and test with a spark tester. Replace the plug if necessary.
• Engine cranks but won’t fire: Verify fuel delivery – ensure the primer bulb fills, fuel lines are intact, and the tank vent is clear.
• Engine fires then dies: Likely a choke issue. Move choke to HALF or OPEN and retry. Also check for a clogged air filter.
• Hard pulling or rope snaps back: The recoil spring may be worn or the flywheel key sheared. Inspect the starter assembly.
• Excessive smoke on start: Over‑rich mixture. Reduce primer presses, ensure choke is not left closed too long.

Most issues resolve with basic maintenance; persistent problems warrant a visit to an authorized Stihl dealer.

Maintenance Tips for Reliable Starts

Regular upkeep keeps the starting system in top shape:

• Clean the air filter every 25 hours of operation; replace annually.
• Replace the spark plug every 100 hours or at the start of each season.
• Drain old fuel if the machine will sit for more than 30 days; stale gasoline gumms the carburetor.
• Lubricate the recoil starter lightly with a few drops of light oil on the spring housing.
• Inspect the primer bulb for cracks; a cracked bulb leaks air and prevents proper priming.
• Sharpen or replace the cutting blade regularly; a dull blade increases engine load and can cause stalling.

Following the service intervals in the owner’s manual extends engine life and makes every start effortless.

Comparison: Stihl FS 591 R vs Other Professional Trimmers

The FS 591 R offers the highest displacement and power in this class, making it the preferred choice for heavy‑duty clearing. Its weight is comparable, and the starting system is identical across the three models, so the starting procedure you learn here transfers directly to the competitors.

Best Practices for Long‑Term Performance

Adopt these habits to keep your brushcutter starting reliably for years:

• Always use fresh, correctly mixed fuel; avoid ethanol‑blended gasoline above 10 %.
• Store the machine in a dry, ventilated area; moisture corrodes the carburetor and ignition components.
• Run the engine at idle for a minute after each use to burn off residual fuel in the carburetor.
• Keep a spare spark plug and primer bulb in your tool kit for quick field replacements.
• Record service intervals in a logbook; consistent documentation prevents missed maintenance.

These practices reduce downtime and protect your investment.

Common Mistakes to Avoid

Even experienced operators can fall into bad habits. Watch out for these frequent errors:

• Over‑priming: Pressing the primer bulb more than 7 times floods the carburetor, leading to hard starts and fouled plugs.
• Leaving the choke closed after the engine fires: This creates an overly rich mixture, causing the engine to stall.
• Pulling the starter rope at an angle: Side loads wear the recoil spring and can snap the rope.
• Ignoring the air filter: A dirty filter starves the engine, making it seem like a fuel problem.
• Using stale fuel: Fuel older than 30 days loses volatility and gums the carburetor.

Correcting these mistakes is usually as simple as adjusting your routine.

Frequently Asked Questions

How many times should I press the primer bulb?

For a cold start, press the primer bulb 5–7 times until you see fuel fill the bulb. For a warm start, 2–3 presses are sufficient to refresh the fuel in the carburetor.

Why does my FS 591 R flood when I try to start it?

Flooding typically results from leaving the choke closed too long or over‑priming. Move the choke to the half or open position after the first fire, and limit primer presses to the recommended count.

Can I use regular unleaded gasoline without mixing oil?

No. The FS 591 R is a 2‑stroke engine that requires a 50:1 gasoline‑to‑oil mixture. Running straight gasoline will cause severe engine damage within minutes.

How often should I replace the spark plug?

Stihl recommends replacing the spark plug every 100 hours of operation or at the beginning of each cutting season, whichever comes first.

What should I do if the recoil starter rope snaps?

Replace the rope immediately. Inspect the recoil spring for damage; a broken spring will prevent the rope from retracting and must be serviced by a dealer.

Conclusion

Mastering the starting routine for the Stihl FS 591 R is a blend of preparation, technique, and routine maintenance. By following the pre‑start checklist, using the correct choke and primer settings, and pulling the starter rope smoothly, you ensure reliable ignition every time. Regular care—clean air filter, fresh fuel, timely spark plug changes—keeps the engine responsive and extends its service life. Whether you are tackling thick brush or fine trimming, the steps outlined in this guide answer the core question of How to Start a Stihl F591r Weed Eater? and give you the confidence to operate the machine safely and efficiently. Keep this guide handy, respect the safety precautions, and your FS 591 R will remain a dependable partner on every job site.