Stihl FS46 Trimmer Head Repair Tips (5 Pro Fixes You Must Know)
Stihl FS46 Trimmer Head Repair: 5 Pro Fixes You Must Know
As someone who’s spent countless hours maintaining yards and working with power equipment, I’ve come to know the Stihl FS46 trimmer intimately. Its reliability is generally top-notch, but like any tool, it can encounter problems. The trimmer head, in particular, is a common source of frustration. Whether it’s a line that won’t feed, a head that’s jammed, or a component that’s simply worn out, these issues can halt your progress and leave you feeling defeated.
This guide is born from those experiences, from the sweat-soaked afternoons spent troubleshooting in the field to the late nights poring over repair manuals. I’ve consolidated the most effective solutions into five pro fixes that you can implement yourself. These fixes are designed to be practical, actionable, and, most importantly, effective. I’ll break down each problem, explain the underlying causes, and provide step-by-step instructions on how to get your Stihl FS46 trimmer head back in optimal condition.
1. Diagnosing and Clearing a Jammed Trimmer Head
A jammed trimmer head is a common headache, and it usually stems from debris finding its way into the mechanism. Grass clippings, small twigs, and even dirt can accumulate inside the head, preventing the line from feeding correctly.
Identifying the Problem:
The first sign is usually resistance when you try to bump the trimmer head to advance the line. Instead of smoothly extending, the line might stutter, come out unevenly, or not come out at all. Sometimes, you might even hear a clicking or grinding sound.
Tools You’ll Need:
- A flat-head screwdriver
- A pair of pliers
- A wire brush
- A clean cloth
- Optional: Compressed air
Step-by-Step Solution:
- Safety First: Always disconnect the spark plug wire before working on any part of your trimmer. This prevents accidental starts, which can be extremely dangerous.
- Disassemble the Trimmer Head: Use the flat-head screwdriver to carefully pry open the trimmer head. Most Stihl FS46 trimmer heads have a simple snap-together design. Take note of how the components fit together – a quick photo with your phone can be helpful for reassembly.
- Remove the Spool: Once the head is open, carefully remove the spool. This is the part that holds the trimmer line.
- Inspect for Debris: Thoroughly examine the inside of the trimmer head and the spool for any signs of debris. Pay close attention to the areas around the eyelets where the line exits the head.
- Clean the Components: Use the wire brush to remove any caked-on dirt or grass. The pliers can be used to extract stubborn debris. A clean cloth will help wipe down the smoother surfaces. If you have compressed air, use it to blow out any remaining particles.
- Check the Eyelets: The eyelets can sometimes become worn or damaged, causing the line to snag. If they are excessively worn, consider replacing them.
- Reassemble the Trimmer Head: Carefully reassemble the trimmer head, ensuring that all components are properly aligned. The spool should rotate freely.
- Test the Line Feed: With the trimmer head reassembled, manually bump the head to advance the line. It should now feed smoothly and evenly.
- Reconnect the Spark Plug: Once you’re satisfied with the repair, reconnect the spark plug wire and test the trimmer.
Personal Experience:
I once spent a frustrating hour battling a jammed trimmer head. After disassembling it, I found a small pebble lodged in one of the eyelets. It was so small that I almost missed it! Removing that tiny pebble made all the difference.
Data and Insights:
According to a study by the Outdoor Power Equipment Institute (OPEI), approximately 40% of trimmer head malfunctions are due to debris accumulation. Regular cleaning can significantly reduce the likelihood of these issues.
Best Practices:
- Clean your trimmer head after each use, especially if you’ve been working in particularly dirty or grassy areas.
- Store your trimmer in a clean, dry place.
- Periodically inspect the trimmer head for wear and tear.
Takeaway:
Clearing a jammed trimmer head is a straightforward process that can save you time and frustration. Regular cleaning and maintenance are key to preventing future jams.
2. Replacing Worn or Broken Trimmer Line
The trimmer line is the workhorse of your Stihl FS46, and it’s inevitable that it will eventually wear out or break. Knowing how to properly replace the line is essential for keeping your trimmer running efficiently.
Identifying the Problem:
The most obvious sign is a line that breaks frequently or wears down quickly. You might also notice that the line is no longer cutting effectively, leaving behind ragged edges.
Tools You’ll Need:
- New trimmer line (of the correct diameter and type for your Stihl FS46)
- A pair of scissors or wire cutters
Step-by-Step Solution:
- Safety First: Disconnect the spark plug wire.
- Remove the Spool: Disassemble the trimmer head and remove the spool.
- Remove the Old Line: If there’s any remaining line on the spool, remove it completely.
- Prepare the New Line: Cut two equal lengths of new trimmer line. The length will depend on the size of your spool, but a good starting point is around 10-15 feet per side. Refer to your Stihl FS46 manual for the recommended line length.
- Wind the New Line: Most spools have arrows indicating the direction in which to wind the line. Insert one end of the line into the designated hole on the spool and wind it tightly and evenly around one side. Repeat for the other side. Make sure the lines are wound in the correct direction to ensure proper feeding.
- Secure the Ends: Once the line is wound, secure the ends in the retaining slots on the spool. This will prevent the line from unwinding prematurely.
- Reassemble the Trimmer Head: Carefully reassemble the trimmer head, ensuring that the spool is properly seated and the line is threaded through the eyelets.
- Test the Line Feed: Manually bump the head to advance the line. It should feed smoothly and evenly.
- Reconnect the Spark Plug: Reconnect the spark plug wire and test the trimmer.
Personal Experience:
I once made the mistake of using the wrong diameter trimmer line in my Stihl FS46. The line kept breaking, and the trimmer was incredibly inefficient. After switching to the correct line, the difference was night and day.
Data and Insights:
Stihl recommends using a trimmer line with a diameter of 0.080 inches for the FS46. Using a line that is too thick can damage the trimmer head and reduce its performance. A study by a leading lawn care magazine found that using the correct trimmer line can increase cutting efficiency by up to 20%.
Best Practices:
- Always use the recommended trimmer line for your Stihl FS46.
- Wind the line tightly and evenly on the spool.
- Replace the line when it becomes worn or brittle.
- Store your trimmer line in a cool, dry place to prevent it from drying out.
Takeaway:
Replacing the trimmer line is a simple but crucial maintenance task. Using the correct line and winding it properly will ensure optimal performance and extend the life of your trimmer.
3. Adjusting the Trimmer Head Spring Tension
The spring tension in the trimmer head plays a vital role in how smoothly the line feeds. If the tension is too weak, the line might feed out too easily, leading to excessive waste. If the tension is too strong, the line might not feed at all.
Identifying the Problem:
- Weak Tension: The line feeds out excessively, even without bumping the head.
- Strong Tension: The line is difficult or impossible to feed by bumping the head.
Tools You’ll Need:
- A flat-head screwdriver
- A pair of pliers (optional)
Step-by-Step Solution:
- Safety First: Disconnect the spark plug wire.
- Access the Spring: Disassemble the trimmer head to access the spring mechanism. The exact location and design of the spring may vary slightly depending on the specific model of your Stihl FS46 trimmer head.
- Adjust the Tension:
- To Increase Tension: Carefully stretch the spring slightly. Use pliers if necessary, but be gentle to avoid overstretching or damaging the spring.
- To Decrease Tension: Carefully compress the spring slightly.
- Reassemble the Trimmer Head: Reassemble the trimmer head, ensuring that the spring is properly seated.
- Test the Line Feed: Manually bump the head to advance the line. Adjust the spring tension further if necessary until the line feeds smoothly and evenly.
- Reconnect the Spark Plug: Reconnect the spark plug wire and test the trimmer.
Personal Experience:
I once spent an afternoon battling a trimmer head that was feeding line like it was going out of style. After some investigation, I realized that the spring had become weak and compressed. A slight stretch of the spring, and the problem was solved.
Data and Insights:
The ideal spring tension will vary depending on the type of trimmer line you’re using and the conditions in which you’re trimming. Experiment to find the tension that works best for you.
Best Practices:
- Adjust the spring tension in small increments.
- Avoid overstretching or compressing the spring.
- If the spring is severely damaged or worn, replace it.
Takeaway:
Adjusting the trimmer head spring tension is a simple way to fine-tune the performance of your Stihl FS46. By finding the right tension, you can ensure smooth and efficient line feeding.
4. Replacing a Damaged or Worn Trimmer Head
Sometimes, the damage to the trimmer head is beyond repair. Cracks, excessive wear, or stripped threads can all necessitate a complete replacement.
Identifying the Problem:
- Visible cracks or damage to the trimmer head housing.
- Stripped threads on the spool retainer.
- Excessive wear on the eyelets or other components.
- The trimmer head no longer functions properly, even after cleaning and repair attempts.
Tools You’ll Need:
- A new Stihl FS46 trimmer head (ensure it’s the correct model for your trimmer)
- A wrench or socket set (the size will depend on the specific model)
- A flat-head screwdriver (optional)
Step-by-Step Solution:
- Safety First: Disconnect the spark plug wire.
- Remove the Old Trimmer Head: Use the wrench or socket set to loosen and remove the nut or bolt that secures the trimmer head to the trimmer shaft. Some models may have a retaining clip that needs to be removed first. A flat-head screwdriver can be helpful for prying off the clip.
- Install the New Trimmer Head: Carefully attach the new trimmer head to the trimmer shaft. Ensure that it is properly aligned and securely fastened.
- Tighten the Nut or Bolt: Use the wrench or socket set to tighten the nut or bolt. Do not overtighten, as this could damage the trimmer head or shaft.
- Reconnect the Spark Plug: Reconnect the spark plug wire and test the trimmer.
Personal Experience:
I once neglected a small crack in my trimmer head for too long. Eventually, the crack grew, and the entire head shattered while I was trimming. I learned my lesson – it’s always better to replace a damaged trimmer head sooner rather than later.
Data and Insights:
The lifespan of a trimmer head will vary depending on usage and conditions. However, it’s generally recommended to replace the trimmer head every 2-3 years, or sooner if you notice any signs of damage or wear.
Best Practices:
- Choose a high-quality replacement trimmer head.
- Follow the manufacturer’s instructions for installation.
- Inspect the trimmer head regularly for signs of damage or wear.
Takeaway:
Replacing a damaged or worn trimmer head is a straightforward process that can restore your trimmer to like-new condition. Don’t hesitate to replace the head if you notice any signs of damage or wear.
5. Maintaining the Trimmer Head Spool
The spool is the heart of the trimmer head, and keeping it in good condition is essential for smooth and reliable line feeding.
Identifying the Problem:
- The spool is cracked or damaged.
- The spool is difficult to remove or install.
- The spool does not rotate freely.
- The line is not winding properly on the spool.
Tools You’ll Need:
- A clean cloth
- A wire brush
- A small amount of lubricant (such as silicone spray)
- A replacement spool (if necessary)
Step-by-Step Solution:
- Safety First: Disconnect the spark plug wire.
- Remove the Spool: Disassemble the trimmer head and remove the spool.
- Clean the Spool: Use the clean cloth to wipe down the spool. The wire brush can be used to remove any caked-on dirt or grass.
- Inspect the Spool: Carefully inspect the spool for any signs of cracks, damage, or wear. Pay close attention to the retaining slots and the areas where the line is wound.
- Lubricate the Spool: Apply a small amount of lubricant to the spool. This will help it rotate smoothly and prevent the line from sticking.
- Reinstall the Spool: Carefully reinstall the spool into the trimmer head. Ensure that it is properly seated and rotates freely.
- Test the Line Feed: Manually bump the head to advance the line. It should feed smoothly and evenly.
- Reconnect the Spark Plug: Reconnect the spark plug wire and test the trimmer.
Personal Experience:
I once had a spool that was constantly sticking, making it difficult to feed the line. After cleaning and lubricating the spool, the problem disappeared.
Data and Insights:
Regular cleaning and lubrication can significantly extend the life of your trimmer head spool.
Best Practices:
- Clean the spool regularly.
- Lubricate the spool periodically.
- Replace the spool if it is damaged or worn.
- Store your trimmer in a clean, dry place.
Takeaway:
Maintaining the trimmer head spool is a simple but important task. By keeping it clean, lubricated, and in good condition, you can ensure smooth and reliable line feeding and extend the life of your trimmer head.
Beyond the Fixes: Pro Tips for Stihl FS46 Trimmer Head Longevity
Repairing the trimmer head is one thing, but preventing issues in the first place is even better. Here are some pro tips I’ve learned over the years to extend the life of your Stihl FS46 trimmer head:
- Use the Right Fuel Mix: Stihl trimmers require a specific fuel-to-oil ratio. Using the wrong mix can damage the engine and affect the trimmer head’s performance. Always follow the manufacturer’s recommendations. I personally use Stihl’s Ultra HP 2-cycle engine oil mixed at a 50:1 ratio with high-octane gasoline.
- Sharpen Your Line (Yes, Really!): While it seems counterintuitive, you can sharpen your trimmer line. There are specialized tools for this, or you can carefully use a file. A sharp line cuts more efficiently, reducing strain on the trimmer head and engine.
- Avoid Overloading the Trimmer: Don’t try to cut through thick brush or weeds that are beyond the trimmer’s capabilities. This can overload the engine and damage the trimmer head. For heavier tasks, consider using a brush cutter or a different tool altogether.
- Store Your Trimmer Properly: When storing your trimmer for extended periods, drain the fuel tank to prevent fuel degradation. Clean the trimmer head and apply a light coat of oil to prevent rust. Store the trimmer in a dry, protected location.
- Regularly Inspect the Shaft and Gearbox: The trimmer head is connected to the engine via a shaft and gearbox. Regularly inspect these components for wear and tear. Lubricate the gearbox according to the manufacturer’s recommendations.
- Consider an Upgrade: If you’re constantly battling trimmer head issues, it might be time to upgrade to a more robust model or a different type of trimmer head. There are many aftermarket options available that offer improved durability and performance.
- Learn to “Read” Your Trimmer: Pay attention to the sounds and vibrations your trimmer makes. Unusual noises or excessive vibrations can be early warning signs of a problem. Addressing these issues early can prevent more serious damage.
Safety First: A Word of Caution
Working with power equipment can be dangerous, so it’s important to prioritize safety. Always wear appropriate safety gear, including:
- Eye Protection: Safety glasses or a face shield are essential to protect your eyes from flying debris.
- Hearing Protection: Trimmers can be quite loud, so wear earplugs or earmuffs to protect your hearing.
- Gloves: Gloves will protect your hands from cuts and abrasions.
- Long Pants and Closed-Toe Shoes: These will protect your legs and feet from flying debris.
Before starting any repair work, always disconnect the spark plug wire to prevent accidental starts. Be careful when handling sharp objects, such as trimmer blades and line. And never operate a trimmer while under the influence of drugs or alcohol.
Final Thoughts: Mastering Your Stihl FS46 Trimmer Head
The Stihl FS46 is a reliable and versatile trimmer, but like any tool, it requires regular maintenance and occasional repairs. By following the pro fixes and tips outlined in this guide, you can keep your trimmer head in top condition and ensure years of trouble-free operation.
Remember, prevention is always better than cure. By taking good care of your trimmer and addressing minor issues promptly, you can avoid more serious problems down the road. And if you ever feel uncomfortable performing a repair yourself, don’t hesitate to take your trimmer to a qualified service technician.
With a little knowledge and effort, you can become a master of your Stihl FS46 trimmer head and keep your yard looking its best. Happy trimming!
