Coil For Weed Eater Troubleshooting (3 Pro Fixes Explained)

In the United States alone, over 23 million households use wood as a primary or secondary heating source, highlighting the enduring importance of efficient weed eaters (string trimmers) for maintaining properties and collecting firewood. But what happens when your weed eater suddenly sputters and dies? Often, the culprit is a faulty coil. Don’t throw that weed eater away just yet! I’m here to guide you through troubleshooting and fixing that troublesome coil.

Coil for Weed Eater Troubleshooting: 3 Pro Fixes Explained

As someone who’s spent years felling trees, processing timber, and preparing firewood, I know the frustration of dealing with malfunctioning equipment. Time is money, and a broken weed eater can throw a wrench into your entire schedule. Over the years, I’ve learned that many common weed eater problems, particularly those related to starting and running, often stem from a faulty ignition coil. This guide will walk you through diagnosing and fixing your weed eater coil, saving you time, money, and a trip to the repair shop. Let’s dive in!

Understanding the Ignition Coil: The Heart of Your Weed Eater

Before we get our hands dirty, let’s understand what the ignition coil actually does. Think of it as the heart of your weed eater’s ignition system. Its job is to take the low-voltage electricity from the magneto (a small generator powered by the engine) and transform it into a high-voltage spark. This spark jumps across the spark plug gap, igniting the air-fuel mixture in the cylinder and starting the engine.

A faulty coil can manifest in several ways:

No Spark: The engine won’t start at all. This is the most common symptom.
Weak Spark: The engine starts but runs poorly, sputters, or stalls easily.
Intermittent Spark: The engine runs fine sometimes, but stalls unexpectedly at other times.

If you’re experiencing any of these problems, the coil is a prime suspect.

Pro Fix #1: Testing the Ignition Coil: Is It Really the Problem?

Before you spend money on a new coil, let’s make sure the old one is truly the issue. This is where a multimeter comes in handy. If you don’t have one, they’re relatively inexpensive and a valuable tool for any DIYer. I recommend a digital multimeter for ease of use and accurate readings. You can find a decent one for around $20-$30.

Step 1: Gather Your Tools

You’ll need:

A multimeter (digital is preferred)
A screwdriver (usually a flathead)
A socket wrench or nut driver (to remove the coil cover)
The weed eater itself (obviously!)
Safety glasses and gloves (for protection)

Step 2: Safety First

Disconnect the spark plug wire: This is crucial to prevent accidental starting. Pull the spark plug boot straight off the spark plug. Don’t pull on the wire itself, as you could damage it.
Let the engine cool down: If you’ve been running the weed eater, allow the engine to cool completely before working on it.
Work in a well-ventilated area: Gasoline fumes are flammable and harmful to breathe.

Step 3: Locate the Ignition Coil

The ignition coil is usually located near the flywheel (the spinning metal disc at the front of the engine). It’s often a small, rectangular component with wires leading to the spark plug and the magneto. It is typically encased in a plastic housing. You may need to remove a plastic cover to access it. Refer to your weed eater’s owner’s manual for the exact location if you’re unsure.

Step 4: Visual Inspection

Before using the multimeter, give the coil a thorough visual inspection. Look for:

Cracks or breaks in the coil housing: These can indicate physical damage that could affect performance.
Corrosion on the terminals: Corrosion can impede electrical conductivity.
Loose or frayed wires: These can cause intermittent connection problems.
Burnt or melted plastic: This is a sign of overheating, which can damage the coil.

If you see any of these issues, the coil is likely faulty and needs to be replaced.

Step 5: Performing the Resistance Test

This test will measure the resistance of the coil’s windings. A reading outside the specified range indicates a problem.

Set your multimeter to the Ohms setting (Ω). You’ll usually need to select the appropriate range (e.g., 200Ω, 2kΩ, or 20kΩ). Refer to your multimeter’s manual for instructions.
Locate the two terminals on the coil. One terminal usually connects to the spark plug wire, and the other connects to the magneto.
Touch one probe of the multimeter to each terminal. Make sure the probes are making good contact with the terminals.
Read the resistance value on the multimeter.

Interpreting the Results:

The acceptable resistance range varies depending on the weed eater model and coil type. You’ll need to consult your weed eater’s service manual or the coil manufacturer’s specifications to determine the correct range. However, here are some general guidelines:

Primary winding resistance (low voltage side): Typically, this should be between 0.5 and 5 ohms.
Secondary winding resistance (high voltage side): This should be significantly higher, usually between 2,000 and 15,000 ohms.

If the resistance reading is significantly outside these ranges (e.g., zero ohms or infinite resistance), the coil is likely faulty and needs to be replaced.

Important Note: Some multimeters have an “OL” (Overload) display when the resistance is too high. This indicates infinite resistance, which usually means a broken winding inside the coil.

Step 6: Performing the Air Gap Test

The air gap is the distance between the coil and the flywheel. If the air gap is too large or too small, the coil won’t generate enough spark.

Locate the air gap adjustment screws. These are usually located on the coil mounting bracket.
Loosen the adjustment screws slightly. Just enough to allow the coil to move.
Use a business card or a feeler gauge to set the air gap. The recommended air gap is usually between 0.010 and 0.015 inches (0.25 to 0.38 mm). Slide the business card or feeler gauge between the coil and the flywheel.
Tighten the adjustment screws. Make sure the coil is securely in place.
Remove the business card or feeler gauge.

Real-World Example: The Case of the Stubborn Stihl

I once spent an entire afternoon wrestling with a Stihl FS 90R that refused to start. I checked the fuel, the spark plug, the air filter – everything seemed fine. Finally, I tested the coil and found that the primary winding resistance was off the charts. After replacing the coil and setting the air gap correctly, the weed eater fired up on the first pull. It was a humbling reminder that even experienced professionals can sometimes overlook the obvious.

Pro Fix #2: Replacing the Ignition Coil: A Step-by-Step Guide

If the resistance test indicates a faulty coil, it’s time to replace it. Don’t worry, this is a relatively straightforward process that most DIYers can handle.

Step 1: Purchase a Replacement Coil

Make sure you get the correct replacement coil for your weed eater model. The easiest way to do this is to check your owner’s manual or search online using the weed eater’s model number. You can also take the old coil to a local small engine repair shop and have them match it up.

Where to Buy:

Local Small Engine Repair Shops: These shops often carry a variety of coils and can provide expert advice.
Online Retailers: Amazon, eBay, and other online retailers offer a wide selection of coils at competitive prices.
Manufacturer’s Website: You can usually purchase replacement parts directly from the weed eater manufacturer’s website.

Step 2: Gather Your Tools

You’ll need the same tools as before, plus:

The new ignition coil
A torque wrench (optional, but recommended for tightening screws to the correct torque)

Step 3: Remove the Old Coil

Disconnect the spark plug wire.
Remove the coil cover (if applicable).
Disconnect the wires from the old coil. Pay attention to which wire goes where. You can take a picture with your phone to help you remember.
Remove the coil mounting screws.
Remove the old coil.

Step 4: Install the New Coil

Position the new coil in place.
Install the coil mounting screws. Tighten them to the manufacturer’s specified torque (if available). If you don’t have a torque wrench, tighten them snugly, but don’t overtighten them.
Connect the wires to the new coil. Make sure you connect them in the correct order. Refer to the picture you took earlier if needed.
Set the air gap. Use a business card or feeler gauge to set the air gap between the coil and the flywheel.
Tighten the air gap adjustment screws.
Reinstall the coil cover (if applicable).
Reconnect the spark plug wire.

Step 5: Test the Weed Eater

Start the weed eater and see if it runs properly. If it starts and runs smoothly, you’ve successfully replaced the coil! If it still doesn’t start or runs poorly, double-check your wiring and air gap.

Cost Considerations

The cost of a replacement coil can vary depending on the weed eater model and the brand of the coil. Generally, you can expect to pay between $15 and $50 for a replacement coil. This is significantly cheaper than taking the weed eater to a repair shop, where you could easily spend $100 or more.

Pro Fix #3: Cleaning and Maintaining the Ignition System: Prevention is Key

Even with a new coil, proper maintenance is crucial to prevent future problems. Here are some tips for keeping your weed eater’s ignition system in top shape:

Keeping Things Clean

Regularly clean the spark plug: A dirty spark plug can weaken the spark and make it harder to start the engine. Clean the spark plug with a wire brush and check the gap. Adjust the gap if necessary.
Keep the cooling fins clean: The cooling fins on the engine help to dissipate heat. If they’re clogged with dirt and debris, the engine can overheat and damage the coil. Use a brush or compressed air to clean the cooling fins regularly.
Use fresh fuel: Old fuel can degrade and leave deposits in the carburetor and fuel lines, which can affect engine performance. Use fresh fuel and a fuel stabilizer to prevent fuel degradation. I’ve found that using premium fuel, even if not strictly required, tends to result in cleaner burning and less carbon buildup over time.
Check the spark plug wire: Make sure the spark plug wire is in good condition and securely connected to the spark plug. A loose or damaged spark plug wire can cause intermittent spark problems.

Storage Matters

Store the weed eater properly: When storing the weed eater for an extended period, drain the fuel tank and run the engine until it stalls. This will prevent fuel from sitting in the carburetor and fuel lines and causing problems. You can also use a fuel stabilizer to protect the fuel system.
Protect the coil from moisture: Moisture can damage the coil and cause corrosion. Store the weed eater in a dry place.

Case Study: The Power of Prevention

I once worked with a small logging operation that was constantly plagued by weed eater problems. They were using cheap fuel, neglecting maintenance, and storing their equipment outdoors in the rain. As a result, they were constantly replacing coils, spark plugs, and carburetors.

I implemented a simple maintenance program that included using fresh fuel, cleaning the spark plugs regularly, and storing the equipment indoors. Within a few months, the number of weed eater breakdowns had plummeted. The operation saved hundreds of dollars in repair costs and lost productivity.

Understanding Firewood Seasoning: A Tangential, Yet Crucial, Consideration

While we’re talking about weed eaters and wood processing, it’s worth touching on the importance of proper firewood seasoning. After all, a well-maintained weed eater can help you gather firewood more efficiently.

Green Wood vs. Seasoned Wood:

Green wood is freshly cut wood that has a high moisture content (typically 50% or higher). It’s difficult to burn, produces a lot of smoke, and releases less heat.
Seasoned wood has been allowed to dry for several months, reducing its moisture content to 20% or less. It burns easily, produces less smoke, and releases more heat.

Why Season Firewood?

Improved Burning Efficiency: Seasoned wood burns hotter and more efficiently, providing more heat for your home.
Reduced Smoke and Creosote Buildup: Seasoned wood produces less smoke, which reduces the risk of creosote buildup in your chimney. Creosote is a flammable substance that can cause chimney fires.
Easier to Start: Seasoned wood is much easier to start than green wood.

How to Season Firewood:

Split the wood: Splitting the wood exposes more surface area, which speeds up the drying process.
Stack the wood: Stack the wood in a single row, with gaps between the logs to allow for air circulation.
Elevate the wood: Elevate the wood off the ground to prevent moisture from wicking up into the logs. You can use pallets or scrap lumber to elevate the wood.
Cover the top of the stack: Cover the top of the stack with a tarp or sheet of metal to protect the wood from rain and snow. Leave the sides of the stack uncovered to allow for air circulation.
Allow the wood to dry for at least six months: The drying time will vary depending on the wood species, climate, and stacking method. Hardwoods like oak and maple typically take longer to season than softwoods like pine and fir.

Data Point: Studies have shown that properly seasoned firewood can release up to 25% more heat than green wood.

Personal Anecdote: I remember one winter when I was forced to burn green wood because I hadn’t properly seasoned my firewood supply. The wood was difficult to start, produced a lot of smoke, and barely heated my home. It was a miserable experience, and I learned my lesson about the importance of proper firewood seasoning.

Choosing the Right Tools: Chainsaws vs. Axes

Speaking of firewood, let’s briefly discuss the age-old debate: chainsaws vs. axes. Both tools have their advantages and disadvantages, depending on the task at hand.

Chainsaws:

Pros:
- Faster and more efficient for felling trees and bucking logs.
- Require less physical effort than axes.
- Can handle larger diameter logs.
Cons:
- More expensive than axes.
- Require more maintenance.
- Can be dangerous if not used properly.
- Noisier than axes.

Axes:

Pros:
- Less expensive than chainsaws.
- Require less maintenance.
- Safer than chainsaws (when used properly).
- Quieter than chainsaws.
- Can be used for splitting firewood.
Cons:
- Slower and less efficient for felling trees and bucking logs.
- Require more physical effort than chainsaws.
- Limited to smaller diameter logs.

My Recommendation:

For felling trees and bucking large logs, a chainsaw is the clear winner. However, for splitting firewood and performing other small tasks, an axe can be a valuable tool. I recommend having both tools on hand.

Tool Selection Insights:

Chainsaw Size: Choose a chainsaw with a bar length that is appropriate for the size of the trees you will be felling. A longer bar is needed for larger trees.
Axe Weight: Choose an axe with a weight that you can comfortably swing for extended periods. A heavier axe will split wood more easily, but it will also be more tiring to use.
Safety Gear: Always wear appropriate safety gear when using a chainsaw or axe, including safety glasses, hearing protection, gloves, and chaps.

Troubleshooting Common Weed Eater Problems (Beyond the Coil)

While the coil is a common culprit, other issues can cause your weed eater to malfunction. Here’s a quick rundown of some other potential problems and how to fix them:

Clogged Carburetor: This is a very common issue, especially if the weed eater has been sitting for a while. The carburetor mixes air and fuel, and if it gets clogged with old fuel or debris, the engine won’t run properly. Clean the carburetor with carburetor cleaner. You may need to disassemble the carburetor to clean it thoroughly.
Dirty Air Filter: A dirty air filter restricts airflow to the engine, which can cause it to run poorly. Clean or replace the air filter regularly.
Fuel Problems: Make sure you’re using fresh fuel and that the fuel lines are not cracked or clogged. Also, check the fuel filter to make sure it’s clean.
Spark Plug Issues: A fouled or worn spark plug can cause starting problems or poor engine performance. Clean or replace the spark plug.
Exhaust Problems: A clogged exhaust port or muffler can restrict exhaust flow, which can cause the engine to overheat and run poorly. Clean the exhaust port and muffler.

The Global Landscape of Wood Processing: Challenges and Opportunities

The wood processing and firewood preparation industries face a variety of challenges globally. These include:

Sustainability Concerns: Deforestation and unsustainable logging practices are major environmental concerns. It’s important to source wood from sustainably managed forests.
Safety Regulations: Logging and wood processing are inherently dangerous activities. Strict safety regulations are needed to protect workers.
Economic Factors: Fluctuations in timber prices and fuel costs can impact the profitability of wood processing operations.
Climate Change: Climate change is affecting forest health and productivity, which can impact the availability of timber resources.

However, there are also opportunities for innovation and growth in the wood processing industry. These include:

Improved Logging Techniques: New logging techniques are being developed to minimize environmental impact and improve efficiency.
Sustainable Forestry Practices: Sustainable forestry practices are becoming increasingly important to ensure the long-term availability of timber resources.
Value-Added Wood Products: There is growing demand for value-added wood products, such as engineered lumber and wood composites.
Bioenergy: Wood can be used as a renewable energy source, which can help to reduce reliance on fossil fuels.

Next Steps and Additional Resources

Congratulations! You’ve successfully diagnosed and potentially fixed your weed eater coil. You’ve also learned about firewood seasoning, tool selection, and the challenges and opportunities facing the wood processing industry.

Here are some next steps you can take:

Continue to maintain your weed eater regularly: Follow the maintenance tips outlined in this guide to prevent future problems.
Learn more about firewood seasoning: Experiment with different seasoning methods to find what works best for your climate and wood species.
Explore sustainable forestry practices: Learn how to source wood from sustainably managed forests.
Consider investing in additional wood processing tools: A log splitter, chainsaw mill, or other specialized tools can make your wood processing tasks easier and more efficient.

Additional Resources:

Local Small Engine Repair Shops: These shops can provide expert advice and repair services.
Online Forums and Communities: There are many online forums and communities dedicated to wood processing and firewood preparation. These can be a great source of information and support.
Manufacturer’s Websites: Many tool manufacturers offer online resources and tutorials.
Forestry Associations: Forestry associations can provide information on sustainable forestry practices and regulations.

Suppliers of Logging Tools and Drying Equipment:

Stihl: A leading manufacturer of chainsaws and other logging tools.
Husqvarna: Another leading manufacturer of chainsaws and other logging tools.
Northern Tool + Equipment: A retailer of a wide variety of tools and equipment, including logging tools and drying equipment.
Amazon: A large online retailer that offers a wide selection of logging tools and drying equipment.

Remember, wood processing and firewood preparation can be challenging but rewarding activities. With the right knowledge, tools, and techniques, you can enjoy the benefits of a warm home and a sustainable lifestyle. Don’t be afraid to experiment, learn from your mistakes, and most importantly, have fun! Good luck, and happy wood processing!