GT-200R Echo String Trimmer Coil Troubleshooting (Expert Fix Tips)
How to Troubleshoot Your GT-200R Echo String Trimmer Coil: Expert Fix Tips
If your GT-200R Echo string trimmer is refusing to start, or is running erratically, a faulty ignition coil could very well be the culprit. The coil is the heart of the ignition system, responsible for generating the high-voltage spark needed to ignite the fuel-air mixture. Diagnosing and fixing coil issues can seem daunting, but with the right tools and a systematic approach, it’s a task you can definitely tackle yourself.
Why the Coil Matters: Understanding the Ignition System
The ignition coil’s role is to transform the low-voltage current from the magneto into a high-voltage pulse, typically in the range of 20,000 to 30,000 volts. This pulse is then sent to the spark plug, which creates a spark that ignites the fuel and air mixture within the engine cylinder. Without a properly functioning coil, your trimmer simply won’t run.
I remember one particularly frustrating afternoon when my trimmer kept cutting out in the middle of a big job. After checking everything else, I finally traced it back to a hairline crack in the coil’s insulation. That tiny crack was enough to cause intermittent sparking and a whole lot of wasted time.
Gathering Your Tools and Materials
Before you dive in, make sure you have the necessary tools and materials on hand. This will save you time and frustration later. Here’s what I recommend:
- Screwdrivers: Both flathead and Phillips head screwdrivers of various sizes.
- Socket Set: A small socket set with metric sizes is essential for removing the engine cover and other components.
- Multimeter: A digital multimeter is crucial for testing the coil’s resistance and continuity.
- Spark Plug Wrench: To remove and inspect the spark plug.
- Feeler Gauge: To set the air gap between the coil and the flywheel.
- Small Engine Tester (Optional): This tool can help diagnose ignition problems more quickly.
- New Spark Plug (Optional): It’s always a good idea to have a spare spark plug on hand.
- Replacement Coil (If Necessary): Make sure you get the correct coil for your GT-200R. Check the part number on the old coil or consult your trimmer’s manual.
- Gloves: To protect your hands.
- Safety Glasses: To protect your eyes.
- Clean Rags: For wiping down parts.
- Pen and Paper: To take notes and keep track of where parts go.
- Camera (Phone): Take pictures as you disassemble to aid reassembly.
Safety First: Preparing for the Task
Before you start working on your trimmer, take these safety precautions:
- Disconnect the Spark Plug Wire: This prevents accidental starting of the engine.
- Allow the Engine to Cool: Never work on a hot engine.
- Work in a Well-Ventilated Area: Gasoline fumes can be harmful.
- Wear Safety Glasses and Gloves: This protects your eyes and hands from debris and chemicals.
- Keep a Fire Extinguisher Nearby: Just in case of a fuel spill.
Step 1: Accessing the Ignition Coil
The first step is to gain access to the ignition coil. This usually involves removing the engine cover and any other components that are in the way.
- Remove the Spark Plug Wire: Gently pull the spark plug wire off the spark plug.
- Remove the Engine Cover: Use a screwdriver or socket wrench to remove the screws holding the engine cover in place. The number and location of the screws may vary depending on the specific model of your GT-200R.
- Inspect the Wiring: Once the cover is off, carefully inspect the wiring leading to the coil. Look for any signs of damage, such as frayed wires, loose connections, or corrosion.
I once spent an hour tearing apart an engine, only to find that the problem was a loose wire connection. A little cleaning and tightening, and the trimmer was back in business. It’s always worth starting with the simplest things first.
Step 2: Visual Inspection of the Coil
Once you have access to the coil, give it a thorough visual inspection. Look for any signs of damage, such as cracks, chips, or melted plastic. These can indicate that the coil has overheated or shorted out.
- Check for Cracks: Pay close attention to the coil’s housing. Cracks can allow moisture to enter, causing corrosion and electrical problems.
- Look for Burn Marks: Burn marks or melted plastic are a sign of overheating, which can damage the coil’s internal components.
- Inspect the Wires: Check the wires leading to and from the coil for any signs of damage or corrosion.
- Smell for Burning: A burning smell can indicate that the coil has overheated and may be damaged.
If you see any of these signs of damage, it’s likely that the coil needs to be replaced.
Step 3: Testing the Coil with a Multimeter
If the visual inspection doesn’t reveal any obvious damage, you can use a multimeter to test the coil’s resistance and continuity. This will help you determine whether the coil is functioning properly.
- Set the Multimeter to Ohms (Ω): Select the ohms setting on your multimeter. This is usually indicated by the Ω symbol.
- Test the Primary Resistance: Place one probe of the multimeter on the primary terminal of the coil (the terminal that connects to the low-voltage wiring) and the other probe on the coil’s ground. The primary resistance should be a low value, typically between 0.5 and 3 ohms. Consult your trimmer’s service manual for the specific resistance value for your model.
- Test the Secondary Resistance: Place one probe of the multimeter on the spark plug terminal of the coil and the other probe on the coil’s ground. The secondary resistance should be a higher value, typically between 6,000 and 15,000 ohms. Again, consult your trimmer’s service manual for the specific resistance value.
- Check for Continuity: Set the multimeter to the continuity setting (usually indicated by a sound wave symbol). Place one probe on the coil’s ground and the other probe on the engine’s ground. The multimeter should beep, indicating that there is continuity between the coil and the engine ground.
Interpreting the Results:
- Low Resistance: If the primary or secondary resistance is significantly lower than the specified value, it indicates a short circuit within the coil.
- High Resistance: If the primary or secondary resistance is significantly higher than the specified value, it indicates an open circuit within the coil.
- No Continuity: If there is no continuity between the coil’s ground and the engine ground, it indicates a grounding problem.
If any of these tests fail, it’s likely that the coil needs to be replaced.
Step 4: Checking the Air Gap
The air gap is the distance between the coil and the flywheel. This gap is crucial for the coil to generate the proper voltage. If the air gap is too large or too small, the coil may not function properly.
- Locate the Flywheel: The flywheel is the rotating component that is connected to the engine’s crankshaft.
- Loosen the Coil Mounting Screws: Loosen the screws that hold the coil in place, but don’t remove them completely.
- Insert a Feeler Gauge: Insert a feeler gauge of the correct thickness between the coil and the flywheel. The recommended air gap for the GT-200R is typically between 0.010 and 0.014 inches (0.25 to 0.35 mm). Consult your trimmer’s service manual for the specific air gap value.
- Tighten the Coil Mounting Screws: Once the feeler gauge is in place, tighten the coil mounting screws.
- Remove the Feeler Gauge: Remove the feeler gauge. The coil should now be properly positioned with the correct air gap.
Setting the air gap correctly is critical. I once had a trimmer that ran poorly because the air gap was too wide. The spark was weak, and the engine kept misfiring. After adjusting the air gap, the trimmer ran like new.
Step 5: Inspecting the Spark Plug
While you’re troubleshooting the ignition system, it’s a good idea to inspect the spark plug. A fouled or damaged spark plug can also cause starting problems.
- Remove the Spark Plug: Use a spark plug wrench to remove the spark plug from the engine.
- Inspect the Spark Plug: Look for any signs of damage, such as cracks, chips, or excessive wear. Also, check for fouling, which is a buildup of carbon deposits on the spark plug electrodes.
- Clean the Spark Plug (If Necessary): If the spark plug is fouled, you can try cleaning it with a wire brush or spark plug cleaner.
- Check the Spark Plug Gap: Use a spark plug gap tool to check the gap between the spark plug electrodes. The recommended gap for the GT-200R is typically between 0.025 and 0.030 inches (0.63 to 0.76 mm). Consult your trimmer’s service manual for the specific gap value.
- Replace the Spark Plug (If Necessary): If the spark plug is damaged or excessively worn, it should be replaced.
Even if the spark plug looks okay, it’s a good idea to replace it with a new one. Spark plugs are relatively inexpensive, and a new spark plug can often improve engine performance.
Step 6: Replacing the Ignition Coil (If Necessary)
If you’ve determined that the ignition coil is faulty, you’ll need to replace it.
- Disconnect the Spark Plug Wire: Make sure the spark plug wire is disconnected from the spark plug.
- Remove the Old Coil: Remove the screws or bolts that hold the old coil in place. Disconnect any wires that are connected to the coil.
- Install the New Coil: Install the new coil in the same position as the old coil. Connect any wires that were connected to the old coil.
- Set the Air Gap: Use a feeler gauge to set the air gap between the coil and the flywheel, as described in Step 4.
- Tighten the Coil Mounting Screws: Tighten the screws or bolts that hold the coil in place.
- Connect the Spark Plug Wire: Connect the spark plug wire to the spark plug.
When replacing the coil, be sure to use the correct part number for your GT-200R. Using the wrong coil can damage the engine.
Step 7: Reassembling the Trimmer
Once you’ve replaced the coil (or determined that it’s not the problem), it’s time to reassemble the trimmer.
- Reinstall the Engine Cover: Reinstall the engine cover and secure it with the screws or bolts that you removed earlier.
- Connect the Spark Plug Wire: Connect the spark plug wire to the spark plug.
- Test the Trimmer: Start the trimmer and see if it runs properly.
Common Problems and Solutions
Here are some common problems that can occur with the GT-200R ignition system, along with their solutions:
- Trimmer Won’t Start: This can be caused by a faulty coil, a fouled spark plug, a clogged air filter, or a fuel problem. Check the spark plug for spark, clean or replace the air filter, and check the fuel lines for clogs.
- Trimmer Runs Poorly: This can be caused by a faulty coil, a fouled spark plug, an incorrect air gap, or a carburetor problem. Check the spark plug gap, adjust the air gap, and clean or rebuild the carburetor.
- Trimmer Cuts Out: This can be caused by a faulty coil, a loose wire connection, or a fuel problem. Check the wiring connections and fuel lines for clogs.
Maintaining Your GT-200R Ignition System
To keep your GT-200R running smoothly, it’s important to maintain the ignition system properly. Here are some tips:
- Replace the Spark Plug Regularly: Replace the spark plug every year or after 100 hours of use, whichever comes first.
- Clean the Air Filter Regularly: Clean the air filter every month or after 25 hours of use.
- Check the Air Gap Regularly: Check the air gap between the coil and the flywheel every year.
- Store the Trimmer Properly: Store the trimmer in a dry place to prevent corrosion.
Advanced Troubleshooting Techniques
If you’ve tried all of the above steps and your trimmer still isn’t running properly, you may need to use some advanced troubleshooting techniques. These techniques require specialized tools and knowledge, so they may be best left to a qualified mechanic.
- Using a Spark Tester: A spark tester can be used to check the strength of the spark produced by the coil.
- Using an Oscilloscope: An oscilloscope can be used to analyze the waveform of the voltage produced by the coil.
- Checking the Magneto: The magneto is the component that generates the electricity that powers the coil. If the magneto is faulty, it can prevent the coil from functioning properly.
Real-World Case Studies
Let me share a couple of real-world examples from my own experience:
- Case Study 1: The Intermittent Spark: A customer brought in a GT-200R that would start sometimes, but then die after a few minutes. I checked the coil resistance, and it seemed okay. However, after running the trimmer for a while, I noticed that the spark would occasionally disappear. I replaced the coil, and the problem was solved. The coil was likely breaking down under heat.
- Case Study 2: The Flooded Engine: Another customer complained that his trimmer wouldn’t start after he accidentally flooded the engine. I removed the spark plug and found that it was soaked in gasoline. I dried the spark plug, cleaned the cylinder, and reinstalled the spark plug. The trimmer started right up.
Finding Replacement Parts
If you need to replace the coil or any other parts, you can find them at your local lawn and garden store or online. Be sure to use the correct part number for your GT-200R.
Here are some online retailers that sell replacement parts for the GT-200R:
- Amazon: Amazon.com
- eBay: eBay.com
- RepairClinic: RepairClinic.com
Conclusion: Getting Your Trimmer Back in Action
Troubleshooting the ignition coil on your GT-200R Echo string trimmer can be a challenging but rewarding task. By following the steps outlined in this guide, you can diagnose and fix most coil problems yourself. Remember to always prioritize safety, use the correct tools, and consult your trimmer’s service manual for specific instructions and specifications. With a little patience and effort, you can get your trimmer back in action and keep your yard looking its best.
My final thought: don’t underestimate the power of a good, clean connection. Often, a simple cleaning and tightening of the wires can save you the cost of a new coil. And remember, taking your time and being methodical is key to successful troubleshooting. Good luck, and happy trimming!
