McCulloch MWT420 Spare Parts List
![McCulloch MWT420 manual cover](/images/VmrtUMxxwZkRtjBLpGGiuRXY/thumbs/thumb175x175.webp)
To start the McCulloch MWT420 Trimmer, prime the engine by pressing the primer bulb several times, set the choke to 'start', and pull the starter rope firmly until the engine fires. Once the engine starts, move the choke to the 'run' position.
To replace the trimmer line, first turn off the trimmer and disconnect the spark plug. Remove the spool cap, take out the old line, and insert the new line following the directional arrows marked on the spool. Wrap the line evenly and secure it before reattaching the cap.
If the trimmer won't start, check the fuel level and quality, ensure the spark plug is clean and properly connected, and inspect the air filter. If issues persist, consult the user manual for further troubleshooting steps.
Regular maintenance should be performed after every 25 hours of use or at the beginning of each season. This includes checking the air filter, spark plug, fuel lines, and cleaning the trimmer head.
The McCulloch MWT420 Trimmer requires unleaded gasoline with a minimum octane rating of 90, mixed with high-quality 2-stroke engine oil at a ratio of 50:1.
Adjusting the carburetor should be done carefully. Locate the adjustment screws on the carburetor and turn them slightly to adjust the idle speed and mixture. It is recommended to refer to the user manual or consult a professional for precise tuning.
Always wear protective gear such as gloves, safety goggles, and ear protection. Ensure the area is clear of bystanders and debris before starting, and follow all operational guidelines to prevent injury.
Excessive vibration can be caused by an unbalanced trimmer head or damaged cutting attachments. Check the trimmer head for wear and replace any damaged parts. Ensure the cutting line is properly installed and balanced.
Remove the air filter cover and take out the filter. Wash it with warm, soapy water and let it dry completely. Reinstall the filter and cover before using the trimmer again.
If the trimmer line breaks frequently, check for obstructions in the cutting path, ensure you are using the correct line diameter, and avoid contact with hard surfaces. Replace with high-quality line if necessary.