Introduction
Restringing a Craftsman bump weed eater is a routine maintenance task that keeps your trimmer cutting cleanly and extends the life of the bump head. Whether you are a seasoned landscaper or a weekend gardener, knowing how to restring a Craftsman bump weed eater ensures you spend less time fighting tangled line and more time trimming. This guide walks you through every step, from understanding the bump‑feed mechanism to selecting the right trimmer line, and it includes practical tips, common mistakes to avoid, and a handy comparison table for line types. By the end you will feel confident tackling the job yourself and keeping your equipment in top shape.
- Understanding the Bump Head Mechanism
- Tools and Materials Needed
- Safety Precautions
- Step‑by‑Step Guide to Restringing
- Choosing the Right Trimmer Line
- Tips for Optimal Performance
- Common Mistakes and How to Avoid Them
- Maintenance After Restringing
- Troubleshooting Common Issues
- Frequently Asked Questions
- Conclusion
Understanding the Bump Head Mechanism
The bump head on a Craftsman weed eater uses a spring‑loaded spool that releases line each time you tap the head against the ground. Inside the housing, a centrifugal clutch engages the spool when the engine reaches operating speed, allowing the line to feed outward. When you “bump” the head, a small lever pushes the spool forward, releasing a measured length of line. This design eliminates the need for manual line advances and provides a consistent cutting width. Knowing how the spring, spool, and lever interact helps you diagnose feeding problems and ensures you reinstall the line in the correct direction.
Most Craftsman bump heads are labeled with an arrow indicating the winding direction. Winding the line opposite to this arrow causes the line to retract instead of feed, leading to frequent jams. The spool typically holds two separate line channels, each feeding one side of the cutting swath. Keeping both channels evenly wound prevents vibration and uneven wear on the trimmer head. Familiarity with these basics makes the restringing process smoother and reduces the chance of damaging the head.
Tools and Materials Needed
Before you begin, gather the following items so you can work without interruptions:
- Replacement trimmer line (matching the diameter recommended for your model, usually .080‑.095 in)
- Scissors or a sharp utility knife for cutting line
- Work gloves to protect your hands from sharp edges
- Safety glasses or goggles
- Flat‑head screwdriver (if your bump head uses a retaining screw)
- Clean rag for wiping debris from the head
- Owner’s manual for model‑specific diagrams
Having the correct line diameter is critical; a line that is too thick will not feed properly, while a line that is too thin may break under load. Check the manual or the label on the bump head for the exact specification. A clean work area and good lighting also help you see the winding direction arrow and any wear on the spool.
Safety Precautions
Safety should always come first when servicing power equipment. Follow these precautions before you start:
- Disconnect the spark plug wire or remove the battery pack to prevent accidental starts.
- Allow the engine to cool completely if it has been running.
- Wear safety glasses to protect your eyes from flying debris or snapped line.
- Use gloves to avoid cuts from the line ends and any sharp metal edges on the head.
- Work on a stable, flat surface and keep the trimmer secured so it cannot roll or tip.
- Never force the spool or lever; if something feels stuck, inspect for damage before applying more pressure.
These steps reduce the risk of injury and protect the trimmer from accidental damage during the restringing process.
Step‑by‑Step Guide to Restringing
Follow these ordered steps to restring your Craftsman bump weed eater correctly: (See Also:How To Replace Blades On Weed Eater)
- Remove the bump head. Locate the retaining knob or screw on the side of the head. Turn it counter‑clockwise (or unscrew) and pull the head assembly off the drive shaft.
- Open the spool. Most Craftsman heads have a two‑piece spool that separates by pressing the release tabs on the side. Gently pull the halves apart to expose the line channels.
- Clean the spool. Use a rag to wipe away grass clippings, dirt, and old line fragments. A clean spool ensures smooth line feeding.
- Cut the new line. Measure two equal lengths of line, typically 10‑12 feet each, depending on the spool capacity. Cut cleanly with scissors or a knife.
- Insert the line into the anchor holes. Feed one end of each line into the designated anchor hole on the spool. Push until the line seats firmly.
- Wind the line following the arrow. Hold the spool steady and wind each line in the direction indicated by the arrow on the spool. Keep tension even and avoid overlapping the turns. Fill each channel to about 80 % capacity to leave room for the bump mechanism to operate.
- Secure the line ends. Tuck the free ends into the retaining slots or notches on the spool so they do not unwind during reassembly.
- Reassemble the spool. Snap the two spool halves back together, ensuring the release tabs click into place.
- Reattach the bump head. Align the head with the drive shaft, slide it on, and tighten the retaining knob or screw securely.
- Test the feed. Reconnect the spark plug wire or battery, start the engine, and gently tap the head on the ground. The line should advance smoothly. If it does not, repeat the winding step, checking direction and tension.
Taking your time on each step prevents the most common feeding problems and ensures a clean cut every time you use the trimmer.
Choosing the Right Trimmer Line
Trimmer line comes in several shapes and materials, each suited to different cutting conditions. Round line is the most common and works well for general grass and light weeds. Square or star‑shaped line offers sharper edges, increasing cutting efficiency on thicker brush. Twisted line reduces drag and noise, making it a good choice for residential areas. Serrated line adds tiny teeth that slice through tough stems but can wear faster. Matching the line to your typical workload improves performance and reduces the frequency of restringing.
Diameter also matters. Most Craftsman bump heads accept .080‑.095 in line. Thicker line lasts longer but requires more engine power to spin; thinner line feeds easier but may break under heavy load. Consult your owner’s manual for the maximum recommended diameter. Using a line within the specified range keeps the bump head operating as designed and prevents premature wear on the drive shaft.
| Line Type | Best For | Durability | Noise Level | Cutting Efficiency |
|---|---|---|---|---|
| Round | General grass, light weeds | Medium | Low | Good |
| Square / Star | Thick brush, heavy weeds | High | Medium | Excellent |
| Twisted | Residential lawns, noise‑sensitive areas | Medium | Very Low | Good |
| Serrated | Woody stems, tough vegetation | Low‑Medium | Medium | Very High |
Tips for Optimal Performance
- Wind the line tightly and evenly; loose winding causes line to slip and jam.
- Leave a small gap (about 1/8 in) between the wound line and the spool flange to allow the bump lever to move freely.
- Replace both line channels at the same time to maintain balance and reduce vibration.
- Store spare line in a cool, dry place; UV exposure makes line brittle.
- Periodically lubricate the bump head’s spring and lever with a light silicone spray to keep the feeding action smooth.
- Inspect the drive shaft splines for wear each time you remove the head; worn splines can cause the head to slip.
- Use the correct line diameter; oversized line stresses the motor and can damage the clutch.
Applying these tips consistently will extend the interval between restringings and keep your Craftsman weed eater running at peak efficiency.
Common Mistakes and How to Avoid Them
- Winding the line in the wrong direction. Always follow the arrow on the spool; reversing direction makes the line retract instead of feed.
- Overfilling the spool. Packing the channels to capacity prevents the bump lever from moving, leading to a stuck head. Fill to roughly 80 %.
- Using mismatched line diameters. Mixing .080 in and .095 in line creates uneven feed and vibration. Stick to a single diameter per job.
- Neglecting to clean the spool. Debris buildup interferes with line release and can cause the spring to bind.
- Forcing the head onto the shaft. If the head does not slide on easily, check for damaged splines or a bent shaft rather than applying force.
- Skipping the test bump. Always test the feed after reassembly; catching a problem early saves time later.
Awareness of these pitfalls helps you complete the job right the first time and avoids unnecessary wear on the trimmer.
Maintenance After Restringing
After you have successfully restrung the bump head, a few simple maintenance steps keep the trimmer in good condition. First, wipe down the exterior of the head and shaft to remove any grass sap or dirt that could accelerate corrosion. Check the air filter and clean or replace it if it appears clogged; a clean filter ensures the engine delivers consistent power to the cutting head. Lubricate the drive shaft splines with a light grease recommended by Craftsman to reduce friction during operation. Finally, run the trimmer for a minute at idle, then engage the throttle and perform a few test cuts. Listen for unusual noises such as rattling or grinding, which could indicate a misaligned spool or worn bearings. Addressing these early prevents larger repairs down the road.
Troubleshooting Common Issues
Even with careful restringing, you may encounter a few typical problems. If the line does not advance when you bump the head, verify that the line is wound in the correct direction and that the spool is not overfilled. A line that breaks immediately often indicates a diameter that is too thin for the workload or a nick in the line caused by a rough spool edge; inspect the spool for burrs and smooth them with fine sandpaper. Excessive vibration usually means the two channels are unevenly wound; rewind both channels to the same length and tension. If the head spins but the line stays retracted, the bump lever spring may be weakened; replace the spring assembly if it shows signs of fatigue. Lastly, a burning smell from the motor suggests the line is too thick, causing the engine to overload; switch to the recommended diameter. (See Also:How To Feed Line On Milwaukee Weed Eater)
Frequently Asked Questions
How often should I restring my Craftsman bump weed eater?
Restring whenever the line wears down to less than 2 inches or when you notice reduced cutting performance. For typical residential use, this may be every 3‑5 hours of operation.
Can I use any brand of trimmer line?
Yes, as long as the line matches the diameter and shape recommended for your model. Using a reputable brand ensures consistent quality and reduces breakage.
Why does the line keep jamming after I bump the head?
Jamming is usually caused by winding the line opposite the arrow, overfilling the spool, or debris inside the head. Re‑wind following the arrow, leave space in the channels, and clean the spool thoroughly.
Do I need to replace the bump head spring regularly?
The spring lasts many seasons, but if the line fails to feed after repeated bumps, the spring may be fatigued. Inspect it during each restringing and replace if it feels weak or shows corrosion. (See Also:How To Reload A Milwaukee Weed Eater)
Is it safe to restring with the engine running?
Never restring while the engine is running. Always disconnect the spark plug wire or remove the battery pack to prevent accidental start‑up and serious injury.
Conclusion
Learning how to restring a Craftsman bump weed eater empowers you to maintain your trimmer efficiently and keep your lawn looking sharp. By understanding the bump‑feed mechanism, gathering the right tools, following the step‑by‑step process, and selecting the appropriate line type, you can avoid common pitfalls and extend the life of your equipment. Regular maintenance after each restringing, combined with the practical tips and troubleshooting advice outlined here, ensures reliable performance season after season. With a little practice, the task becomes quick and routine, letting you focus on the real work—creating a clean, well‑trimmed landscape.