Troubleshooting Overlocker and Coverstitch Sewing Machines: Expert Fixes for Stitching Success

Having issues with your overlocker or coverstitch sewing machine? Whether you're facing skipped stitches, broken threads, or tension problems, this guide will walk you through how to fix the most common problems—quickly and confidently.

At Direct Sewing Machines & Supplies, we help sewers across New Zealand keep their machines running smoothly with expert advice, genuine parts, and trusted brands like Janome, Pfaff, Husqvarna Viking, Brother, Juki, and Singer.

1. Skipped Stitches? Here's What to Check

Skipped stitches on your overlocker or coverstitch machine are usually caused by using the wrong needle, incorrect threading, or poor thread quality.

Make sure you’re using Schmetz ELx705 needles for coverstitch machines and compatible overlockers. Replace the needle regularly—especially if you've been sewing knits or heavy fabrics.

Threading is critical. If one thread is even slightly off, it can throw off the whole stitch. Always re-thread completely, following your manual.

And don’t underestimate the importance of thread quality. Budget threads often lead to tension issues and breakage. Switch to reliable brands like Madeira Aerolock, Madeira Aeroflock, or Coats Astra to keep stitches smooth and secure.

2. Wavy or Puckered Seams? Adjust These Settings

If your seams are rippling or stretching out of shape, your differential feed settings might be off, or your presser foot pressure may need adjusting. These issues are common when working with lightweight or stretchy fabrics.

Increase your differential feed to prevent fabric stretching, or decrease it if your material is puckering. You should also check your presser foot pressure—lighter for delicate fabrics, firmer for thicker seams.

For consistent results, pair proper settings with high-quality, stretch-friendly threads like Aerolock or Aeroflock.

3. Threads Snapping Mid-Sew?

If your thread keeps breaking while you sew, it’s time to take a closer look at both the thread and your machine.

Cheap or brittle threads are one of the most common causes of thread breakage in overlockers and coverstitch machines. Upgrade to Madeira or Coats Astra thread for better strength and flow.

Ensure your machine is threaded correctly with the presser foot up, so tension discs open properly. Also check for burrs or lint in the thread path, needle plate, or tension dials. A good clean can work wonders.

4. Loops Hanging Off the Fabric Edge

If your overlock stitches are hanging off the edge rather than hugging it neatly, check your cutting width and looper tension settings.

Adjust your cutting width so that the stitch wraps around the fabric edge cleanly. Then fine-tune your upper and lower looper tension until the loops are sitting flush with the edge—no more, no less.

5. Fabric Not Feeding Properly?

When fabric gets stuck or drags through the machine, it's often an issue with presser foot pressure, feed dog build-up, or differential feed.

Try increasing presser foot pressure for thick fabrics. Then clean your feed dogs and check that your differential feed is suited to the fabric type. Overlockers and coverstitch machines rely on clean, well-calibrated feed mechanisms for consistent movement.

Bonus Tip: Re-Threading the Right Way

Incorrect threading is the most common root cause of overlocker and coverstitch problems—especially tension issues.

Always thread loopers first, then needles. And make sure your presser foot is raised when threading, so tension discs stay open. One thread out of place can prevent your machine from chaining correctly.

When to Get Your Machine Serviced

If you've followed all the above steps and your machine still isn’t cooperating, it might be time for a tune-up. Our experienced team at Direct Sewing Machines & Supplies offers expert servicing for all major brands.

We also stock a full range of:

• Overlocker and coverstitch machine needles

• Premium thread options from Madeira and Coats

• Replacement parts and accessories for Janome, Brother, Juki, and more

Final Thoughts

Troubleshooting your overlocker or coverstitch machine doesn’t have to be frustrating. With the right needle, clean threading paths, and quality threads like Madeira Aerolock, Madeira Aeroflock, and Coats Astra, you can achieve smooth, professional seams with ease.

Need help? Shop online or book a machine service at Direct Sewing Machines & Supplies—New Zealand’s trusted source for all things sewing.