A skipped stitch is a missing connection between the needle thread and bobbin thread. It can leave an unusually long span of thread across otherwise regular needle holes. That is different from short stitches, crooked feeding, or a loose loop underneath. Identify which defect you actually have before turning a tension dial: several problems look similar from the finished side but require different corrections.
Use scrap from the same hide, including the actual number of layers and any lining. A machine that stitches two flat offcuts successfully may still skip at the folded junction that matters. Mark the troublesome location on the sample and keep it beside your next test. Comparing named samples is far more informative than repeatedly sewing across the same damaged strip.
First determine where the skips happen
Look for a pattern. Skips throughout a straight seam suggest a different starting point from a single missed stitch at a bulky crossing. Trouble only in reverse deserves its own test. Trouble on soft, stretchy leather but not firmer leather points toward material movement or needle choice. A fault that began immediately after changing the needle makes installation the first suspect.
Write down the needle package designation, size, thread, material stack, and direction of sewing. These details prevent a common diagnostic mistake: replacing a needle with another of the same incorrect system. Our leather sewing machine needle guide explains why the system designation must be established before size or point style.
Eliminate the needle as an unknown
Switch off and disconnect the machine before replacing the needle. Use a new needle of the system specified for the exact model. Seat it fully and orient it according to that machine's manual. Do not transfer the flat-side direction from a household machine to an industrial machine; installation conventions differ. Tighten the clamp as directed, without improvising extra leverage.
A needle that looks straight can still have a damaged point or a slight bend. Replacing it is usually a more useful test than trying to judge it by eye. Keep the removed needle separate so it does not find its way back into your supplies. If the new needle strikes anything during the manufacturer's permitted handwheel check, stop before powering the machine.
Needle size must also work with the thread. A thread that crowds the eye or rubs heavily through it introduces another variable. Increasing needle size is not automatically the answer, because larger holes can spoil the leather and the machine has a supported range. Use needle size selection to frame the choice, then confirm against the machine documentation.
Reestablish a known threading path
Remove the upper thread and thread the machine again from the beginning, following its diagram. Check each guide and the take-up lever rather than simply pulling the existing thread taut. Seat the bobbin correctly and confirm that its thread follows the specified path. Do not immediately change upper and lower tension together: that removes your baseline without proving the original cause.
If the machine recently sewed well, restore the last documented working setup on a fresh sample. This is particularly helpful after switching from textile work to leather. The threading guide helps organize the checks, but the model's own diagram remains the authority for direction and sequence. Different machines can put apparently similar guides in different positions.
Watch what happens at the difficult section
Observe the material from a comfortable distance while sewing slowly. Does it rise with the needle? Does a bulky seam tip the foot? Is the project hanging off the table and pulling sideways? Support the project so its weight does not steer it. Guide its direction without pushing or pulling against the machine's feed.
A skip at a thickness transition may be a seam-design or support problem rather than a timing problem. Test the same stack without the abrupt transition, then recreate the transition separately. If only the junction fails, consider reducing bulk through suitable construction changes. The leather thickness guide distinguishes seam thickness from the misleading assumption that anything fitting under the foot is sewable.
Compare forward and reverse separately
Sew a short forward line on fresh material, stop, and inspect both sides. Then test reverse according to the machine instructions. If forward sewing is clean but reverse produces skips, preserve that comparison for a technician. Avoid compensating by sewing multiple reverse passes over a weak section; extra holes may make the seam harder to repair.
Our reverse stitching guide discusses seam endings and why reverse feeding deserves its own sample. A satisfactory test includes the actual stitch length and thread you will use, not merely a setting that happens to stop the skips on a different material. Recheck corners too if they are part of the intended project.
When further adjustment belongs with service
Contact a qualified technician when correct installation, fresh consumables, careful threading, and supported material do not resolve the problem. Stop sooner if there is striking, unusual resistance, a recent needle collision, or visible damage around the needle opening. Supply the failed and successful samples, plus the setup notes. That gives the technician evidence instead of a vague report that the machine dislikes leather.
Do not loosen hook, needle-bar, or feed timing components based on a generic video. Those relationships are model-specific, and a skipped stitch alone does not prove timing is wrong. A reliable repair ends with a repeatable seam on the intended material stack, including starts, crossings, and reverse if used. Keep that successful sample and its settings as your next troubleshooting baseline.