My old 29-4 has skipped stitches when the work is feeding toward me ever since I've owned it (20 years). After reading this thread I got to thinking about it so I decided to try other needles I tried 135x17 several different sizes no help. It sewed good forward would also skip with work moving from right to left, but not left to right. Today I made a lexan needle plate so I could see exactly what was going on. For some reason the loop was being formed below the hook. I changed to a 135x7 needle, sews perfect in al directions. Tried size 16 with 69 thread great, 92 thread 19 needle good, 138 with a 23 good. I am readly gooing to enjoy useing this machine now. I use it to repair race horse boots and harness parts, and a few human shoes and boots.
Thanks Wiz and Darren B. your post got my mind working in a new direction. problem solved.
Wiz your post about brazing up the feed part was great I nickel plated the bell crank up put about .0015 on it now it will stitch 51/2 per inch on 6oz. Thanks again.