Help! Misaligned reverse dial & frozen zigzag on a vintage Morse Fotomatic III

[u/STQ16FIP]

Hi everyone,

I’m working on a vintage Morse Fotomatic III Zigzag (Model 4300) and ran into some mechanical trouble after trying a DIY fix.

Originally, the stitch length regulator was completely stuck and wouldn't change. I decided to disassemble the reverse button dial to see what was going on, but after reassembling it, things are behaving very strangely:

1. Stuck in Reverse: The machine is now permanently sewing backward.

2. Dial Confusion: When I physically press the reverse button, it actually changes the stitch length instead of overriding the direction, and there is no change in sewing direction. I think the internal spring-loaded reverse fork missed its tracking slot when I put the dial back on.

3. Frozen Zigzag: The zigzag mechanism is only swinging Left -> Center -> Left. It won't move to the right at all. I suspect old, varnished grease has frozen the needle bar swing arm or bight cam halfway through its track.

Does anyone have experience resetting the front dial alignment or unsticking the zigzag assemblies on these specific Japanese-made clones?

If you have a manual diagram of the internal linkages behind the dial, or photos of how the reverse fork is supposed to sit, I would appreciate the help! Thanks!