Hey, I realize this thread hasn't been active in a while, but I think I'm dealing with the same issue and the same machine as @CustomDoug...My stitches are shorter in reverse than when going forward. It's not massively off, but enough to make a messy backstitch. The machine is a Consew 227R-2. I followed @Uwe's video on adjusting the needle and feed dog (which was excellent!) but just like Doug it didn't fix my issue.
Here's a photo of the stitches - forward on top and backwards on the bottom:
I also used Uwe's awesome stitch length gauge. It looks like forward is just a hair under 4mm and reverse is a hair under 3.5mm.
@CustomDoug did you ever get it sorted out?
Does anyone else have other recommendations?
It may be useful to know that a few days ago I had a jam that threw off the hook timing. It took me hours to figure out but I got it back in sync, many thanks to these forums and @Uwe's videos!