New to sewing machines and am using a techsew 2750. Having a bear of a time dialing it in. Anyhow as you can see in the photos the stitch looks nice on top ( red ) but the bottom (white) looks like the top tension is not tight enough but it is so tight it is hard to pull the material out of the machine. I have adjusted the bobbin tension like as seen in YouTube videos so I don't think that is to blame. I threaded it following the Techsew video ( that slightly differs from the manual ). I am currently using a diamond point needle size #19 and MBT thread size #5. The other issue you can see is the backstitch look like crap and isn't going back into the same holes. When I backstitch, I come to a stop, engage the backstitch lever and run the foot pedal. I don't keep the machine running and slam down the lever like someone who has been doing this for years.
Thanks in advance for your time.