Sounds like you have two questions, since you would not use a walking foot while doing FMQ.
I ahve heard a lot of complaints about aftermarket walking feet not always working as well as people hoped - most were made much later than your machine and were not made for straight stitch machines so the foot does not line up with the feed dogs.
As to the FMQ question, your stitch lenght is 100% determined by how fast YOU are moving the fabric, since you have disabled the feed dogs completely. So if you want larger stitches - move your hands faster in relation to the speed of the machine.
If however you are somehow trying to use the walking foot with your feed dogs covered - they don't work that way. they work with the feed dogs, not instead of the feed dogs.
When I FMQ, I prefer to use a hopping foot, but I know a lot of folks do fine using regular foot and raising the pressure so the foot just barely glides over the fabric.
If you are having a lot of feeding problems, you may have your presser foot PRESSURE too high, loose it up some and see if that helps. Check the walking foot off the machine and see how high up the needle bar needs to go to fully work the foot. It could be that the distance the needle is traveling is not enough to fully lift the foot during it's cycle.
Last edited by Macybaby; 08-30-2017 at 01:59 PM.