I've got my 319 running well. The tension on mine was so cruddy - I took it apart and re-did it - no problems. I haven't had any timing problems either. I think they never fooled with it - somebody just tried the needles and gave up on the machine. You never know someone here may really need that link. Please do post it. This has turned out to be a fantastic resource because everybody has been so willing to share!
I did some free motion last night with mine. It did ok until I tried to do 4 layers of denim - broke the needle. With the darning plate, there is not as much room under the foot as there is with my Japanese 15. I'm thinking Candace is right use a spring, drop the feed dogs and go for it with out the darning plate. My machine is using a borrowed motor and the original belt so FM didn't work all that well so far. The old belt wasn't gripping very well. It has some splits in it. Or it could be that I need to tighten it up a bit. Moments of not turning are not fun when you try to FM. I can see where a treadle would be a real good idea with this machine.
I've noticed that when you wind the bobbin, if some of the thread gets off track, it goes around the winder arm - thread gets stuck - kind of a pain. If you leave the thread in the crack the winder doesn't spin so well next time. It takes time to get it un-stuck.