I have a 284 LE with the shuttle shift and noticed the cable has an adjustment below the mechanical shifting mechanism. I would think moving it would change the position of the shift lever. My shuttle shift was extremely stiff until I had 15 hours on the tractor, actually sheared the roll pin. I installed a 10mm bolt and nylock nut in its place and haven't had anymore problems the it since.
The fellow I bought from (Andy Weeks at Triple DDD) sells grey market and new Jinma (AgKing) tractors and he told me that the price of the Jinma has shut down his grey market business. The greys are 15-20 year old units and you can get a brand new Jinma for the same $ with a warranty. He only sells Koyker loaders and I bought one, the 140 cost me $2750 and I really like it so far. It is a quick attach but I really doubt I ever take it off, it has saved my back so much already that I can't imagine not having it on the tractor. Anything you need to move or lift and it's right there ready to work. I can't comment on the Chinese version, I've never seen one.
Anyone telling you that these tractors are worthless junk haven't run one, they are tough little machines and I feel worth every penny. The paint isn't perfect but hey, it's a tractor and if you work it it isn't going to be beautiful long anyway. Save some money, buy from a good dealer, and put the rascal to work. I've always wanted a CUT and now I have one, wish I would have started this many years ago.
John, Greg, and Chip can help you through the rough spots you might hit (they certainly have with me anyway) and I think you will, like me- be happy with a Jinma.
Best of luck to you on what ever you get.
Bill