EE Bota,
My 304 Jinma has stop screws in the lift lever quadrant and the manual calls for setting one so that the lift dos not over extend and cause damage. I've been unable to make much sense of the manual regarding adjusting the feedback and have never ben really completely satisfied with the way the TPH operates. It is okay, just not as fine aof control as I'd really like.
Where are you located in NC? I'm currently in NC and would like to see your 304 and learn what I can from you if we're reasonably close and you'd be willing. I'm in the Durham area for the next couple of months, though I don't know whether I'll be able to travel much after the next two weeks.