i have a jinma 254 bought it new few months back used it for the first time yesterday prior to that i changed all fluids but have not flushed and rechanged trans or hydraulic fluid.so yesterday i was playing around with new boxblade just getting a feel for everything and everything seemed ok, then today i was using box blade to smooth my driveway out and i noticed that i couldnt raise the box blade unless i gave it gas. I know if you give it gas it usually goes up faster but if i dont give it gas it will actual fall down when i try to raise it. yesterday it worked fine at any speed any suggestions??