Hmmm... My Kioti workshop manual say 4975 psi.. Our tractor sizes are similiar I would expect something over 4000 PSI. Where and what did you measure? You do know we are not talking about the implement hydraulic pump, but the Hydrostatic drive pump itself. There is usually a special port on the side of the transmission to measure this hi pressure. This is also not to be confused with the charge pump pressure, that is usually a few hundred, Mine is 255 psi. I am assuming you have a workshop manual for this machine. I would not attempt it without it. You say you notice and improvement, but I am a bit confused at the pressures you quoted. I though all hydro trannies operated in this 4000+ area, and the larger they get the higher the pressure. But I could be wrong, I have been before.