Hello, I have just acquired a real nice 445 from my uncles estate. We don't know a whole lot about how deep the restoration on the tractor went. I believe it was only a cosmetic restoration and nothing mechanical was done. It's been sitting for about 5 yrs due to his health at the time and I'm just starting to get it ready to use again. I filled it with propane and it starts and runs great. 3pt works and the ampli torc works. The problem I'm having is the oil pressure acts funny on it. Upon start up it builds 35lbs of pressure and will slightly raise with rpm increase but at about 1/4 throttle it starts to lose oil pressure. It never drops below 20psi but this seems opposite of what it should do. I attempted to adjust the external regulator on it and it seems to be working. I got an increase in pressure at idle but the pressure still falls with rpm increase. Just wondering if anyone has suggestions on what to look at next.