Im preping my hydro to run, its an OMC 25 with a Yamato 102 foot adapted below the waterpump. It has above the waterline exhaust and has been run alot before this happened.. I was unscrewing the foot drain plug and it was under pressure, maybe 20 or more psi. It had some sign of a little bit of water but ran good last time out and wasnt leaking at all, not a drop. Im thinking the waterpump would not hold such pressure stopped but could it have pushed water into the foot to be trapped behind the seal? Have any of you who race Yamatos ever seen a foot pressurize for any reason? I suspect the pump but wonder too if the gasket could let water in that might be trapped.