I have a 96 225 EFI that is overheating. Some back ground info. I have a new lower unit standard ( after market. New thermostat, stratos, sparkplug, tune- up. It just gott out of the shop. Today was the first day of running it. After 5 min the engine started to overheat and the alarm went off. Water pressure is 15 - 20 and the engine was pissing. PLEASE HELP.