I have a Merc 228 84 model that is overheating at idle but runs great the rest of the time. It is currently in the water so I pulled the water inlet hose off just above the water pump and started the boat, there is enough pressure that I can't hold my hand over the end, so am I safe to assume (I know bad word) that the pump is still good, and where else would be a good place to start. Thanks Rick
