Re: Cooling Water Flow in Outboard ***
Cooling systems are going to be different for make and size/configuration.There is multiple cooling paths in your V-6's.My Mercs have a pressure relief valve thatopens & allows water to the center of block and exhaust plate,the heads each have a thermo that opens on temp. (143)I am breaking in a V-6 that had a stuck closed relief poppet valve,eliminating half of water circuit.I pulled the thermos's for full flow and test,not a good idea.You can't always trust the telltale,it can get flow while thermos are closed,poppets stuck,etc.Just tells you the impeller is providing water.I removed the poppet valve and put thermos back in,motor runs near normal temp.I came here to post a question if this will create any hot/colds/warping/backpressure concerns.Thermos are flowing,heads are cooler than block. There is more to know,basically find where the problem is and correct it,don't run too hot or too cold.The speed of the pump impeller and engine load have an effect also with volume of water provided,you can actually run cooler at higher speeds.
