I have a 2004 155 with a 4 tek engine. It has closed cooling and is not supercharged. My question is, is it necessary to pump antifreeze into the exhaust manifolds etc .in the raw water section or not. From what I have read it is not necessary as long as you run the engine enough to dispell any water in the system after taking it out of the water and flushing. The manual only addresses the closed system and the need to check the coolant and replace if necessary.