Engine Cooling Fluid Change
Boat motors are not equipped with radiators like automobiles are. Nonetheless the same heat dissipation function must be accomplished by either of two principal methods: 1) raw water system in which raw sea water is circulated through the engine and then returned to the sea through the exhaust. 2)fresh water system in which raw water is circulated over a heat exchanger , [then evacuated via the exhaust] in which fresh water (anti freeze) circulates through the engine. Here in the San Fransisco Bay and up into the Delta, freezing is generally not a problem we need to be concerned about. However, just like the other engine fluid systems anti-freeze changes over time, becomes dilute from topping off, becomes contaminated by foreign materials like rust, dirt etc. Most manufacturers recommend changing anti-freeze at least every two years. We say do it every year primarily because of the important ant rusting/scaling properties of the anti-freeze can become compromised in only one year of use. Best to change the anti-freeze and filters out at the end of the season, thereby providing maximum engine cooling system protection all winter long and also getting the added benefit of being ready for next season early.