I have a 1989 Larson, 3.0 four banger, SE106 outdrive, which I'm sure is a re-manned Mecruiser. Anyway, I drained the water from the block and manifold the other day....was rare for here, but supposed to be 26 degrees, East Tn. So, today I take it out....78 degrees. Runs like a champ, but when...