Posted by Bruce, CC 27 MKIII (188.8.131.52) on May 24, 2004 at 15:13:49:
In Reply to: engine temp posted by Dennis Lancaster on 15:05:04 05/17/04:
I have a raw-water cooled A-4 and have had similar "problems". While not directly the same issue, it too happened to me when the boat was heeled in such a way as to have the intake on the deep side of the boat. For a raw-water solution, I flushed out the block & such, and this helped quite a bit, but didn't stop the problem. I would doubt this would help with you.
That being said, however, I believe the issue results from the reduced flow that probably occurs because the pump has to draw the water from a deeper depth. Also given what little I know about physics, the greater "suction" caused by the increased flow across the intake due to hull form and being on that particular tack.
In the end, I kept my eyes on the temp. gauge and throttled back a little bit if the heat started creeping up. That and easing up the sails a little to reduce the amount of heel has kept it in line.
If you haven't replaced your impeller for a while, I'd do that too.
Hope this (limited) information helps.