I have a recurring problem in my 15hp kicker that I use as an aux
engine. I operate in salt water and corrosion in the aluminum block
builds up to the point that it causes blockage in the cooling system.
I can clean it and flush it out with vinegar and the problem is solved
temporarily, but a month or so later, the problem is back. I don't
have easy access to fresh water to flush the engine after each use and
the zink appears to be in good shape.

I've been tempted to strip down the engine and coat the cooling
channels with zink chromate paint, but am not sure that I can get a
good enough bond to the aluminum to prevent peeling and an even worse
problem.

Has anyone found a solution to this?