Hello everyone I am new to the forum. I found this during a search to my problems. I do alot of my own mechanic work and have owned a few different Johnson and Evinrude engines. I have a 1993 Evinrude 88 SPL that is overheating. I can put my boat in the water, idle out away from the marina and run at WOT (5000 rpm) for about 3 minutes and my horn goes off. The starboard head is running at 160 degrees and the port head is 200 degrees. (I have tela-temp`s installed on each head) I have installed a new water pump, cup and plate assembly, exhaust cover gaskets,thermostats, relief valves and springs, head gaskets(twice), 4 water restricters, head cover gaskets, powerhead to exhaust adapter gasket, and water passage cover gasket. I found sand in the head covers and in the small passages in the exhaust manifold and cleaned everything. I did notice when I had the powerhead off that there was carbon deposits in the port side exhaust passages that were not in the starboard side. I feel something is wrong on the port side but what could it be??????????? Can anyone help?