I am new to forums in general so I hope this is the right way to go about this. I also need to apologize for this being a long post. I have a 1988 mercury 50 hp 3cyl 2 stroke outboard that I believe to be over heating. Here's what I've done so far= new water pump and housing, removed cleaned and replaced gaskets on both of the side covers,same with the "head"cover. I've removed both carbs and cleaned them twice, flushed power head with covers off. I used a temperature controlled soldering iron,ir thermometer and dvm to check the temp switch. The switch closed around 250 deg and was repeatable. I'm sure that I left something out but, that's all I can think of right now. The motor is on a 18 foot lowe pontoon (since new)and over heats at 3/4 throttle. I don't know what the rpm is but I hope to have a tachometer soon.
