1973 SRV 190 Overheating

[DavidBaustert]

Hi all. Just picked up a 1973 Avacado Green Sea Ray SRV190 complete with a Ford 188 and 888 outdrive. Just replaced the raw water pump and the boat is still overheating. Pulled the thermostat housing and there is none. I plan on picking one up in the next few days. I've been looking through the Mercruiser service manual at the cooling system diagram, and I'm a bit stumped as to what could be causing the motor to overhead. If I pull the hoses coming from the front of the log manifolds, the boat does not overheat. The manifolds are warm to the touch, and the elbows are cold to the touch. Does this sounds like clogged manifolds? Anything else I should look at? Thanks.

 

[bigcrunch]

Oil look normal? have you done a compression and leak down test on cylinders? vacuum check? sparks all look the same? when you do run it and it warms up pull off the valve cover breather smoke coming out? Just some preliminary items to check for general health of the engine...