Well last year the motor that was in the boat was a running blow up. Head gasket shot and block had micro crack. The risers were too hot to keep my hand on. Fast forward to yesterday put the new(to me) motor in with same exhaust manifolds and risers and let the motor run to about 140, the risers were still too hot to touch. I had water straight piped from hose through bellow port as I took outdrive off to rebuild. So not sure if there is a clog in the system some where or if the risers are just bad or where to begin. The thermostat is new last year btwagree with the comprehensive list scott mentioned, would add increased fuel consumption but may not be easily noticed being its a boat, fuel economy is the last item most boat owners are concerned about.
are you have issues with the cooling system not working properly?
Just ordered a set last night. Also with this I noticed there are 2 different wet joint gaskets one with 2 long openings and 2 pin hole type openings and one with 4 long openings. Is there a difference as far as what they do? I'd assume 1 would allow more water to go through than the other. Is that good thing or bad thing as compared to the one with the restricted flow?Get new manifolds