Wet exhaust hose temperature 454

[northern]

Last fall I took off the manifold risers had them sand blasted and cleaned. They were fine with no sign of pitting corrosion. I replaced the raw water pump on the starboard side as the shaft seal leaked and I replaced the impeller in the port raw water pump.
Port engine temp are as follows;Cast iron risers 55F, Thermosate housing is 148, Wet exhaust hoses are 158 on port side of engine and 165 on starboard side of engine.
Starboard engine temps are as follows: Cast iron risers 63F, Thermosate housing is 151, Wet exhaust hoses are 158 on port side of engine and 180 on starboard side of engine.
I also had the heat exchangers cleaned and tested. Temperature on them are Port 180F Starboard 176F
The wet exhaust hose temperatures are about a foot past the elbow on the top of the riser. The bottoms are warm. Six inches past the hot spot the hoses are warm as on the bottom. Did not take temperature but are like bath water temperature.
Does any one know if theses temperatures normal. If not is there a fix. Raw water flow seems to be the same in both engines.

 

[Fun Times]

My first thoughts when seeing them temps on the exhaust risers are either you could have two different style gaskets between the exhaust risers and manifolds, Or you have one set of gaskets on backwards, Or you also might not be getting the right amount of water flow coming out of the thermostat housing check balls if your system has them.

(1) Did you use OEM Mercruiser Gaskets using your engine serial number?

(2) Did the gaskets come with detailed instructions on what way to install them?

(3) If your not sure, What is your engine serial number?

(4) What Part number did you get for the gaskets?

(5) Is your exhaust riser standard size or do you have a 3 inch or 6 inch spacer between the manifold and riser?

If you would like I will try to double check for you.:smt024

 

[northern]

Boat Tech thanks for the responce. The following is some additional information.

The gaskets I got form a Mercuiser dealer and were exactly the same as the ones taken out and I put them back in the same way. The gaskets are solid and stop the flow of anti freeze from mixing with the raw sea water.
The risers are 6" tall with no spacer and are all cool. It is the top of the hoes a foot down from them that are warm.
I have a jet boat with a GM 350 and the hose is cool for the entire length but it is only 2 feet long.
I do not have the serial Number of the motor as it was according to the dealer on a paper tag on top of the carberator plastic cover and has worn off.