EGT sensor install Stock Merc Manifold
 

Where is the best place to install the EGT sensor on a merc manifold. I know that it should read of the 6 cylinder. But how do you go threw the water jacket. Is their a way of sealing the double wall. :confused:


Thanks

BigJake

In my old boat I had it in #7 port on the bottom about 3/8'' from the head. The bottom of the manifold has an area of about 1+" or so of no water jacket. you'll see what I mean when you look down under the manifold and see the paint burnt off, and rusty.
There all like that but I chose #7 because it's the only cylinder that has #5 fire just before that one(1-8-4-3-6- 5-7 -2), So it usually is the hotter one.

I have always been told that #6 is the hottest. I drilled mine into the top of the port in the head. About 3/16 th from the header flange. I drilled the hole to fit just the bare thermocouple not the threaded adapter. I drilled the hole about .002 bigger than the thermocouple and pressed it in.