where to add water pressure hose for gauge on 90hp elpto

[wn6ngp]

'00 Mercury 90hp ELPT 2 stroke. s/n ot087666 built in '99

Please see attached pix. I added a line to measure water pressure. It seems to work, but I have a couple of questions.

Is this the right place to add that hose barb?

I notice some green corrosion on it, is that going to be problem? I think its
just a copper barb. The tell-tail has a right angle nylon/plastic tap.

 

[wn6ngp]

Anyone out there added water pressure gague to these old school ELPTO 2Str? the shop manual doesn't show much, only the connection for the tell tail that's on the port side of the motor.

 

[Vernon351]

I'm no expert on outboards by any means, but I'm pretty sure that plug in the picture is for water temperature, not water pressure.

 

[Johnson110]

I did one on my 115 mercury it had a plug in the head that I took out and installed the the water pressure gauge into the head, I believe it screwed into head. Can you unscrew that blue hose out if so that is where you can screw the fitting in for the water pressure hose.

 

[wn6ngp]

I think I have done what you have suggested. See the photo where the red arrow points? I have threaded that plumbing fixture into there and it seems to read the pressure as expected. The pressure indicates that pop-it valve operating like you expect.

I was just wanting to find out the official place to connect. Is that what you are referring to as blue? Actually its kinda blue/green due to brass corrosion that is taking place on that fitting. The photo does make it look blue.

 

[Johnson110]

Yes ( referring as blue) that is how I hooked my water pressure gauge which to me is better than a water temp gauge, you can see by the pressure of the gauge how the water pump is doing. I took a noted reference of what the pressure is after installing a new water pump so I can tell how good it is cooling.

 

[wn6ngp]

Actually, I was also trying to figure out a way to measure the water temperature too. Note that "stuff"with the red connector poked into that cavity on the head. What I have done is shoved a temp transuducer in that hole along with thermal grease, Not sure how good of a measurement that is but it does show temp rising.