Water Pressure Question

[wannagofishin]

Engine: 1986 Merc 75 4 cylinder 2 stroke SN:0A967552<br /><br />Questions:<br />What is the water pressure for this engine? I've been told 15 and 30psi - one's gotta be wrong.<br /><br />I bought an old but new in box Kiekhaefer (made by Stewart Warner) water pressure gauge that goes to 15psi - part #: 91-33371A1. It came with an elbow fitting with threads on one side, nipple on the other. The only place I can see to connect the hose is the outlet hose on the engine using a "tee." There is a difference in the diameter of the hoses though. The hose to the gauge is 3/16" and the other is larger but don't know exact size. <br /><br />Does anyone know where I should connect if above is not correct? Does anyone know where I can find the correct fitting?<br /><br />Thanks,<br /><br />Dan

 

[ricksrster]

Re: Water Pressure Question

They can connect on the block where the tell tals tube connects. Use the proper size tee.

 

[wannagofishin]

Re: Water Pressure Question

I called the local guy and he told me it goes in the head. I found the brass plug between the 2nd and 3rd spark plug. <br /><br />Thanks,<br /><br />Dan

 

[dajohnson53]

Re: Water Pressure Question

go to the teleflex marine website. If you tunnel through the technical assistance and/or installation pages, you'll find installation guides for various engines and also a chart of pressure ranges. It's a little challanging to find, but there's a lot of good info there - stuff you can use even if you don't happen to have a teleflex pressure gauge.

 

[emckelvy]

Re: Water Pressure Question

That's an Old-School Inline-6 Derivative which is more likely to pump around 10-13 psi during normal operation. <br /><br />I'm thinkin' your 0-15 psi gage will work just fine. <br /><br />Wherever you tap into, it has to see full water pressure from the inner water passages of the block. You won't get an accurate pressure reading by tieing-into the telltale discharge. <br /><br />You may also find a hole at the top-rear area of the block, tapped for 1/8" N.P.T. fitting, with a plug in it. This would be another place to tie the gage into, with a 90 deg fitting for clearance under the cowling-mount covers. <br /><br />The brass plug you found at the back of the engine should work, as long as it opens up into the water passages.<br /><br />HTH...........ed