1975 Johnson 70 Horse Water Pressure Source Needed

[Gordon02]

Guys, I want to add a water pressure gauge to my 1975 Horse Johnson. OMC did not start the "pee-hole" out the right side of the lower cowl until the 1978 models. There was a factory Service Bulletin that was sent to dealerships on how/where to drill and tap the barbed fitting. Thanks in advance!

Gordon

 

[Cat nip]

Either in the side or top of the exhaust cover is where they can be located.

 

[Gordon02]

I was told that there was a factory service bulletin that included a full-sized template that could be taped onto the motor showing exactly where to drill. It included the drill size and tread tap. Grease was added to the flutes of the tap to catch the chips made when cutting the threads. I have been looking for that bulletin for years now. I guess I could always buy an old exhaust cover and make a plan/pattern from it. This will help - gets me looking in the right area. Gordon

 

[Cat nip]

I thought the template came with my water pump kit but i dont see it in there. Here is a picture of where my pressure gauge is hooked up and it is the original location fore the tell tale stream. My tell tale is now located on the top of the exhaust housing on the block itself at 3/4" in from the outside of the plate and 2" forward of the back of the exhaust housing. I cant upload a photo of that for some reason?

 

[Cat nip]

If you look through my profile you might be able to see the 2nd picture i was trying to upload. My idea board seems to be the only place i can upload it to. Hope this helps. Also the template you were referring to was to relocate the tell tale due to air pockets causing overheating. So maybe if you re word your web search you may have better luck finding it?

 

[Gordon02]

Thanks for the input. I went by a friend's shop on Wednesday where he's got several trashed motors and found an exhaust manifold and cylinder head. The flat area just ahead of the thermostat on the top of the cylinder head looks perfect for a 1/4" NPT fitting to be drilled and tapped for a source. I confirmed there is plenty of "meat" for the threads and the source is ahead of the thermostat so pressure is always there. The idea came from my 2 Chrysler outboards that both have plugs specifically for this purpose. I'll be taking photos before/during/after and posting for others. Again, thanks! Gordon

 

[fireman57]

It was service bulletin 1144. I used to have a copy of it but can't locate it right now. Maybe someone else on here has it now that they have the number.
It is located on the top of the head to make sure there are no air pockets. I did it to my engine after it overheated because of it. Worked great and was easy to do. Still looking for it.

 

[fireman57]

Here it is. Hope the link works on here.

http://continuouswave.com/forum/viewtopic.php?t=265

 

[racerone]

That service bulletin is for the newer 56 cubic inch blocks.

 

[fireman57]

Damn. Didn't read it well enough. Thanks for the catch racer

 

[fireman57]

Here it is right here. I put mine on the top of the head. Had no problems after that.

https://forums.iboats.com/forum/eng...aq/228380-johnson-evinrude-adding-a-tell-tale