Tell Tale

[bob1340]

I have a 1971 18 HP 18102S motor I am getting ready for usage. I would like to do a Tell Tale on it. Any suggestions on where to tap into the water jacket? Can I just tap into the thermostat cover and use that?

Thanks, Bob

 

[choppermn27]

Re: Tell Tale

I also want to know this question. Can you tap into the thermostat cover on these? Some Guru has to know the answer.

 

[bob1340]

Re: Tell Tale

I also want to know this question. Can you tap into the thermostat cover on these? Some Guru has to know the answer.

And if we can, what size line?? How would would copper work?

 

[Cofe]

Re: Tell Tale

I would not tap into the thermostat area for a tell tale. A tell tale is only to tell if the water pump is pumping. Putting it in the thermostat would not work until the thermostat opened.

Later year motors have them mounted in the exhaust water cover, at the upper corner. Here is a pic for the location. Hope this helps you out.

 

[bob1340]

Re: Tell Tale

I would not tap into the thermostat area for a tell tale. A tell tale is only to tell if the water pump is pumping. Putting it in the thermostat would not work until the thermostat opened.

Later year motors have them mounted in the exhaust water cover, at the upper corner. Here is a pic for the location. Hope this helps you out.

Thanks for the info. Actually there is pump pressure at the thermostat cover all the time. The thermostat should allow a certain amount of bypass before it opens fully. I'm thinking about drilling and tapping into the cover and seeing what's happening with that. Worse case senario is I either put a plug in the hole or replace the cover. . I will also see if I can determine if there is a better spot on the Cover you show.

How small of a tube can I use?

 

[choppermn27]

Re: Tell Tale

My OMC mechanic removes the thermostat from all 18-25HP OMC motors of the 50s-70s era, he said one less thing to break.
So i'm going to run this by him, and see if he thinks this is a good/bad plan. I'm going to get the spare cover, add the elbow per the forum guru, add another to the left side of the housing and connect them with a hose.
I'll post pictures if this works out.
Here's the size recommended by the guru in another forum:
You just need two parts. A 1/8 brass pipe threaded nipple to fit a small hose, and a couple feet of speedometer hose. There should be a 1/8 pipe plug on top of the block near the thermostat or on the water jacket cover on the head. Barring that, you can make your own hole on top of the block on the flat area near the thermostat on the top of the head.