On a I6 '77 1150, best spot for temp probe?

[kungpaoshizi]

Going to be replacing the wiring harnesses here soon, there's 1 extra wire and I'm thinking I'll turn it into a temp gauge wire.
The only question would be, where would be the best place to stick the temp probe?

Thanks very much!

 

[Faztbullet]

Re: On a I6 '77 1150, best spot for temp probe?

You dont need one as they run so cool a gauge will hardly read, better to spend your money on a water pressure gauge..

 

[kungpaoshizi]

Re: On a I6 '77 1150, best spot for temp probe?

Ahh good idea Faztbullet! Though, where would I put that? I'm assuming I would have to drill something... unless I attach it to the pee hole, though that isn't the same pressure as the water is internally... hmm

That would matter more than temp in the event something starts to break...

Anyone else have any suggestions for the single wire?

 

[ajgraz]

Re: On a I6 '77 1150, best spot for temp probe?

I went temp sensor instead of pressure. The old Merc's have high-volume (not high-pressure) water pumps, they don't exert much of a pressure reading and will fluctuate wildly, it would drive you nuts.

It is true that with these old non t-stat Mercs the temp gauge will sit pegged to the left because they run so cool...basically, that means ANY movement of the gage means there's a problem, stop the boat and check it out. Perhaps call it an "indicator" more than a "gauge." Saved me many times when kelp got stuck over the water inlets in the leg.

You should have a 1/8" NPT (IIRC) pipe plug in the rear water jacket, about 1/2 to 2/3 up from the bottom. That's the spot to put the temp sender. If water flow gets obstructed or stops, the water jackets drain below that level and the temp sender/gauge will respond VERY quickly.

 

[Chris1956]

Re: On a I6 '77 1150, best spot for temp probe?

Kung, Remove the black plastic elbow that supplies the tell tale. Insert a brass tee (female,female,male) into the water jacket cover. Now screw the elbow back in, and on the other port add the brass hose barb for the water pressure gauge. The temp gauge is useless as Fazt says. Try to get a 0-15PSI gauge as it will read about 1/2 at crusing speed.