OMC Tech-Temp sending unit on a 1985 Evinrude 140 looper

[powrguy]

I am putting a 140HP Evinrude on my boat, and I want a temperature gauge and not just warning buzzers. There are threaded bosses next to each cylinder head's thermostat housing.

These look to be 3/8" holes, fine-threaded, and I need a sending unit for them. I assume that's what these bosses and wells are for, but don't know the thread size or what manufacturer has the senders (my gauge is a Teleflex, but the 3/8 NPT threads are too coarse, from the looks of them)

Any ideas here?


thanks
271344

[racer]

Brp #174675

[powrguy]

Brp #174675

Okay; got it. I did some more checking and it APPEARS to be 1/8" NPT, with a depth total of about 1". I assume this is for the sending unit location on each head?

thanks

[flabum1017]

Most people do the higher head.... some use two temp gauges , one for each head or you can do one gauge, two senders with a switch to select which head you want to monitor