Temp Gauge

[mrelmo]

So I have a 1995 70HP with the fast start feature, it has 2 wires coming off the motor I would like to know how to hook up a temperature gauge. And what is the proper running temp.

[boats.net]

When you buy a temp gauge then also buy the temp sender to match gauge and bolt sender to engine block then it will read properly.

[mrelmo]

where does the sender bolt on and what should the temp be

[boats.net]

Most of them bolt under a head bolt or a water jacket cover bolt.

[Joe Reeves]

This is the standard "L" bracket that the bra$$ sensor screws into. The other end of the "L" bracket is normally attached to the head with one of the water jacket bolts. NOTE: Leave a .010 gap between the sensor and the head surface to avoid a false reading.

[mrelmo]

OK so the sensor does not need to make contact with the water that is flowing through water jacket right, originally I thought that the water needed to flow over the sensor. So it looks like the sensor is picking the temp of the engine block or head not the actual water temp. I really do not want to remove a head bolt and I have seen a "blind threaded hole" near a head bolt, but as you said I would need to make sure the sensor does not bottom out and make contact with the metal casting, also what is the temp that the motor should be running at

[Joe Reeves]

Originally posted by mrelmo View Post

what is the temp that the motor should be running at

No idea, however the thermostat opens at about 143 degrees so it would be slightly higher than that... about 150 or so.

And yes, the heat sensors are very touchy, registering actual air heat. Some engines have a actual screw in cavity on the head for the sensor, however I retired in 1991 and you'll need to get advice on that area from someone else. Try the fellow friends on the forum at MarineEngine.com .

[jetblue319]

hi , enclosed is a photo of a 97 225 evinrude thermostat cover. to the left of the 7:00 o'clock thermostat cover bolt, is a threaded slot, i was told you screw a sensor for the temp gage. as for the wiring sorry i dont have that yet,
jet

[mrelmo]

Thanks for the photo any idea what the thread is because the sensors that I have seen have been 10mm. I would be surprised that it would be a metric thread

[jetblue319]

i would think the thread size are the same for the 97 evinrude 225 the threads are 1/4-18. i attached a photo of the sender used on a sierra lido temp gage.

[mrelmo]

OK so I ordered a cylinder head temp gauge (faria) that comes with a sender. The thinking is that the actual water temp in the water jackets or the cylinder head temp can be monitored as they more than likely will not be the same temp, upon initial start up,a base line reading will be made during normal operation (regardless of the numbers), any movement after establishing a normal reading will be easily monitored. I don't have any temp issues now I just want to be able to keep an eye on it rather than a horn activated by the thermostat. Thanks for all the replies, I will be using the threaded hole in the photo that jetblue 319 provided

[jetblue319]

i also notice a thread access on top of each cylinder bank but that's on the 225. if you want to monitor engine cooling i would suggest a water pressure gage also to make sure the water pump is working also, good luck
btw i dont see your size engine in the seloc manual you wrote 1995 70

[mrelmo]

Hmmmmm model is E70TLEOR

[mrelmo]

OK Jetblue my 70hp is different than your 225 motor I don't have that threaded hole and I really do not want to remove a head bolt at this point I am thinking of using a bolt from the thermostat housing it won't give me a true temp for the cylinder head but maybe a reference point to watch, any thoughts from anyone?

[jetblue319]

i see you have a 3 cylinder engine , my book is for V engines,sorry. have you check on top of the cylinder? i also have a thread holes on each cylinder bank on top and near thermostat.