Merc sportjet thermostat issues

vprgtsr001

Cadet
Joined
Jul 11, 2004
Messages
24
'97 Merc sportjet 175hp v6 in a regal rush.

Because the boats so old i cant find replacement parts from regal and i dont know if thermo is stock for merc or some kinda manufacturers option.
The gauge on the dash goes from 60-220. When key's on to ignition the needle flickers but after running the motor and being out on the water the needle doesnt move above where it rests. I'm afraid the gauge or sender might be bad so i traced the line to the engine and found it going to a silver nub, when i grabbed the wire to wiggle it to check for corrosion the whole nub popped off.

http://img687.imageshack.us/img687/9518/img00231f.jpg

Is a picture of me holding it. I would assume this is the sender? It wasnt screwed into the block, only part of a metal plate attached to the side of cylinder wall near the head. I guess it was press fitted at one time and broke free

http://img651.imageshack.us/img651/2626/img00233.jpg

is a picture of the plate that the (sender?) was attached to. When i wiggle the wire on the top it makes the needle move. Has anyone seen a sender just touching the powerhead like this and not screwed in? And where would i go about finding a replacement. All the ones from iboat look like they screw into powerhead. Any help would be appreciated.
 

vprgtsr001

Cadet
Joined
Jul 11, 2004
Messages
24
Re: Merc sportjet thermostat issues

Ok, update: well i found out along with the aftermarket thermostat the motor is equipt with an in block sensor at the same location. 4 wires running out of it. 2 beige/black 1 black (grounded) and a beige/blue. They're all running to the engine somewhere. The gentleman at my local parts dealer said that these sensors (4 wire sensors) can be hooked up to a temp gauge but he doesn't know how. Does anyone know how or can supply me with a wiring diagram for a 97' merc sport jet 175xr2?
 

column

Recruit
Joined
Jul 11, 2010
Messages
5
Re: Merc sportjet thermostat issues

Try posting in the pwc repair section. That is where most of the sport jet issues are taken care of.
 
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