1983 merc 70 hp temp guage??

[tlwilk]

Would it be possible/useful to install a water temp guage on a 3 cyl merc 70. Need to know if I will be using the guage before I layout the dash. Also does this motor need to have the cooling system modified similiar to what I have read about some of the other 3 cyls to prvent overheating the top cylinder? Thanks, Tom

 

[rickdb1boat]

Re: 1983 merc 70 hp temp guage??

Tom,<br /><br />It would be very beneficial to have a temp gauge on you boat. That way you can moniter not only the water temp, but the condition of the water pump as well. If your temp starts rising gradually, it's time to look into the pump. It can also tell you if you have a restriction in the cooling intakes(Like picking up trash on the water and blocking the water pick-ups). Wouldn't be without one myself. It's well worth the piece of mind! Because the only other thing you are depending on is the overheat warning horn and that may be too late! I believe the 3 cylinder problem you are referring to had to do with OMC products. Maybe others will know if 3 Cyl. Mercs had a problem, but I have not heard of it.

 

[tlwilk]

Re: 1983 merc 70 hp temp guage??

Is this motor equipped with a port for a sender or will I need to modify it to receive the sender?

 

[rickdb1boat]

Re: 1983 merc 70 hp temp guage??

Honestly, I don't know if it has the blind hole in the head or not. If not, there are mounts that hold the sensor against the head to sense the temp. Others will know on you Merc. Meanwhile, here's some reading:<br /><br /> web page PDF file

 

[agrazela]

Re: 1983 merc 70 hp temp guage??

I have a 1978 Mercury 70hp ("Thunderbolt 700" model). On mine, there is a small threaded plug just below and to the left of the top cylinder on the rear of the head. This is 1/4" NPT, and this is where the water temp sender screws in.

 

[tlwilk]

Re: 1983 merc 70 hp temp guage??

Thanks, I have that port on mine. Now if I can just figure out how to mount a tilt/trim sender I'll be all set.