Normal operating temp. for 200 Merc. Optimax?

Lizzy K II · #1 (**permalink**) 03-08-2010, 05:47 PM

What is the normal running water temp range for a 200 hp. Optimax?

boats.net · #2 (**permalink**) 03-09-2010, 08:56 AM

The thermostats open at about 118 degrees and overheat alarm activates at about 180 degrees.

Lizzy K II · #3 (**permalink**) 03-09-2010, 10:01 AM

So when I look at a water temp gauge. I should see the temp. get up to about 120 and then drop off some?

boats.net · #4 (**permalink**) 03-10-2010, 10:37 AM

Normal range would be 120-180 degrees.

Lizzy K II · #5 (**permalink**) 04-12-2010, 04:55 PM

Bought a DDT scanner last week and hooked it up and watched the water temp on each head while it ran at an idle. Starboard head was always about 30-40 degrees hotter than the port head. Is this normal? I just installed the new 130* thermostats and covers. The other motor that I haven't installed the thermostats on also has this issue. The overall temp did not get as high on this motor, but the starboard head was still about 30* hotter than the port head.

The motor with the new thermostats ran with the starboard head at 150* and the port head about 110*. This does not seem right to me.

Also, what does the dash mounted temp. gauge get its reading from? The port or starboard head?

Lizzy K II · #6 (**permalink**) 04-13-2010, 06:19 PM

Woud a representative from boats.net be able to answer my questions?