View Full Version : 97 ProStar 190 with LT1

06-01-2006, 09:42 PM
What water temperature does the LT1 typically run at? Mine appears to be about 140 degrees, which registers very low on the guage. Everything seems to run just fine, but this appears to be quite a "cold" temp to me.


06-01-2006, 10:13 PM
I regularly drive my ski partners '97 205 with the LT1 and it always runs at about 140 which is pretty low on the gauge. Sounds like all is normal.

I think the temp gauge on that era MC is pretty stupid. It ranges from 120 to 240 degrees with 180 being right in the middle. Normal operating temp on these boats is in the 140 to 170 range. If the guage pegs you are toast. The gauge in my '88 ranged from 100 to 220 with 160 being straight up and in the middle. A little better design.IMHO

Also remember that these gauges are not all that accurate. According to the Teleflex site the accuracy is + or - 15 degrees. Bottom line is make a note of where your boat is running on the gauge normally and any reading substantially more or less is cause for concern.

06-02-2006, 12:21 AM
My '97 w/LT1 runs about 160

06-02-2006, 07:24 AM
in the 140-150 range is normal for mine

06-02-2006, 09:06 AM
Should be between the temp range for the two thermostats...the lower one is 140, and the upper one is 160 degrees.

It should be at 160 once warmed up. If you are running "cold", you will use more fuel than necessary. Check to see that one of your thermostats (likely the upper one given your current temp) isn't stuck open.

When I got my LT-1, the previous owner had "solved" a bad temp sensor problem, by removing the 160 degree t-stat altogether...my boat ran around your temperature when there was no upper t-stat at all. That is why I suspect that your upper t-stat is stuck open.

Good luck.

06-02-2006, 09:33 AM
Mine runs at 160 consistently regardless of watertemp, unless the water is real warm, like in AZ summertime, then maybe up to 170 if I'm gettin' on it hard.
Your guage s/b reading engine water coming thru the top t stat (160 deg). The bottom tstat that runs to the exh manifolds s/b a 143 deg tstat.
Sounds like you're running a 140/143 in the upper tstat hole.
If you haven't replaced the tstats in a while, it's good insurance anyway. Remember the top, 160, needs to be proper w/ holes drilled in it. I bought an automotive tstat and just matched the holes in the old one.

06-10-2006, 11:22 PM
Thanks guys. I took my top thermostat out today (the 160) to replace it, and found that it had a small piece of rubber stuck in it that was keeping it open. Unfortunately, I had been supplied the wrong gasket from SKIDIM, so I pulled the rubber bit out and reinstalled the original 160.

Temp now holds consistant at 160 instead of the 120-140 that it had been running prior.

I appreciate the help and confirmation.