140 thermostat?

Happy Dayz

Happy Dayz

Active Member
Jun 26, 2017
543
Sarasota, FL
Boat Info
'06 260 Sundancer, 6.2, BIII, Kohler 5kw
79' classic Kona Family Cruiser jet boat..
Engines
6.2 w/ BIII, 502 w/ Berkekley
So on another forum I was told for raw water cooling I should be running a 140 thermostat not the 160 that is in it and on the parts list..

6.2L Bravo III

What does CSR say?... Thanks in advance
 
All of my boats have been rawater cooled in freshwater, all have had the 160* thermostat - that translates to a running temp of 170-175*. I think 160* thermostat is pretty much the standard for marine engines these days, but there are some camps that say in salt water you should run the cooler 140* thermostat - something about saltwater and salt deposits at the higher temperatures.
 
I also like the 140s.... It runs around 150 to 155 when warm and its a nice temp...
 
Siboatguy said:
I also like the 140s.... It runs around 150 to 155 when warm and its a nice temp...
Click to expand...

giving her a run today so will see... stoked to get on the water!
 
We have fresh water cooling (anti freeze) and 140 thermostats I was told they were used to help stop salt deposit. Engines run 160 F measured with heat gun at the thermostats.
 
I’m pretty sure thenrawmwater T stats are supposed to be 140 and the fresh water 160.
My old 300 was raw water cooled and I used 140’s.
When I repowered I installed FWC on the new motors and used 160’s.
 
update:

140 thermo... not long pulling out temp up to 150's, up on plane, holding 158, then started to tick up.. 171... on another run back in about 30 min in was up to 176.... spikes to 180s coming off plane.. cools back down to 165...

seems just doesnt get enough water... UUUGGGGGG

when back flushing from raw pump out through outdrive water flows freely..

going to do barnacle buster...
 
you could just run the engine without a t'stat temporarily.....if it still runs hot then the problem is definitely not anything to do with a t'stat.....but I think you have already proven that....

cliff
 
I think it was in one of your other threads about this, but we talked about the 140* t-stat as being a "band-aid", not a solution? Lowering the t-stat is not a solution to an overheating engine. When you say "water flows freely", that doesn't tell/show how MUCH water. I think we discussed this, as well... doing the water pump test. Have you done that, yet? I don't recall if you had checked the manifolds and risers, as well?

Your other post was the one with the scored impeller housing, right?
 
Lazy Daze said:
I think it was in one of your other threads about this, but we talked about the 140* t-stat as being a "band-aid", not a solution? Lowering the t-stat is not a solution to an overheating engine. When you say "water flows freely", that doesn't tell/show how MUCH water. I think we discussed this, as well... doing the water pump test. Have you done that, yet? I don't recall if you had checked the manifolds and risers, as well?

Your other post was the one with the scored impeller housing, right?
Click to expand...

manifolds, risers and elbows newer and cleaned out..

the scoring on the pump is nominal relative to the challenge, imho

the 140 was another test and specific question but relative to the overheating...

4k rpm...5.6 psi

also going to do the pump test...
 
Happy, I got your PM. In response to your question about the intake hose... Actually since you likely have the 3-point drain system, you can either grab the hose from the input side of the water distribution housing or the power steering cooler.
 
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