Overheating 6.5k kohler Gen resolved
- Wkuhilltopperfan
- Deck Hand

- Posts: 65
- Joined: January 10th, 2016, 2:47 pm
- Vessel Info: 1998. Mariner 350 . Twin 7.4 engines / kholer 6.5 gas Genset
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Overheating 6.5k kohler Gen resolved
Hey guys and gals! I live in a area where the waters can get up in the 90’s and it’s caused Generator overheating shutting down year after year for me in my 350 Mariner. I’ve been told that the factory heat exchanger was just not big enough for water this warm. I purchased a secondary water to water heat exchanger which I located outside of the generator housing, this not only allowed for a better cooling it also added almost another 1/2 gallon of antifreeze to the closed loop system. I’ll attach a few photos and the results I got .... I was very excited with a 70 deg reduction in heat and that was before the water hit the factory heat exchanger.





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1998 350 Mariner
- Midnightsun
- CYO Supporter

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2007 41CMY
Volvo D6-370's - Location: Montreal, Canada
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Re: Overheating 6.5k kohler Gen resolved
Thanks for the thorough write up. It's posts like this that make our forum so valuable to all. 

- Wkuhilltopperfan
- Deck Hand

- Posts: 65
- Joined: January 10th, 2016, 2:47 pm
- Vessel Info: 1998. Mariner 350 . Twin 7.4 engines / kholer 6.5 gas Genset
- Location: Nashville, TN
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Re: Overheating 6.5k kohler Gen resolved
Midnightsun wrote:Qr Bbpost Thanks for the thorough write up. It's posts like this that make our forum so valuable to all.
I know I have alway appreciated others making post like this, us do it yourselfers need this stuff lol . Thanks for the kind words
1998 350 Mariner
- km1125
- Admiral

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Re: Overheating 6.5k kohler Gen resolved
Is that the actual sea water temperature you're measuring and it dropped from 167F to 96F??
- Wkuhilltopperfan
- Deck Hand

- Posts: 65
- Joined: January 10th, 2016, 2:47 pm
- Vessel Info: 1998. Mariner 350 . Twin 7.4 engines / kholer 6.5 gas Genset
- Location: Nashville, TN
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Re: Overheating 6.5k kohler Gen resolved
The water temp coming out of the generator was 167 and after it came out of the new heat exchanger I installed it had cooled back down to 97 before it went back into the generator. I took the water temp this morning and it was 88 degrees after all the rain we have had. So it’s pulling the water temperature down to within 10 degrees of the lake water. Just remember this is a closed loop system that uses antifreeze and only uses the lake or sea water to pull the heat away from the generator. Some generator setups only use lake or sea water for all cooling
1998 350 Mariner
- cordesjoanne
- Scurvy Dog

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Re: Overheating 6.5k kohler Gen resolved
You can get the best advice from the generator and engine study expert from CSDG - http://csdieselgenerators.com/contact-us/
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Viper
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