Fresh or Raw Water Cooling

[Ori Shalom]

hi all,

i'm also trying to figure out what kind of cooling system i have on my 6.2 mpi.
i'm attaching a picture. hope someone can help point some stuff on it.

thanks.

[mmwjr]

Hi Ori, I would recommend that you have started a new thread as this one is several years old and some of these folks are no longer with us.

To answer your question the engineis raw water cooled as I see no heat exchanger. The exhaust is mercs dry joint system.

[shrew]

Agreed, I moved to a new Thread.

The picture doesn't include a heat exchanger. There are Raw Water (Open) and Fresh Water (Closed Cooling) systems. The latter requires a heat exchanger. For Closed Cooling, they come in 1/2 systems which cool the engine only, or Full System which does the Engine and the manifolds and risers. Do you have a heat exchanger somewhere? It will be a long black metal cylinder with hoses connected to it.

[Ori Shalom]

thanks for the fast replay guys...
I don't have a heat exchanger... so i understand i have a Raw water cooling system.

i read that i't important to wash the engine raw water cooling system with fresh water after every run,
how is that possible if i have an inboard motor?
is there something i need to do after every run to make sure the cooling system remains ok?

thanks,
Ori

[mmwjr]

Most people don't flush their raw water cooled engine as an FYI.

Do you keep the boat in the water, trailer, hi-dry? If not stored in the water you can flush with a hose using ear muffs on the outdrive assuming the boat is an I/O. If kept in the water a flushing kist can be added that installs in the raw water inlet hose before the t-stat housing.

[Capt Al]

If you have an I/O set up and your boat stays in the water you aren't going to flush the engine because the water intake will remain in water. If you have an outboard engine that lifts out of the water or you put it on a trailer after boating then you can use earmuffs for a fresh water flush...

[Ori Shalom]

my boat is in the water,
so it's possible to connect somehow a hose with fresh water to the water intake and run the engine with that fo a few minutes?
i guess i need to find the inlet hose and somehow bypass the raw water with fresh water, where can i find the flushing kit that you meantioned?

is it even important to do that? or to do it once a year when i take the boat out for handling anyway is enough?

sorry for all the newby questions... i'm still learning
thanks a lot,
ori

[mmwjr]

Never be sorry about wanting to learn.

I know folks who flush all the time and others who only do it when they winterize. As far as I can tell neither type of folks have more or less issues with the engine.

Here is a link to one such flushing kit:

http://www.go2marine.com/product/930...valve-kit.html

[Capt Al]

You can buy a flush kit but the problem is that if you have I/O's the water intake will still be in the water. Not sure of your drive but unless you have a raw water intake above the waterline you can't get a clean flush...

[mmwjr]

Originally Posted by Capt Al

You can buy a flush kit but the problem is that if you have I/O's the water intake will still be in the water. Not sure of your drive but unless you have a raw water intake above the waterline you can't get a clean flush...

The kit has a built in valve that closes the raw water off when hose pressure is present. I don't see any issue with this if you have a Bravo which has an engine mounted water pump but with Alphas the pump is in the lower unit and I am not sure where its water goes if this lit is used.

So question to ori is what outdrive do you have? I can't tell from the picture you posted.

[Ori Shalom]

I have a bravo 3 outdrive connected to my 6.2L mpi mercruiser engine.
that means i can just use the flushing kit every once in awhile? (we don't winterize in this part of the world...)

thanks,
Ori

[mmwjr]

Yes the kit will work just fine.