[capt.bob22]

Looking at a 2001 Mariah with Merc mx 6.2 mpi/320hp-- is this fresh water cooled or raw? Will be using it in salt water and leaving in a slip. Cooling / cleaning issues with the outdrive? Havent gone to see boat yet, never had an I/0, but like the looks of the boat, and they seem to have a good following, any reply appreciated. Bob

[rajjneef]

Who knows? Ask the owner. Most likely it is raw water. Most people I know prefer outboards for salt applications.

[ShabahZ280]

The cooling systems for the engine are raw water through the outdrive, unless the original purchaser opted for the closed cooling system when the engine was built. You could always add the closed cooling system to the engine, but I imagine it could get rather costly. There shouldn't be any issues with cooling of the outdrive, and for specific cleaning info, I'd talk with other boaters in your area and see what they recommend. I've always heard of a freshwater flush after using the boat in saltwater. Usually that means hooking up a set of muffs to the water intake on the drive, turning the boat on and let it run for a few minutes using freshwater to flush out all the all the salt. Another option you could go with is a neutra-salt system made by volvo penta. it's a special solution that fits inline in the water line to the engine, and has a salt neutralizing chemical. Seems to be pretty practical, but haven't heard many reviews from anyone that uses it. Hope this helps!

[capt.bob22]

who knows, ask the owner???? Now thats a helpful reply. Thought that this forum was for questions just like this. Check out the next response, very helpful indeed! Thanks for the reply, but.....who knows???

[capt.bob22]

Thanks very much for the response. Was just the info. i was looking for. Nice of you to respond. Bob.

[rajjneef]

Originally Posted by capt.bob22

who knows, ask the owner???? Now thats a helpful reply. Thought that this forum was for questions just like this. Check out the next response, very helpful indeed! Thanks for the reply, but.....who knows???

Sorry Capt. Bob but honestly nobody here would know. Closed cooling would be an option and never standard on these boats. The only way to find out would be to ask the owner. Like I said previously I would bet the whole engine is raw water cooled as I dont think I have seen a closed cooling system on a Mariah but I'm sure somewhere along the way someone ordered one with the option.

[mikeyt]

[QUOTE=rajjneef;27017]Sorry Capt. Bob but honestly nobody here would know. QUOTE]

It seems to me that ShabahZ250 gave a reasonable & helpful answer based on his knowledge of Mariah boats.

[domraga]

Suggest you change the impeller as the first job you do, closed or raw water cooling system still uses raw water to either cool the engine directly or cool the closed loop wia a heat exchanger circuit. Either way, the impeller is a very important part of the system, these engines will quickly overheat with insufficient cooling, check that impeller!

[m&mmariah]

I know noting about closed systems, so this is for my education, too. If the system is closed, it's set up like a car, with a radiator that transfers the heat from the engine, right? So then why would it even need an impeller? I thought the impeller's job was to pump the water from the lake to the engine's water pump. No need for lake water--no need for impeller?

[Zackattack]

Well, you are only thinking of half of the cooling, you are correct in that the closed system is cooled like a car with anti freeze and a heat exchanger. But that closed system needs cooled as well, in a car the air does it through the radiator, in a boat this happens through the impeller from the raw water from the outdrive and travels though the heat exchanger and then cools the anit freeze from the second system.

The difference being the raw or sea water doesnt reach the inside of the block, but is still needed to keep the system cool.