How is the cooling system on my 4.3 mercruiser I/O supposed to work?

[jwtrs68]

Hello, I'm new to boats and inherited this wonderful piece. I don't know the year of the boat. it says "Winner" on the side. LOL
The water pump was halfway removed when I got it, the oil was BLACK and the power steering pump was leaking. I changed the water pump, fixed the power steering hose, changed the oil and got it running. The thing overheats. I don't know why. The boat sits in a sling which is where I have been working on it. Water seems to be circulating and the engine seems to at a at a normal tempature untill I try to go fast. at that point it overheats rather quickly. please help. the engine and cooling system looks like this:
Any help you are willing to give would be greatly appreciated.
JW

 

[alldodge]

Re: How is the cooling system on my 4.3 mercruiser I/O supposed to work?

Hello, I'm new to boats and inherited this wonderful piece. I don't know the year of the boat. it says "Winner" on the side. LOL
The water pump was halfway removed when I got it, the oil was BLACK and the power steering pump was leaking. I changed the water pump, fixed the power steering hose, changed the oil and got it running. The thing overheats. I don't know why. The boat sits in a sling which is where I have been working on it. Water seems to be circulating and the engine seems to at a at a normal tempature untill I try to go fast. at that point it overheats rather quickly. please help. the engine and cooling system looks like this:View attachment 229712
Any help you are willing to give would be greatly appreciated.
JW

:welcome: to iboats JW

Did you change the impeller in the drive?

What is the serial number of the engine or at least the year

 

[Bt Doctur]

Re: How is the cooling system on my 4.3 mercruiser I/O supposed to work?

see if this helps http://www.boatfix.com/merc/Techbk/97/97hga6.pdf

 

[Bondo]

Re: How is the cooling system on my 4.3 mercruiser I/O supposed to work?

Hello, I'm new to boats and inherited this wonderful piece. I don't know the year of the boat. it says "Winner" on the side. LOL
The water pump was halfway removed when I got it, the oil was BLACK and the power steering pump was leaking. I changed the water pump, fixed the power steering hose, changed the oil and got it running. The thing overheats. I don't know why. The boat sits in a sling which is where I have been working on it. Water seems to be circulating and the engine seems to at a at a normal tempature untill I try to go fast. at that point it overheats rather quickly. please help. the engine and cooling system looks like this:View attachment 229712
Any help you are willing to give would be greatly appreciated.
JW

Ayuh,.... Welcome Aboard,... What year does the Registration say it is,..??

My guess is, ya burnt up the impeller in the drive, No water flow,...