mercruiser help

[Audiohype]

hey guys i bought this boat a couple weeks a ago 75 cobolt anyway tokk it out and it seems to be running warm not really hot just the temp .. so anyway ive been reading the forum and discoved might be the impeller so i call the local parts store and they tell me there is no impeller in the outdrive the water pump on the motor does all the work it has the 233 mercruiser engine witch is a 351w motor im gonna change the theromostat but just want to see if this information is correct or if i need to go elsewhere? im also gonna try a new gauge hopefully one that says the actual temp not just green and red

 

[Don S]

Re: mercruiser help

What outdrive do you have?

 

[Audiohype]

Re: mercruiser help

i was told its an alpha type or alpha 1 i honestly dont know only markings on it are mercruiser 233 and other mercruiser emblems serial # is half gone on it

 

[Haut Medoc]

Re: mercruiser help

There is an impeller in the drive.....
& it is what supplies cooling water to your engine, not the engine circulating pump that cools the block once the water is there......
The temp gauge you describe is very accurate, & if you are in the 'green' you are OK......
I have the same style gauge & it works just fine......
Change the raw water impeller in the drive if you are running warm.....
Here is a link that will be helpful with that task....
It is not the exact manual you need, but it should suffice.....
Run the cursor over the letters on page seven & click on the part you want to view........
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf​

 

[Don S]

Re: mercruiser help

Actually, you have a Mercruiser "One" drive. That was before what is known as the pre-Alpha drives which were the R's and MR drives. The R, MR, and Alpha drives were in Service manual #6 that haut linked you to. The manual that covers most of the "One" drives is manual #4, but it only goes back to 1978. What you need is manual #2. This manual covers both engines and drives in the same book for everything from 74 thru 77.