Mercruiser 3.0 sterndrive removed?

rich5 · May 8, 2009

Hi I own a Mercruiser 3.0 which I broke the drive shaft on the upper sterndrive from not being vigilant about watching gear lube (my first year owning a boat). Anyway I'm thinking about buying one of those Chinese sterndrive engineered sterndrives as a replacement but before I did I wanted to check that the motor is in good shape and that I winterized it properly, so with the old stern drive off and taken apart how can I
start the engine up and run it while keeping it cool?

Bondo · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

Ayuh,... Attach your garden hose to the Inlet hose on the motor...

rich5 · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

where is the inlet hose located at? What does it attach to? Would that be near where the sterndrives attaches? And would the water pressure have to come from the hose into the inlet hose or would it be good enough to get the water hose near the inlet hose and the inlet hose would suck the water through? in other words would I have to provide the water pressure?

MikDee · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

While facing the bellhousing, look for the small hole on the lower right, with a rubber o-ring around it, or a groove for the rubber o-ring, that is the main water supply to your motor, take the hose off from behind the bell housing, & attach your garden hose there somehow, then you can run your motor, Don't forget to put it back on when you're done!

JustJason · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

Ughhh... thats the hard way of doing it Mikdee....

Try this, jump in the boat and pull the engine cover off. Look for a 5/8thish to 3/4sish hose that goes in between the transom plate inside the boat and the thermostat housing. Thats the hose you want, just unclamp it from the t plate.

MikDee · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

JustJason said:
Ughhh... thats the hard way of doing it Mikdee....

Try this, jump in the boat and pull the engine cover off. Look for a 5/8thish to 3/4sish hose that goes in between the transom plate inside the boat and the thermostat housing. Thats the hose you want, just unclamp it from the t plate.

Whatever is easier Jason, Being it's a 4cyl, it may be easy to reach this, but not on a V6, or V8

Bondo · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

Look for a 5/8thish to 3/4sish hose that goes in between the transom plate inside the boat and the thermostat housing. Thats the hose you want, just unclamp it from the t plate.

Ayuh,... On the 3.0l, it's the 1 that lays on top of the manifold,+ attaches to the T-Stat housing's portside....
You need Pressure, the motor Can't suck anything...

rich5 · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

I was thinking I could just remove the inlet hose from the T-stat housing replace it with a small piece and hook up a garden hose? However what concerns me is there is a small hose that y's off of the inlet hose I would be bypassing, what is that hose? It's not listed in the manual I have? And will my idea work rather than pulling the hose off at the transom plate?

ken_23434 · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

The water is supplied by the outdrive through the connection at the transom. The water gets dumped in the exhaust and exist out the sterndrive. So, if you connect a garden hose somehow directly in place of the 3/4ish hose at the thermostat housing, all you are bypassing is the supply hose from the outdrive. The engine is getting what it needs.

Now, about the extra hose... Mine doesn't have that, so I am not sure what that is. Maybe it's the hose that leads to the power steering oil cooler? I think you just need to follow that hose and see what that extra hose connects to.

We are talking about a 3.0 WITHOUT freshwater cooling, right?

rich5 · May 8, 2009

Re: Mercruiser 3.0 sterndrive removed?

ken_23434 said:
We are talking about a 3.0 WITHOUT freshwater cooling, right?

What's the difference I assumed it's just a sea water engined cooled system, I'm pretty sure it's not a closed loop system if that's what you mean?

That small hose runs halfway down the engine portside closer to the transom. I'll have to take a better look but it appears to connect too a fitting that connects to two more hoses that you pull off with a handle.

terry dean stiltner · May 26, 2010

Re: Mercruiser 3.0 sterndrive removed?

watch your pressure do not turn on full pressure

bigskiohio · May 26, 2010

Re: Mercruiser 3.0 sterndrive removed?

make sure engine is running or you might get nwater in cylinders

Fishermark · May 26, 2010

Re: Mercruiser 3.0 sterndrive removed?

That was a year ago... I'm thinking he probably has it solved by now.

Mercruiser 3.0 sterndrive removed?

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