Logo
FULL SITE MENU

Running the Alpha 1 gen 2 stern drive without water

J

Jakwi

Member
Hey guys I'm new to boating and I was having an issue with my mercruiser where it would die when hot. It has an inlet hole line rather than muffs.

So I ran it for probably 20 or 30 min that way while carefully watching the temp.

Idle up to 1500 rpm. Turns out I had a bad coil, but now I'm worried I might have damaged the stern drive.

Should I be concerned?

Thanks for the help
 
Where was this “inlet” line or connection that you mentioned?
Was it in the engine bay as a flushing connection… Or was it on the lower unit?

Your seawater pump is inside of the lower unit and must have a water supply anytime you operate the engine. If not, you will indeed damage the sea water pump impeller and possibly the impeller housing.
 
Jakwi said:
Crap, is definitely started making noise at the end.

Is the a minor repair, or did I just try my sterndrive?
Click to expand...

First I need to know the answer to my question. Where is this inlet fitting? Is it on the lower gear unit housing..... or is it inside of the engine bay?

If inside the engine bay, you will have circumvented the seawater pump and you will have damaged it.
If it's on the lower gear unit, it should have supplied cooling water.


Running a seawater pump impeller "dry" can damaged it within 10 - 15 seconds, especially if it is very dry.
This is because water lubricates the impeller and the impeller housing.


.
 
It's on the transom and leads into the engine bay, so it looks like I damaged it. How big a job is it to repair? I'm a pretty mechanical guy and not afraid to tackle it, I'm just hoping that it is just a rebuild kit and not a whole stern drive.

Man I'm so bummed. I just can't seem to get there with this boat.
 
The good news is........ you had water within the exhaust system, exhaust bellows and through the exhaust housing within the lower unit. This means it is unlikely that you damaged any of these components.
The bad news is........ you damaged the impeller and very likely the pump housing.


Drain your gear oil and drop the lower gear unit.
The seawater pump will now become accessible.
Look in your OEM service manual for the "how to", or find a good YouTube video and watch it.


.
 
Ok, I've started looking at it in you tube, is the pump housing the part that comes with the more complete kits? Or is it part of the lower gear unit. I guess what I'm asking is if I'll need $75 in parts or thousands?

Thanks for all your help
 
thanks for all of the guidance guys. I disassembled this morning, and surprisingly the impeller is all in one piece. The housing looks a little grooved where the impeller fins contact the housing. Aside from that it all looks pretty good, I think.

Should I replace the housing because of a little grooving or is that no big deal?

thanks
 
Jakwi said:
thanks for all of the guidance guys. I disassembled this morning, and surprisingly the impeller is all in one piece. The housing looks a little grooved where the impeller fins contact the housing. Aside from that it all looks pretty good, I think.

Should I replace the housing because of a little grooving, or is that no big deal?

thanks
Click to expand...

This is entirely up to you.
We are not able to be there to have "hands on" nor to actually see these parts.

I will say that the seawater pump, the seawater path to the engine, and the temperature controlling ability of this system provides the life saving cooling for your engine.
In other words, this system is of great importance.

I'll add that the Merc A drive seawater pump incorporates an eccentrically positioned impeller design (rather than being centered and using an impeller "cam").
The A drive impellers are of rather small diameter.
They do not fair well when left within the pump housing for the winter period, causing the vanes to eventually take what we call a "set".
The vanes or blades must remain resilient and able to press against the pump body interior at all positions.

Your call!


Also, unless you know or learn about this garden hose adapter/fitting, I would consider remove it.
When flushing or testing the engine, simply use the correct garden hose water muffs, and make sure that you always have a water supply any time that you plan to operate the engine while the boat is out of the water.


.
 
Last edited:
bondo said:
Ayuh,..... Absolutely,.... If you can feel a groove, it's to deep, 'n is junk,......
Click to expand...

Thanks guys for all of the guidance. I've ordered a kit with the housing, and will be putting it back together as soon as I get it.

I'm certainly learning a lot about sterndrives this weekend!
 
Back
Top