Alpha One Cooling water question

[squeak911]

Hello, I have a mercruiser 4.3 with an aplha one gen one outdrive. It overheated for a little bit this weekend. First question, What things do I need to check for? I shut it down when I seen the temp gauge at 200. I have taken the outdrive off and found the impeller was trashed. Thus the reason it overheated.
Second question, Where does the water go after it reaches the exhaust manifolds. I put a water hose on the gimble housing to make sure the flow thru the engine was good and i was expecting it to come out the exhaust bellow but instead it came out two holes on the lower part of the gimble ring.
Am I missing something?

 

[HT32BSX115]

Re: Alpha One Cooling water question

What things do I need to check for? ....................Where does the water go after it reaches the exhaust manifolds...............but instead it came out two holes on the lower part of the gimble ring.
Am I missing something?

You should check for impeller fragments that may be lodged downstream of the pump all the way to the t-stat housing......

The water comes out of your risers/elbows and dumps into the Y-pipe on a "V" engine.


Then it comes out mostly at those ports at the bottom of the transom mount. Some may make it into the exhaust bellows and out thru the prop....



Cheers,


Rick

 

[NHGuy]

Re: Alpha One Cooling water question

Are any of your impeller pieces missing? If so you ought to do a cooling system disasembly and check before you run the motor any more. The hoses and fixtures should be individually removed and either blown out or inspected. This sounds like a PITA but it beats an overheating problem from an obstruction.
The openings are relief ports, they apparently relieved your excessive water when you fed the cooling system directly.
I wouldn't even bother with the water test. Just repair the lower unit pump, hook it up to muffs and check. Then check in a tub or a lake, that's the real test. You hopefully know this but don't ever fire the engine without water or you ruin the impeller.
If the impeller is melted but complete you could check engine water flow if you feel that you must. Run the engine and feed it water at the same time. With the drive off use a cut off garden hose end in the water feed on the bell housing. The water might be stopping at the engine water pump until the engine turns, so run the water and run the engine for a better test.

 

[Howard Sterndrive]

Re: Alpha One Cooling water question

i was expecting it to come out the exhaust bellow but instead it came out two holes on the lower part of the gimble ring.
Am I missing something?

that is normal

 

[squeak911]

Re: Alpha One Cooling water question

Thanks, I have pulled all the hoses off and flushed them out.