lower unit small hole

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
hi there I replace my lower unit because was crack, I replace the water pump on my new lower unit and the question is in the lower unit at the front of the housing is a small hole, before I never see water coming out of that small hole is that normal and what is that hole for? thanks
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: lower unit small hole

I assume you are referring to a Mercruiser... The small hole low on the front of the lower unit is a drain, nothing more. The reason your old unit cracked, was because that drain was blocked and allowed salt/ali corrosion to 'grow' inside the cavity.

Chris..........
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: lower unit small hole

and it looks like this when on the hose...

IMG_3370.jpg


next time ya go after your impeller. clean this cavity out. both the used drive i have gotten have had this cavity plum full of sand and other stuff. very hard pack.... i used a long screwdriver + a small hose attatched to my vacum cleaner.... a small wire thru the hole after ya clean it out....
 

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
Re: lower unit small hole

hi there thanks crack because I hit a rock but the problem is that I replace the water pump and when I turn the motor with the hose I have water coming out of that hole is that normal?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: lower unit small hole

Normal and a good thing... it shows the drain cavity is clear....
 

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
Re: lower unit small hole

by the way I forget to put back 1 of the screws on the water pump that will cause problems right?
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: lower unit small hole

i has only has 4. i wouldn't be happy knowing there were only 3.... this is the sorce of where the water comes from to cool your engine.... i'd go put it back if it were me.... use proper torque values on the bolts... next time, i would guess you won't forget that screw....;)
 

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
Re: lower unit small hole

yes I see is 4 I only put back the 3 and start the motor with the hose and was overheating a little bit.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: lower unit small hole

Ayuh,.....

You just Can't leave out pieces,+ expect anything to Last.....

You can either Fix it Now,...
Or you'll be Fixing it Later,....
And probably alot more than Just a Screw if you wait for Later.....
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: lower unit small hole

It doesn't matter one bit which one you forgot. It needs to be fixed before you take it out on the water.
It's just that simple.
 

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
Re: lower unit small hole

hey thanks to everybody for the help tomorrow Im going to take it apart I will take some pics and see how will work thanks.
 
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