Mercruiser 3.0 freeze plug locations

dyarumian

Cadet
Joined
Jun 27, 2005
Messages
9
i bought an 86 mercruiser 140 hp with an alpha 1 stern drive. i found 2 places for the freeze plugs on the port side of the engine but it still leaks from somewhere in the back cant quite seem to find the source yet, is there another plug in the back of the engine or is something leaking?
 

speedholes

Seaman Apprentice
Joined
Jun 14, 2006
Messages
31
Re: Mercruiser 3.0 freeze plug locations

There is one behind the flywheel on the back. Pray it's not this one, as it means removing the motor, then taking the flywheel off. Start motor on muffs and see if water is leaking from the back, between the block and flywheel. That is the only other one I can think of right now.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 3.0 freeze plug locations

Are you sure the water is coming from the engine and not the drive? A bad ujoint bellows would allow water into the boat from the transom shield. Has nothing to do with freeze plugs.
 

dyarumian

Cadet
Joined
Jun 27, 2005
Messages
9
Re: Mercruiser 3.0 freeze plug locations

it could be that the boat has been sitting since 99 and it looks like allot of stuff is dry rotted. can i just call up a boat yard and have them order the part or maybe even get them to replace it?
 

uaw9fan

Petty Officer 2nd Class
Joined
Oct 25, 2005
Messages
112
Re: Mercruiser 3.0 freeze plug locations

This time of year? You might see your boat back around october
 

dyarumian

Cadet
Joined
Jun 27, 2005
Messages
9
Re: Mercruiser 3.0 freeze plug locations

yeah no kidding. so does anyone know whats involved doing it your self. will i have to pull the motor?
 
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