Alternator Belt Came Off

morebacon

Seaman
Joined
Jun 3, 2016
Messages
58
I had my boat loaned to this guy and his family and when he brought it back I've noticed the alternator belt was off. The engine/boat was still running somehow, but steering was very hard. None of the front pulleys were turning (the other belt is still attached correctly). What I've noticed is that the outboard was in the full up/trailer position as he was coming ashore and he drove with it like that, who knows for how long. Could this be the cause of the belt getting off? The belt itself looks to be in a good condition. I took the boat out one day before him with no issues at all.

How should I go about diagnosing if there's any damage, what should I be looking at? I got the manual and was thinking of trying to reseat the belt and tension it per specs, but is there anything else that could be damaged that I should check as well? There was also water and oil in the bilge that I need to track the source for. Mercruiser 3.0L / Alpha 2.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
47,618
the 3.0 has only one belt and its primary function is water circulation and the secondary function is to drive the alternator

so assume your motor was seriously overheated leading to either a cracked block or a warped head/block
 

morebacon

Seaman
Joined
Jun 3, 2016
Messages
58
I'm thinking of replacing and tensioning the belt then start her up, anything else I should do? I want to avoid doing any further damage if possible.

Also, I've changed the water pump recently, could that have helped with the overheating?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,618
you have water and oil in the bilge.

most likely your motor was overheated

do a compression test
check the oil level

then go from there
 
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