Help with 1984 bayliner trophy with aq125a and 270 outdrive

vince0202

Cadet
Joined
Apr 4, 2020
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6
Hey guys new to the forums and wondering if anyone can help me. So a little history recently purchased boat (1984 bayliner trophy with aq 125a motor and 270 outdrive) and am having some issues with motor. Boat needed a lot of work to get her going I changed plugs coil wires everything ignition related and treated carb. Changed the bridge on sea water pump due to crack and changed impeller. All seemed well so I ran her with water before her maiden voyage. Idled fine and water system seems flawless. I decided to open her up a little not crazy just revved engine about half throttle then I noticed excessive smoke from exhaust. Upon further inspection noticed oil pumping into carb. From what ive read I have Blowby and im feeling pretty crappy about the situation. I did find a rebuild kit from ebay however I don't know if I can handle such a project and Marina will be out of question due to monies. My question here is What motors can I swap direct with little modification if I need to? Does this seem like a total rebuild will be necessary like could I be overlooking something stupid? Again I wanna say thanks to all and not a mechanic by any means more of a parts changer.
 

QBhoy

Fleet Admiral
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Mar 10, 2016
Messages
8,348
Have you tried holding your hand over the oil fill cap at idle ? Check for serious pressure in there ? Have you tried cleaning out the breathers ?
whats the oil condition like ? Is it fresh and not thinned down ? Is the intake manifold ok ?
 

vince0202

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Joined
Apr 4, 2020
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6
Thanks for you response I will check all things and update today. How do I clean the breathers exactly? intake Manifold appears fine. Oil is a little older was planning on replacing. What do you recommend? Should I go a little thicker? Thanks Again
 

captmello

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Jun 30, 2008
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3,852
Do a compression test first. You should have at least 150psi on each cylinder.
 

vince0202

Cadet
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Apr 4, 2020
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6
Okay compression test complete 1st 135 2nd 135 3rd 120 4th 90 so safe to say rings are shot... What motors could I use a direct swap for my outdrive 270 outdrive currently on boat?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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50,951
unless you plan on changing a lot of parts, get another 4-banger volvo just like the 125 that was in there.
 

vince0202

Cadet
Joined
Apr 4, 2020
Messages
6
found a good deal on an aq130c online will that work without modification? the only aq125a I found is like $1000 more.
Which volvo models will work correctly with my current outdrive? just wanna shop around and get best bang for buck as money isn't great at moment for shop to repower gonna have to keep it simple to do myself.
 
Last edited:

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
50,951
if you are doing it yourself. start by reading the manual.

also, start comparing motors, etc.
 
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