Can anyone help me with information on this stern drive and hints for motor swap

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Re: Can anyone help me with information on this stern drive and hints for motor swap

so i have found a good deal on a hull with a cobra outdrive and 3.0 how hard would it be to do a complete drivetrain swap or is there a way for me to use just the motor on this boat not sure of the year i know yall said it needed to be pre 90 i guess if its after that would be my question is there a way to use it


you can use the motor if its pre-90. other than that, you could use the whole thing if you want to redo your stringers and transom to close up the hole. the cobra uses a small key-hole shaped hole just like mercruiser. the OMC stringer you have has a hole big enough to pass the arse-end of the motor thru (hence the big boot).
 

Boomyal

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Re: Can anyone help me with information on this stern drive and hints for motor swap

....careful on a swap to a stern mounted drive style. Some boats built to accept a stringer drive did not have a reinforced stern. My '75 Gulfstream stern is just a fiberglass shell like anywhere else on the hull.
 

gwgautney

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Re: Can anyone help me with information on this stern drive and hints for motor swap

ok so today i picked up a 1979 Sea Swirl boat with an omc 185 I believe that is a chevy 305. I am wanting to put 185 in my sunbird 195. Boat has outdrive on it also. My plan was to swap everything over to my boat. I have been searching the numbers 9982565 out on it and it saying it is a 400. Guy I bought it from said motor run like a top and boat was fast then he pulled motor and outdrive to redo floors in boat. When he reinstalled all that he could get was a click from the starter. My question is i thought you would need a 800 for the 185 but its bolted up just fine now I have not tinkered with it yet so I don't know what to make of it. Any ideas?? There again I may be wrong it may be an 800 and I just don't know what I'm looking at. Is there anyway to tell?


Thanks
 
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Howard Sterndrive

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Re: Can anyone help me with information on this stern drive and hints for motor swap

take the prop off and count the splines
400 use 13 spline props
800 use 15 spline props

the upper where the ID tag resides could have come from a 4 banger which will have the wrong gears in it for a V8. The lower is really where the 800 is needed for strength.

A 400 lower wouldn't last very long behind a V8.
400 and 800 uppers use the same case (housing), but the gear ratios inside are the difference there.
 
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gwgautney

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Re: Can anyone help me with information on this stern drive and hints for motor swap

Ok so I counted splines and there are 15 splines on the 185 so must have been swapped onto a 400 next question when I turn key all I get us a click at starter any ideas
 

Howard Sterndrive

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Re: Can anyone help me with information on this stern drive and hints for motor swap

bad wiring, weak battery, seized engine, seized outdrive, bad starter, bad grounds, bad solenoid, bad relay
 

gwgautney

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Re: Can anyone help me with information on this stern drive and hints for motor swap

Howard the guy told me motor sat for 7 our 8 months I cannot turn crank so what is best way to free it up I've heard diesel, marvel sea foam? And when I do that do I full it to top of valve covers I know some people don't like this idea but I don't want to sink piles of time and money and it be completely fouled up if I get it going I want to invest the time and money to make it last also about the outdrive how would I know if it was froze up prop spins last question is there a way to tell if it's in gear or not
 

Howard Sterndrive

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Re: Can anyone help me with information on this stern drive and hints for motor swap

remove the outdrive (far enough that the ball gears disengage, and retry turning engine.

Every boat sits for 7 months where I live. The engines don't seize.
 
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gwgautney

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Re: Can anyone help me with information on this stern drive and hints for motor swap

ok so i want to pull outdrive out far enough to disengage ball gears. trim is not working right now is there a way to manually lower or raise outdrive i couldn't find anything in my manual
 

gwgautney

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Re: Can anyone help me with information on this stern drive and hints for motor swap

or do i need to worry about it being down it is in the up position now
 

Boomyal

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Re: Can anyone help me with information on this stern drive and hints for motor swap

The only way you can pull it is when it is in the UP position. Have a way to support the drive, however, because you have VERY LITTLE slack in that very expensive shift cable. There is no manual way to put the wheels down or crank them up EXCEPT by unbolting the quadrant gear from the outdrive.
 

Boomyal

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Re: Can anyone help me with information on this stern drive and hints for motor swap

Ditto on the storage (non-op) duration. My boat did not run between November, last year and August, this year. And that is in a very wet and cool to cold climate (although the boat is under a canopy). That makes about 9 months and that is not too far from normal, most years.
 
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