Help identifying out-drive, Merc 165hp.

[list249]

I just picked up a project boat, a 71' Starcraft cabin cruiser. It has the mercruiser 165hp. I know the motor is a 250ci GM inline 6, but I dont know what drive is on it. The ad said merc 165hp, 188 outdrive. Unfortunately searching only find info on the merc 188hp, which is the 302ci. This is going to be a total rebuild, so i want to rebuild or replace the motor and drive. Thank you.

 

[Scott Danforth]

its a MC1, and somewhere in the boats past, someone replaced the drive (with one with the wrong ratio)

 

[list249]

wow, that was quick. So you are saying that isnt the original drive? How wrong of a ratio? Is it something that could be fixed with a different prop? Also, this is an aluminum boat, im sure it would be geared differently than a much heavier fiberglass boat? Is this still rebuildable or worth rebuilding?

 

[Scott Danforth]

the gearing comes from mercruiser to match the motor. the 302 was geared at 1.5:1 . the 250 cubic inch came with 1.65;1. gearsets are cheap. up to you if its worth rebuilding. if it was my boat, I would find a 292 and drop in place of the 250 and leave the gear ratio alone.

 

[list249]

Oh, i understand now. It just has the 188 outdrive on a 165. So its the same case for the drive just with a different gearset, and it is rebuildable. Thank you very much.

 

[shaw520]

Oh, i understand now. It just has the 188 outdrive on a 165. So its the same case for the drive just with a different gearset, and it is rebuildable. Thank you very much.

That is correct,...the 188 being a ford 302 V8 vs the 165 inline 6 will have different torque curve hence the different drive ratio.

 

[shaw520]

Gear sets may be cheap, but require some extensive tools and expertise to change out,... you'll be better off finding a small V8 or change entire outdrive to a 1:65 ratio. Changing from an inline 6 to a V8 will require a change in motor mount locations,.. some structual/fiberglass work. Im not sure but you may be able to make up the difference with a prop change,...but that'll surely leave the next owner scratching his head.

 

[achris]

As the drive has been changed, you need to check the input shaft length. The V8s and the in-line engines of that era used different length yokes. The inline shaft length is about 8", the V8s were about 9-1/2".

That decal on the drive that says 888, is just that, a decal. The drive is model 'MC-1'.

Chris. ....