Will 1983 mercury 25hp lower unit fit 1987 model?

clintb

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Feb 1, 2004
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7
I have an 1987 mercury 25 horse short shaft with a blown lower unit. I found a lower unit for a 1983 model. Will it fit?<br /><br />Thanks
 

mellowyellow

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Jun 8, 2002
Messages
5,327
Re: Will 1983 mercury 25hp lower unit fit 1987 model?

welcome aboard,<br />I THINK it will fit fine, but to be sure I would<br />check with a local merc dealer.<br />good luck,<br />M.Y.
 

WillyBWright

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Dec 29, 2003
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8,200
Re: Will 1983 mercury 25hp lower unit fit 1987 model?

I'm going by memory, I don't have any books here. I'm thinking there was no 25 Merc in 1983. I think they were still making the old 20s (Originally 200s). If that's the case, then definately not. I'm not sure what year they started making the 25s. As long as they are of the same design then probably yes, as long as you don't mix short and long shaft models. Even 18Hp and 20Hp gearcases would fit a 25Hp of the same basic design.
 

clintb

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Feb 1, 2004
Messages
7
Re: Will 1983 mercury 25hp lower unit fit 1987 model?

thanks for the input guys. i need to revise my post. the older lower unit is from an 18 hp mercury supposedly 81-83 years. it looks just like the 87 mercury lower unit. are there any differences. i have heard that the shift rod could be different, maybe it is longer or shorter.<br /><br />thanks
 

WillyBWright

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Dec 29, 2003
Messages
8,200
Re: Will 1983 mercury 25hp lower unit fit 1987 model?

I think it would work. I wish I had access to a parts manual right now. If the shift rods are different, it should be an easy swap.
 

Stefan Schmitt

Seaman Apprentice
Joined
Jan 3, 2004
Messages
46
Re: Will 1983 mercury 25hp lower unit fit 1987 model?

Goto www.mercurymarine.com - then goto "Products - Outboards" and then click on the "Parts Express" link - Make sure you have your serial number, and that of the lower unit's engine. Type those in: You will find exploded diagrams there you can compare.
 
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