72 mecury 650 65 hp question.

[basspredator]

Hello I recently obtained a 72 mercury 650 65hp with serial number 3455210 with lower unit questions. I have been searching online for two weeks and could not find a correct answer. After searching hundreds of online threads I found this site had the best answers to questions like this.

(To the question)
I have the mercury outboard above and was wondering what lower units will fit. From horse power to years. I look around and seen that unit will fit from 1969 to mid 80's from 40hp all the way to 115hp. And some other sites stated only 72-76 with HP of 65-85. I found many others especially on eBay with no straight answers. Seeing that the threads on this site are straight forward I bring it to this thread. I have seen threads on this topic but not with my year. If there is can you please point me in the right direction.

 

[79Merc80]

Re: 72 mecury 650 65 hp question.

Hello and welcome to Iboats:

First off, your 72 should be the inline 3. That configuration and the inline 4 are completely different. The inline 4's 650, 75, 800, 850, 900, 90, 1150, 115, 1250, 1350, 1400, 140, and 1500 used the same size gear case, but different gear ratio's.

THe inline 3's used the smaller size which is the same as the 40, 402, 350, 45, 500, and 50, but again different gear ratio's.

I hope this helps more than confusses. Others with more knowlege should chime in shortly.

Craig

 

[basspredator]

Re: 72 mecury 650 65 hp question.

Hello and thanks 79Merc80.

It is an inline 3. So if I'm not mistaken from what you posted I take it any and only 35, 40, 45,50 and 65 will work. Do you have any idea what years? If I remember correctly My gear ratio on this motor is 1.46:1 from what I read. Is that correct and only from an inline 3 will work.