Questions on early 60's Mercury 100 hp

AK2boats

Recruit
Joined
Jun 3, 2012
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3
I just purchased a 20' 1960 boat, that is in excellent condition, and would like to keep it as original as possible. It doesn't have a motor on it yet. I also found a couple old 100hp Mercury outboards, they are listed as early 70's but the picture is of an early 60's motor. One is a short shaft, being sold as running. The other is a long shaft, runs sluggish, being sold as parts. Not being familiar with outboards I have a couple questions. First - can the rotation be changed, so that one can be counter rotated, to use as a pair? And second - What would I need to change the short shaft to a long and are the parts available? Thanks.
 

79Merc80

Senior Chief Petty Officer
Joined
Nov 22, 2007
Messages
673
Re: Questions on early 60's Mercury 100 hp

As far as I know, none of the inline 6's were counter rotating. As for the second issue, if your boats transom is 15", then just mount the short shaft and have fun. If your transom is 20", you can take the powerhead off of the short shaft and put it on the long shaft's exhaust tower, then bolt it on and go.

Shouldn't need any special tools/parts to do that swap, as long as they are the same vintage. The 1000 (100hp) came in 99.9cid, and 89 cid, and they can't be swapped.

Hope this helps,

Craig
 

AK2boats

Recruit
Joined
Jun 3, 2012
Messages
3
Re: Questions on early 60's Mercury 100 hp

Thanks Craig,
I figured on swapping the long shaft to the running powerhead for now, then rebuilding the other one and finding a long shaft for it. I didn't know if you could reverse engine rotation, like inboards, so I could run twin outboards. I'm thinking I will need around 200 hp on this boat anyway. I know that the newer engines would be more efficient, but a pair of restored Tower of Power engines just looks too sweet,and would keep it classic.
 
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