Merc 7.5 to 9.8 upgrade?

[Packard8]

Hi Folks,

I have a Merc 7.5HP S/N 4550075, 1976 (?). I see that it is the same displacement (179cc) as the 9.8HP and many of the parts listed are the same.

What accounts for the difference in HP, and can the 7.5 be upgraded to 9.8?

Thanks!

 

[Chinewalker]

Re: Merc 7.5 to 9.8 upgrade?

Part of it would depend on the year. Most of the 7.5s had smaller block porting than the 9.8, designated by a sticker on the block with the word "Comet" on it...

 

[Packard8]

Re: Merc 7.5 to 9.8 upgrade?

Part of it would depend on the year. Most of the 7.5s had smaller block porting than the 9.8, designated by a sticker on the block with the word "Comet" on it...

Thanks,

This is a 1976 model and does have "Comet" on the side of the block.