Outboard Question!?!?!?

[SKRAMER]

Can I Convert My Johnson V4 Outboard from 90 hp to 115 hp Just by changing the carbs to the 115 hp Carbs?????

[dd24skater]

I'm not sure on that one, what are you trying to do? Is 25hp really going to make that much of a difference?

[Davidmnc]

I am pretty sure the reid (sp?) valves have to be changed also. But i am no expert by any means.

[Davidmnc]

I'm not sure on that one, what are you trying to do? Is 25hp really going to make that much of a difference?

Over a 25% INCREASE! Hell yea it would make a difference.

[DonziGirl]

Outdrive Man, or Twin OB Sonic would know for sure.

[Twin O/B Sonic]

Can I Convert My Johnson V4 Outboard from 90 hp to 115 hp Just by changing the carbs to the 115 hp Carbs?????

I know V-6's way better and know the difference between a 200 & 225 is carbs only on the loopers which I'm guessing your V-4 is as well.
Easiest way to be sure is to go to the BRP parts site and look up part #'s for the 90's and 115's. If the part # for the bare block is different then you can assume the porting is different as well.
http://epc.brp.com/SiteMods/BRP_Public/BRP_Public_Login.aspx?ReturnUrl=%2fIndex.aspx
Guessing here but I'd think 90 - 115 to be carbs only but from there to 120/140 to be porting.
As to the reeds, I'd be shocked if they were different but have heard that some had the reed stops closed up on the lower HP motors and opened for the larger ones which would be an easy fix.
If you have the older cross flow motor then it and the 115's would have the flat backed block/exhaust chest where the bigger one's would have the bubble back block.
Hope this helps.