carb swap

[turbinedoctor]

I have a 1984 inline 6 90hp merc and was wondering if I can install 115hp carbs and get an extra 25 hp without damage to the engine?

I am in the process of rebuilding the engine complete with rings, bearings and gaskets, any pointers as to what I should look for or change while I have it apart?

turbo

 

[Laddies]

Re: carb swap

Carbs won't do anything to your engine or 95% of the rest of them, you 90 is ported to run at 5000 RPM or less for idle performance for fish and etc. The 115 has different intake and exhaust ports plus the 115 has piston ports.

 

[turbinedoctor]

Re: carb swap

So from what I read, you are saying that I won't see any gain from the larger carbs.

 

[Laddies]

Re: carb swap

The 2 engines use the same carb body with the same size venturi

 

[turbinedoctor]

Re: carb swap

The 90 has a WMK 41 and the 115 is a WMK 26. The only different part number I find on the two is the butterfly plate. I think the one on the 115 is larger, it looks that way, haven't measure it yet.

 

[turbinedoctor]

Re: carb swap

The more I think about it, there may be a difference in the port timing. Anynody know the difference in the port timing between the two?