Evinrude 31.8ci Mod Advice

[JohnsonM50]

The Mikuni slide carbs will probably perform better to start with. I made up a manifold to accept a 2 barrel carb from an OMC 85hp. Each barrel the same size as the stock single. Each cylinder draws from one barrel so it won't double the fuel requirement. It draws the same amount of air thru each barrel at half the pulse rate per barrel out of a common float chamber. No need to syncronize. This gave more mid range power but was not faster on top.

I also see in the pic that you set this up as a 31.8 manifold. [clever]