Outdoor Power Equipment and Small Engines - 27 hp Kohler Carb Upgrades

I have a 27 hp Kohler motor on my ProDrive boat motor
(ProDrive Shallow Water Outboards)

and am trying to get more power out of it. I've been trying to find a better carb for it as well as better air filter to go with the new carb setup.

Can anyone here help me?

I have no idea what it is you have for a boat as I'm not familiar with them and would seem to me that there must be a web community out there that may have ideas for you that are in the same boat. <Cute huh? ...same boat, boy I kill me. And although I'm in the small engine business and have a good amount of racing background (only on dirt and snow) I know of no performance upgrades for Kohler engines. Keep looking, I'm sure you'll find what you're looking for. Hey, got any pics of what you have?

I just searched what you have and I see this is not necessarily a performance/competition engine as the three available power options are simply stock Briggs and Kohler engines. Since, apparently, you are not intending to modify or otherwise race these, the stock carburetor should give you all the useable power you need and perhaps you have a carburetor in need of a good cleaning and reconditioning. Post back with your intended use, your trouble being experienced and the exact model, specification and serial numbers of the Kohler engine.