I bought a tool in the blind going by a motor cycle vendors description thinking it may work to adjust the rear carb on 6pk engines. Well as it turned out, he lied just to make the sale. I sat down tonight and modified the tool. I figured I had nothing to loose since it wasn't doing me any good and it cost me almost 40 bucks to get it. It isn't perfect, since I just modified it and tried it out to see if I was doing any good and wellah----------I can adjust my air mixture screws now on my rear carb. I installed the promax billet blocks already, so I am able to jet the outboards now to better tune the system. I really didn't want to spring the bucks for their throttle plate, so this was a major step for me at 1/5th the cost and made the system a lot more easier to tune. I will start tweaking this tool more and making it more user friendly for others. But for now, I am pleased with the results. The tool is 17 inches long so you don't have to be right up into the engine. It has a 110 degree bend with a 1 inch long tip and it is extendable, even has a screw driver type handle grip to twist with. It has a flexible inner shaft with a flat tip on the end . The outer core is rigid tough, and you can feel the pressure on the air mixture screw when you engage it.
I started the engine cold after the initial set, and immediately noticed better idle and throttle response. This is a major step forward for tuning , when you start stepping away from original cam specs, and going to a larger cam with different demands on fuel mixture settings.