Carb Adjust Offset Screwdriver
After taking off the carbs and drilling out the mixture adjusting plugs, I adjusted all screws to 1 1/2 turns
counter-clockwise. I bought a right-angle screwdriver (Princess Auto, $5 CDN) to adjust the mixture screws when
the carbs are back on the engine.
One minor improvement is to install a rubber washer onto the bit holder. This lets me spin the ratchet until
the bit seats in the screw head, and then I can use the ratcheting action.
From personal experience, with this kind of screwdriver you can remove the float bowl screws for
all four carbs without removing the carbs from the engine.