OK, lets start from scratch on carb operation in our boats. The throttle lever causes the primary throttle blades to open and go fast. When approaching 3/4 throttle, the secondaries will open due to the secondary spring overcoming decreasing manifold vacuum. Location of the throttle linkage will not affect secondary operation.......only primary operation. Secondaries open strictly by vacuum.
And stickers do indeed ad horsepower. It has been proven on the dyno.
Good Holley carb operation info http://www.holley.com/data/TechServi...ech%20Info.pdf