[Tommy]

bkozlow's post reminds me that carburetors with mechanical secondaries require more nuanced operation by the driver than standard street carburetors with vacuum secondaries. Their advantage is that they can give full open throttle quicker than vacuum secondaries but require the driver to control the rate of opening and closing to manage the air/fuel ratio during the transistion to and from wide open throttle. IF you have limited experience with a carburetor with mechanical secondaries your solution may require little more than adjusting your throttle technique to match your hardware. In other words, think of squeezing it more or less rather than flipping a switch from off to on.