Carter BBD tuning issues

if it is big and low, like 1/4 inch, its a power brake vacuum line. just plug it if you dont run PB's. you need a vacuum tight intake for a carb to work decently. if its high, its likely a bowl vent or some other BS that can be capped but it wont affect driveability as its above the butterfly of the carb. Choke is vertical when off, straight up and down. sounds like your choke is just out of adjustment. look at spring and check for a screw, you can turn it to alter choke position. I believe you want to turn it so the coil is looser: a cold spring wants to wind up, a hot spring wants to relax.