Carb adjustment is an owner/operator procedure done on a boat, on the lake. Unless somebody has totally screwed it up. In that case you begin with 1-1/2 turns out from lightly seated on the slow speed needle and 3/4 turns out on the high speed needle.
I figure when you buy something like that, assume there is something wrong with it. The game is to figure out what that something is. I also figure the guy's statement about adjustment, along with $1.69 + tax will buy you a small cup of coffee at the corner gas station.,