Sounds like TM24 which has "air screw". You need to tune that style of carb starting with the pilot circuit, then the midrange and then the main jet, keep in mind each circuit is effective within a certain throttle position and has little to do with rpms, pilot from off idle to about 1/4 throttle, mid from 1/4 to 3/4 and the main is 3/4 to WOT and each circuit needs to be tuned individually and then tweaked to work with each other where they overlap. The problem with the term "bog" is that it could refer to lean or rich bog, lean sounds fluttery (almost hollow in a sense) and rich sounds blurbly, you'd probably see a belch of black smoke too. Best thing to do is adjust pilot to each extreme (1/2 turn out from lightly seated then 3 turns out) and see which way is better and which is worse to get an idea, the ideal setting is in between 1 and 2 turns out so you can make adjustments as the days weather changes but you need to have an appropriately sized pilot jet for that to work. With the needle, start rich (clip down-needle up) but lower it a notch at a time. They can be a bear to setup even when they're on the motor they were designed for but I find once it's set up you rarely have to mess with it.
