Re: Motor bogging at start up low speed
BTW- It sounds like you are using the cable adjuster on the top of the caerb to pull your throttle cable up. The correct way is to adjust it so there is "just free" amount of play in it. In other words when you pull up on it, you should just perceptably feel it move.
The scrwew on the side of the carb is for adjusting idle speed, and speed alone. There is no mixture screw.
I also second the motion for you to move your "C" clip down one notch on the needle, and check the plug after a few miles.