okay guys just picked up a 1999 lt80, it starts right up everything works as it should really like this quad............except:

I am trying to adjust the air/fuel mixture aswell as the idle and on this stock oem lt80 carb there is a flat head adjustment screw on the foot brake side of the carb? BUT also there is a phillips head adjustment screw on the bottom bowl of the carb facing the left side of the quad (oppesite of foot brake side) whats this screw for?

I have not touched the phillips head screw on the bottom bowl of the carb but I have tried to adjust the flat head screw on the foot brake side of the carb and I noticed when I back the screw out enough the quad will idle down the father the screw is backed out an also that with this screw backed out pretty far if I give the quad more then just a little bit of gas it will bog down and die unless I lift off the gas quickly then it will idle.

Everyone tells me there is no air/fuel mixture screw on the lt80 but what the heck am I messing with then because its not just a simple idle screw or else it wouldn't bog

 

It IS the idle adjustment. LOL
The bottom screw is a drain for the carb bowl.
Maybe a plugged jet making the bog.
Maybe check the compression.