Oxymoron....?
Well, I want to help, but since they made 3 models of the GTX in that year, the carbed, RFI and DI motors, I'm not sure which one you got since "carb injected" in your description is an oxymoron.
I'll go with the idea it's carbed, since you used it first.
If your not familar with the carbs, the air box may be in your way. So, you may have to take it off. The easy way would be for you to get a small mirror (wife's makeup case,...LOL {and she's still looking for it..LOL}) and use it to look up into the carbs from the bottom. There, you will be able to see the linkage and and the idle stop screw.
It's going to be on the mag carb and it's going to be at an angle, parallel to the engine right by the locking nut to the cable. Turn it in a little to increase the idle. I do it when it's running by watching my tach and set it for 1500 rpm. :cheers:
