i just bought an 1984 sentra and i'm running into a problem where the engine revs super high during idle and driving(idk how high exactly, tach doesn't work), high enough to power through the breaks(i used the e-brake to stop). this is my first carb'd car so i'm not familiar with them at all. i've googled for ways to fix it but cant really find any clear answers, or even a properly labeled picture of the carb. i have found threads about an idle screw but i haven't find where that would be or how to differentiate it from all the other screws in or around the carb. does anyone have a picture of the idle screw on the carb? or know how to solve the issue?