First thing's first? What kind of bike? Are your idle/mix screws set correctly? My old Blast died while idling too. Figured out the PO installed the new carb but never bothered to set the idle screw. A little bit of turning and viola, idled perfectly.
What kind of bike is it? Most bikes will have an idle adjustment knob located on the side of the bike or on the carbs. I may be able to tell you if you have an adjuster or not once you give some more information. When you turn the knob to the right/clockwise it raises the idle, left/counterclockwise lowers the idle. Most bikes are around 1,100 rpm, but yours may be more or less depending on what your manual says for your model.
Sorry, I don't have enough posts yet to show you pics. Google motorcycle idle adjustment knob and look at the images, some will have them pointed out or circled.
Try not to mess with the air and fuel mixture screws and take a GOOD look at carb when working throttle,
most likely you will see a part where throttle cable is hooked to and has a screw with a spring under it,
twisting screw to right could increase rpm, or so I remember on my S&S carb.
Yeah the bike is a motorhispania rx 125r so it's basically impossible to find a manual or anything for it, I'll just pull out the fairings and then try the throttle cable attachment trick like Ray'ssporty1200 said if that doesn't work (probably will I mean if it stays stable when I give it a bit of throttle) if not I'll just mess with the air and fuel mixture screws if I find them xD mine definitly idles around 1.5 since it's dying at about 1.3,
hopefully it works xD (dumbo mechanical skills here)