Yeah I actually do think it might be an air leak. Try what StrayDawg said and see what happens.
Your were 100% correct about this fix. I took the black cylinder out and put it back on the opposite side of the idle screw. It’s working now like it should. Thank you.LOL one word: Backwards. Go to the top of your carburetor and take out the little black cylinder and the long groove should be on the opposite side of the idle screw. If the long groove is on the side with the idle screw it'll act as if it's in full throttle. Or if you did not put the black cylinder in all the way it will act as if it is in mid to full throttle as well. Check both of those things!
This fix worked on my 110 cc made in China kid's quad. Replaced the carb and put the slide in backwards. Nearly blasted the thing through the garage door. Twice. Thanks for the tip patthehat033! Would have never figured that out. Runs like a champ now.10-4, I am "pretty sure" that this is not the case, but I'll check it again and let you know.