Hi, if the cable is good, I would remove the carb, unscrew the top off the carb and check to see if the slide (#8 in the picture) is caught on the guide pin inside the bore. This often happens when the carb is reassembled, but can also happen if the top was not tight and the throttle was pulled hard. If you find the slide caught on the pin, check for wear or damage that could cause this to happen again and repair as necessary. If there is no damage, let the slide down and make sure to recap the carb tightly.
If the slide is not caught on the guide pin, check for free motion of the slide. Pull it out and inspect the slide and its bore for wear, dirt, and scratches. If it's only dirty, clean it up with carb cleaner. However, if there is wear or damage that can cause the slide to stick in the bore, replace the carb.
Please let me know if you have more questions, and thanks for using FixYa.