There could be a couple reasons for a sticky throttle. I would check the most obvious first. Make sure your grip has not slid down any and is contacting the bar end. I usually trim a little off the end of my grips to ensure this will not happen. If that is not your problem you may have to lube your cable. You can buy a cable lubing tool that clamps onto the cable and shoots lube down into it. These can be purchased at nearly any motorcycle shop. You may also need to adjust your freeplay in the cables as well.