It's super important that your throttle returns properly; the entire system needs to be inspected in order to diagnose this issue. We'd recommend starting with the throttle pipe (aka tube) to make sure that there's no dirt, debris, or crash damage between the pipe and the handlebar - even the right side bark buster can interfere with this. If that looks good, check that the cables are properly lubed and functioning correctly (if you have any question about it, just replace them - these are fairly cheap and easily replaceable. Same for the throttle pipe!). From there, go into the carburetor to inspect that the springs, slide, and everything else is installed correctly and in good working order. If you get through all of those steps and are still having issues, contact your local dealer or a qualified, competent mechanic - you do NOT want to mess around with a stuck or sticking throttle!

I just experienced this problem on a xr250. turned out the cables were way too tight on both ends at the carb. loosened them up as they need a smidge of dead play and all is good. Ive also experienced a worn out sticky cable on another bike. As well as a broken throttle tube that was allowing the rubber grip to drag and catch on the handlebars.

'96 and 97' models are either 62\162 or 60\158 and jet needle on 3rd and 2nd groove from top respectively. 98' through '04 are 52\142 and jet needle on 3rd groove from top.