I just tore it apart im missing 1 circlip guess ill replace it when I can and hopefully that's all that's wrong

 

I had a problem with the throttle not returning after I installed a new pair of grips. I found that the problem was that I actually installed the grip to tight to the end of the bar, and the end of the inside of the throttle grip was rubbing on the end of the handlebar. Which was causing it to get stuck. Took awile to figure out!!!!
Anyways, I re-positioned the grip just a hair out, and that fixed the problem.

Hopes that helps,
Shane-O