On my F4 the throttle don't return to de-throttle position. Can anyone tell how the throttle adjustment screws are set. Does the top throttle cable setting is all the way out or in? What is the bottom throttle cable set as?

 

Are they clean? If its sluggish than they are probably dirty, if the grip just stops than you need to take off your tank and adjust the cables from there. You need to adjust the cables so there is between 2-6mm of free play at the throttle grip.

 

Also check that the throttle tube isn't being held up by the grip rotating in contacr with the bar end. Grips come in different lengths and sometimes they're to long for the throttle tube.