OK , if you are not having a issue with it removed , then I would guess that either when you are tightening the throttle up you are binding it , or you are putting it too far into the bar and do not have any side to side movement ..... when assembling the throttle , you don't need to torque it down , you just need the screws tight enough to not allow the throttle assembly to spin back and forth on the bars ......
What I would try is make sure that the cables are not hanging up on the white plastic guide , it is easy for the cable to go over the lip and it will bind as soon as you tighten things down
Then I would also take the cable adjuster on the carb , and the one with the locknut , loosen all the way , till the adjustable part is all the way to the locknut , with no threads showing , this is the first step to getting slack .... next go to the throttle assembly , and do the same thing screw in the one with the locknut , you should not have plenty of freeplay .....
Where I route the throttle cables is right between the right radiator and the frame , right at the mount , now make double sure that when you have it go under the tank , that the tank is not resting on the cable , it should move back/forth freely with no resistance .......
Tighten the throttle assembly just enough so the gap is even on both sides , then slightly tighten each one till it snugs up to the bar and you can grab the throttle and twist hard and it does not move ... if it does , slightly tighten the bolts till it is solid
If after this , there is too much slack , then tighten the adjuster on the throttle assembly only , not at the carb , snap the throttle a few times , it should snap back , do it at both extreme left and right , it should not slow down , it should still snap back
Report back with results ....
