Something I went through
I have a postie. When I first set her up I used the throttle cable that came with the postie carb as I also used the postie throttle grip.
This postie carb is quite a bit smaller than the Mikuni I put on and the postie throttle grip had no right angle turn in it so on closer inspection I could see the postie cable was a lot shorter.
I figured out after awhile that this was stopping me from fully pulling the slide open in the carb as when I turned the throttle the cable would be fully wound up but it only would have opened the throttle a bit over half way.
So ... what I would do ... is get a throttle cable and a brass/steel end nub for it ( you can get the little nubs from bike shops for like 50 cents and you just solder it on )
Then I would work out where you want the slide in the carb to lift to and shorten the end of the throttle cable to suit then solder the end nub on.
Then when you want to go back to it being normal you can just swap the cable back over to a normal length one. You probably wont need to take much off the end. Maybe 1-2 cm.
You will need a good pair of solid clippers to cut the end off the cable so you get a nice clean cut. Then you pull the nub on. They have a little hole in them. Then you solder the bastard. They take up heat really quick. Make sure when you do it that you leave a small bit sticking out the end. When your done with the solder clip this end bit off. It is also important not to get any solder on the brass it might lock up the throttle grip. I did this and made a bit of a mess and then I had to spend awhile sanding it smooth after.
ALSO ALSO ALSO make sure that you do the throttle grip end not the carb end !!!! as the last thing you want is for the tiny nub on the carb end that is under tension from the carb spring to fall off and make its way in to the motor!!!
Hope that helped ...
