To connect the throttle of my bike carbs I used a bicycle gear change cable. It already had a moulded on nipple at one end, I bought a solderless nipple for the other.
I drill through a bolt which was screwed into the back of the pedal box to hold the cable outer.
I then had a friend make a fitting to attach it to the pedal. This is able to rotate in the pedal.
The carb end outer is then fixed in a cable adjuster, with the nipple fitted to the carbs. I used an extra spring to get a bit more positive action on the throttle closing as I found it a bit lazy.
HTH
Dave