If you are putting a hot foot in then I would just pull the old throttle cable out of the loom and tiewrap it in the bildge area. That way if you ever sell the boat and the new owner doesn't want the hot foot they can switch back. It won't affect your ability to shift it into gear.

That is what the dealer did for the previous owner to my boat but I didn't like the hot foot so I took it out and the cable was there for me.

As for adjusting since it is a carb motor all you need to do is when the hot foot is all the way up the butterflies need to be closed and the throttle linkage needs to be against the stops. When you press down on the foot you need to adjust the back screw on the foot to all for the butterflies to open up all the way 90 degrees in the carbs. That is full throttle.