I am taking advantage of the time of year to sort out some niggles and I have a question. I have a lot of play on the twist grip when the throttle is closed and trying to figure it out. Between the second and third carb there is a screw with wire suggesing it shouldn't move, The screw does not touch anything. Under the screw there is a piece with a spring each side. What does the screw which does not touch anything do? It is almost like it should thouch the point of the piece below as a stop. Sorry about the basic language I don't know what the bits are called.