The push-pull cables on my CB350F will allow the throttle to close to the idle stop when the throttle is released, closing by the carburetor return spring. However, the throttle can be closed more by turning the grip slightly further in the off direction. This will often cause it to stall as the idle is reduced below the normal setting. Perhaps this is what you are doing when coming to a stop (i.e. twisting beyond the idle stop).