A weft yarn insertion apparatus for a weaving loom, the apparatus including a main fluid nozzle for inserting a length of weft yarn into the warp shed, a pair of nip rollers, for positively feeding the weft yarn into the main nozzle, the nip rollers being located immediately upstream of the main nozzle to enable the nip rollers to propel the leading end of the yarn through the nozzle and into the shed, and a weft yarn guide immediately upstream of the nip rollers, the guide being movable to selectively introduce and withdraw the weft yarn beteween the pair of nip rollers. The rollers are driven so as to project the weft yarn into the shed at a speed in excess of the given speed normally imparted to the yarn by the main nozzle when the yarn is introduced between the rollers. When withdrawn, the rollers permit the nozzle to project the yarn at the given speed.