well 3 were working as normal, if i sucked on the jet i got nothing through untill i opened the pressure valve and i was able to suck air through.
But one would allow me to suck and blow air through all the time with no resistance at all.
so after testing the duff one against a good one i worked out the problem and all is fixed now
got my squirty oil can and pumped it in to the good one so it opened the valve and came out the jet.
then i tried it on the duff one and instead of opening the valve and coming out of the jet it came out between the jet body and locating dowel so i compared the 2 and basically the locating dowel had moved while i was removing them so i pushed it back in and its fine now so happy days and my £15 remains firmly in my pocket!