it is all standard mc2 , they sell 3 needles for this type at Burlen , rich , normal and weak , the nut is right up so in its weakest position but when the slide is lifted it does not try to cut out as I would expect but picks up , I have two on my MG . I will try the weak needle , the bike starts like no amal fitted triumph ever has . choke on first kick but ticks over too rich