I have a datsun 1200 gx coupe with a a14 head, had some problems with the standard hitachi downdraught carb, so i removed it and installed twin dellorto 40mm carbs on a well ported manifold wit the rubber fittings between the carb and manifold, it's got 58 idling jets, 7772.8 emultion tubes, 210air, 130mains and 32mm chokes. it's revs up fine but cant seem to get it to idle on all the carbs, if i pull off the cyl 3&4 plug wire it idles exatly the same, which tells me it's not idling on the back carb. it's got original (in very good condition) links between the 2 carbs. it's not spitting back and revs up perfectly but no idle