Well, I just totally overalled my carbs. I have a 70 240Z and have cleaned everything perfectly. I took off the intake manifold, exhaust manifold, the carbs all of the emmission stuff cleaned it all up and reinstalled it torqing all bolts to spec. I put in new points, pluge didt. cap and rotor and rebuilt both carbs with a standard nissan kit. I totally cleaned the carb and they look like something for a show. They are in great shape and all all likages have been cleaned and lubed. The car fired right up however it idles to high and I cannot reduce the idle speed lower that 1300 rpm. All idle adjusting screws are where they should be. the ones that are on top are not touching anything. If I tighten any of them they just increase the idle. The idle jets on bottom are turned out 2.5 turns each and it runs great however there is fire comming from the exhaust. I runs smooth but the fire worries me a little. If I turn in the idle jets out more, more fire comes out. I do not know what to do?? Can someone help me out here.