Could be idling quite rich. Do you have a wideband?I was able to scrounge up some 130 mains, 180 air correctors, 32mm chokes and a range of idle jets. Currently I have 50F9, 55F9, 55F8, and 60F8 idle jets.
So far it idles fine but I noticed something odd, it runs about 15-20 degrees cooler than with the SUs at idle. Any reason why this would be?