I backed timing off to 17* initial and fattened both idle screws a little and it's running very smooth. I was running premium fuel and with adjusting the carb I was starting to get low rpm knocking with the 20*+ initial timing so hopefully this will cure it. I'm hoping I can run regular now without the risk of knocking, but we'll see. It also ran decent all the way down into the single digits for initial timing which is a relief as it would die before I got the carb adjusted if I went near it. It ran at 0 degrees timing too, but it didn't like it (obviously).