My 306 is surging at idle. Between 500-750 rpms. Its got a demon 650 carb. I was told by previous owner that the timing is set at 10 over. Doesnt die on me, it just surges. Itll surge, then equal out to a idle of roughly 550rpms. Then it surges again. I know the idle could use a bump to 750-800 rpms. Hopefully thatll fix it.