Great advice guys!! I have a brand new/rebuilt Carter 2100 on a 235 and it was bucking and losing power under load. I thought I had carb problems. So after reading this post, I just retarded the timing a hair since it was also pinging under load. So lilrobo, if u do the above steps and it pings, just retard it a bit. I had originally got the highest vaccum reading but apparently it was advanced too much.
