Here's how our pump gas timing curve looked when we were finished. It started with a full 36 degrees under 1,000 for a smooth idle. Retard began at 1,000 rpm, pulling 25 out for a total 15 degrees advance. At 1,500 rpm 5 degrees were added bringing the total to 20 degrees advance and the curve moved up quickly to 35 degrees advance by 2,400 rpm. From there we added one more degree by 3,400 rpm then another 2 degrees to finish off with 38 total from 5,500 to peak. Try doing that with springs and weights!