I've got a 22.5 pilot in it, and a 7dh3 needle on the leanest setting. I think a 20 is the smallest pilot, which I played with, but it starts and idles better with the 22.5. I need to play with a 7dh2 and see if that helps. I'm sure it would. It's biggest problem is from 1/8 to 3/8 throttle. It'll load up pretty bad in that range.