The reason I asked about the HS needle is that I was surprised how little, if any adjustment was needed when vastly different props are tried. I individually set 3 different props, a 22x8, 22x10, and a 4-blade 20x10x4, and they all used the same needle setting even though there was a 2K difference in top rpm. I had assumed that rpm differences would dictate different needle settings, but apparently that is not the case. All required 1.75 turns on the HS needle.It seems the difference of props is not the issue; it is having the engine putting out max power.