I do have a few questions on the 650 carb, since I run a demon 650dp on my 340. This is an XP , the emulsion package could be different , which changes jetting req
It was 74 square jetted? Yes
Are you using any power valves? Yes
Downleg or annular boosters? Downleg, annular don't exist in a venturi this small off the shelf
1:1 or progressive secondary linkage? Progressive but that won't matter on a dyno
Thanks for any additional info.