I should charge you for this because it cost me $950 for the dyno to find out
I have a new 540 Dart motor I put on the dyno for a day with a BG Marine 850 mighty demon. we broke the motor in but couldn't get the carb right - see utube 540 - anyway
too rich in low RPM to lean high - found the boosters were too small and only Barry Grant could fix ( the jetting couldn't fix the problem because the boosters were too small) only issue Barry Grant went out of business the day we we were on the Dyno. Jeg's came to the rescue and traded my BG for an 850 Holley marine. My BG 850 was a down leg mech secondary carb - beautiful compared to the Holley but crap as a carb.