I'm trying to dial this XP in after having the engine rebuilt. Did a complete rebuild on the carbs, including N/S. Pop off was 21 psi. Low speed screws are set to 1 1/4 out. Everything on this is stock. It completely bogs down until it stalls if I give it some throttle. I made it 50 feet, it stalled, and I restarted to idle back to the dock. After I restarted I couldn't give it any gas without it wanting to again just bog down. I'll pull the carbs again to ensure everything looks good but I'm at a loss. What else can I check or where should I start?