First, I'd double check the condition and routing of all hoses and such. You know, just in case.
I'd then proceed with a good side-by-side comparison between the parts diagrams and the actual carb parts, especially checking for something missing, especially something tiny and easily overlooked. While going through the carb again I'd carefully and patiently inspect each and every component for contamination or defects. I'd exactly follow the directions in the repair manual for reassembly, double double checking adjustments, alignments, and torques.