I recently rebuilt the carburetors on my bike after a lengthy storage period. Bike has a K&N filter and D&D slip-on. When I removed the pilot screws to rebuild, they were all at 3 turns out. I set the new pilot screws out 2-1/2 turns from bottom when I rebuilt them. The bike will fire up and run while maintaining the throttle. If I connect the manifold vacuum lines to the airbox the bike will immediately stall. If I connect them to the synchronization gauges, it struggles to stay running. I was able to maintain 1300 RPM enough to see that the #4 carb is at 5"WC and #'s 1, 2 , 3 are at approximately 6-7" WC. Throttle response is good. All vacuum hoses seem to be in the correct locations, per diagrams and manual. If I leave the manifold vacuum lines used to synchronize, the bike will run. Any ideas on what I am missing? Any help is appreciated. Thanks in advance!