Spacers on carb clamps are there for a purpose. Fasteners should be tightened until seating against spacer. The spacer also serves as a stop so someone does not overtighten these clamps causing carb boots to get cut, thus causing an air leak. As far as your issue, go ahead and tightend up all four clamps up to the spacer stops and see if this curers problem. You may have had an air leak causing lean condition due to clamps being loose. If this does not help, disassemble and inspect carb boots for cracks all the way thru the boot. Boots often show signs of cracks on the outside of the boot, but the crack does not always penetrate thru entire thickness of the boot.
Good luck!
