Check the install of the float valve, they can be a pain to seat properly.
It doesn't matter how you nymber the carbs, the bike can't count and it can't read either, but just for info: LF #1 LR @2 RF#3 RR#4. Look at your throttle cable and check which carb it goes to, that would be the base carb, next is the one it's mated with and in this case it's the one in front of it. Then check the linkage to the opposite bank to see which one is linked to the base carb, leave it for now but balance the last carb to it first so that both those carbs are sync'd, then balance the linked carb to the base carb. Now that that is done, do them all again once more. Everytime you make an adjustment, blip the throttle so that all linkages seat back to where they think they should be. The throttle blip has nothing to do with clearing the carbs or engine, as much as it has to do with proper seating and positioning of the linkage. Once this is done the only thing that might throw off the sync is worn linkage or obstructions in the carb throat,,,,, or leaky valves maybe.