Hello. I have a 1981 KZ550 LTD that I am fixing up. I had the carburetors apart and cleaned them, bench tested the float bowl fuel height, and did a mechanical sync. Unfortunately the two middle carburetors are dripping very slowly out the bottom bowl drains. would this be a float valve, bowl fuel height issue, or bad drain screws. I'm new to the carburetor scene so any help wold be appreciated. Thanks.