Holley issue

4160 750cfm vac. sec.
Secondary plates always wet, primary dry.
I`m thinking this is why I get a backfire on cold starts.
Float setting seems good.
Anybody ever have this issue and figure it out?
I thought it was dripping from boosters, dabbed with paper towel pieces and dry?
Laced a strip across under both and checked after a few hours and dry...
How/Where, else could fuel keep the secondary plates wet looking all the time?
I cant find any sec. metering block cutaway views to help diagnose.
Thanks