if the pickup is plugged you can clean it by pulling out the sender, but if it's that plugged, it'll mean the tank hasta come out and get cleaned out - I'd suspect more likely it's your fuel filter getting plugged again if you've got a rusty tank - check it - pull it off and blow it out backwards if you can, and check if there's a built in filter in the carb inlet that could be plugged - could also be something has messed up in the carb, like plugged or stuck float
Bill