I have a 20 year old lawn mower with a bagger I can't find the model number of the mower but I know it's engine is a Briggs and Stratton 407777 E1. It run great has a new fuel pump and new lines except the line from tank to filter including the filter need to be changed soon. It runs great but the fuel filter slowly drains and starts to pop and sputter require more and more choke then ideals at about 70% choke and I disconnected the line and blew it out with air while it was empty to make sure I got dirt out but it started great and drained the filter again. I think the hose collapsed fromm the tank but any ideas would be helpful. I put picture but it's drain it so it ends up sipping it and coughing and sputtering.