If the problem didn't exist before the filter change, suspect issue with the filter or the work performed.
On the 305, you should have the short filter with the opening pointing toward the passenger fender. Need a 5/8 flare wrench and a 1 inch open end wrench. Remove the line, open up installation point of the filter.
Make sure filter isn't turned around. The first item that goes in is a very light pressure spring, then the filter. The capped metal end goes towards the carb, the open end points to the line. If this is in backwards very very little fuel will flow.
There is also an anti leak/anti roll over safety with a check ball and spring, remove that with pair of needle nose pliers and ensure filter is installed in correct direction. Put everything back together and try to start.
