Won't start. Gas line was rotten so I replaced it with one I got at the hardware store. A little larger OD but fits the port at the engine. Before it would start but wouldn't stay running. Now it won't start at all.
Make sure the "new "line is not kinked or pinched off.
Next see if you have spark, and then check if you have fuel.
(You should be able to see if it has fuel by pulling the spark plug.)
I'm betting the carb has some dirt, varnish, or tiny pieces
of old hose stopping it up.
I'm betting the carb is the source of your problems.