power washer won’t start

Subaru 3100 power washer bought a few years ago, used a few times, just once a year to wash backyard. this year it’s not cooperating, battery weak, tried hand pull, no start.
waited full battery charge over night. still no start. tried w40 spray to air intake, still no start. followed some YouTube, opened carberator and drained excess fuel. it started, yep, glad I don’t fail on these little engines, chainsaw, lawn mower, generator that I own and need for projects.
after use, followed instruction to close gas line and run until it’s out of fuel.