This right here ^^
Don't let ethanol gas sit for more than a couple weeks in any carbureted engine. If you fill up and know you're not going to drive for 2-3 weeks put some Sea-Foam or Sta-Bil in it and you'll be fine
There is another option at the pump in Illinois/Wisconsin, it's E-15 or 15% ethanol. Cheaper than the regular 10% swill but as you said, it comes with it's issues
I wouldn't be too hard on them. After all they are 17 and do this part time between school and sports. I would guess after that press write-up they've been pounded with work and requests
Saw a buddy this Summer take a beer can, cut a long rectanglular piece out of the can fold it over and use rtv sealant to seal it over the passage. Said he learned it from an old engine builder