Craftsman 917.377151 won't start

I have a Craftsman 917.377151 that will not start. I can spray carb cleaner in the carb and it will run for maybe 2 seconds then die again. I put a carb kit in it last year. My stepson blew the carb out again a few weeks ago. It ran okay, although a little sluggish, for mowing my yard once, a week or so ago. It will not start again. It is the same problem as before my stepson blew out the carb. I use my riding mower mostly and use this push mower for getting close to the house, etc.

My stepson suggested I drill a very small hole in the gas cap to help the vacuum but that did not do any good either.

I know that it is a carb problem. Does anyone have any ideas what I should try next?

Thanks!