you really prob. just need to take the carb. off and clean it.
this is the idle hole on those smaller dell. carbs. make sure it's clean/clear or the bike will not idle.
take it all apart and clean everything, you prob. just have shit in the bowl thats causing the float needle not to seal. blow out all holes with carb. cleaner (watch yer eyes) and run a wire or guitar string thru em if need be.
there's plenty of info on here if you do some searches. or you could just spend/waste the $70 and have your 12 year old (and you) not learn anything.
good luck (edited)