New spark plug (check for spark) if it runs fresh petrol, additive (outboard stuff) and ride it.
If not undo drain screw on carb bowl get clean petrol then try again.
If that fails carb off remove bowl soak in petrol over night, spray with carb cleaner maybe prod/ wipe around a bit gently try again.
Once running get it hot and ride it hard, my belief is petrol dissolves petrol deposits in time. Try it it might surprise you.
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