Fill tank with fresh mix.
Gain access to carb air inlet. With choke open, spray in a good,
wetting dose of Gumout. Close choke, and let it sit for maybe 15 min.
Try to start & run, as you normally would.

Meanwhile, fuel lines may have been deplasticized, diaphragm
cracked/leaking.
May need repairs or professional help.

HTH,
J