Go buy yourself a $10 - $15 Crock-Pot and and some Antifreeze and soak the engine in the antifreeze in the pot overnight on low heat.

Remove and rinse with clean fuel and it should be as good as new.

You may want to remove the Carburetor and just let it sit in some fuel overnight instead of putting it in the crock-pot.

Please do this in the garage or outside in a shed away from your living quarters.