It hapened to me twice. It was the main jet dirty.
You have to loose the 2 carburator clamps, turn it 90 degrees to have acces to the lower part of it. Then remove the float bowl cap, and finaly remove the main jet and clean it. Mine had a small piece of wood once, and dirt the other time.
I will put you on a link the instruction to take the main jet out (with pictures) that i folowed when i did it.
WoodWarrior.com :: View topic * HOW TO * Change the main jet in your Wolverine 350
good luck,