Small Engines (Lawn Mowers, etc.): craftsman snowblower hunting, craftsman snowblower, ring gasket

Question
I purchased a craftsman snowblower model # 247.887900 last year and it ran great. This year at idle the engine is pulsing or hunting until it is under full load of a lot of snow. Also while it is running it back-fired every so often and it looks like flames in the muffler.
Any suggestions to resolve this issue?
Thankyou,
Jake

Answer
Jake
If the Engine idles roughly, unevenly, or surges your Possible causes may be the following:

1. Carburetor is dirty.
2. Air leak in carburetor or intake manifold (e.g., bad O-ring, gasket, primer).
3. Carburetor is improperly adjusted or needs service.
4. Fuel line or fuel tank cap vent is clogged.
5. There is water in the fuel.
6. Fuel pump is defective.
7. Governor is not set properly, sticking, or binding.
8. Loose carburetor/intake pipe resulting in vacuum leak.