Outdoor Power Equipment and Small Engines - Tecumseh 8.5hp backfire

Hi,
I have a SnowFlite snow blower with a 8.5 hp Tucumseh engine. The last time it worked it was revving really high and fire was coming out of the muffler and choke. I took apart the carb and it seemed clean. Put it back together and it now starts and stops right away, still with spit fire coming out of the muffler and carb. Also, it only seems to start if I choke it. Lots of smoke for very short period then shuts off. I am on my way to the store to buy a new spark plug for it. Any help is really appreciated.

While a quick look at it and it LOOKS clean, it is not. There are "pin holes" in the main jet that clog easily. Take it apart again, soak it, the blow everything out with compressed air.
Look very carefully for the tiny pin hole in the main jet.

Thanks indypower. I didn't notice the pin holes, so i will take the carb bowl, needles and float apart again and give it a good cleaning.

I took the spark plug out and it seems to have spark and is black (according to the tecumseh technician manual it is carbon deposit) any idea what would cause that.

I'm really new at this engine stuff. :confused: Give me a hammer and a saw instead and I'm off to the races. :)

While you have it apart again, shake the float. If you hear sloshing of any kind, replace the float as it has gas inside it and will not float. If you hear no sloshing, clean the varnish off the float as that will make it heavier.
As for the black spark plug, it is all related. Too much gas.
Tecumseh engines are notorious for floats getting gas in them.
I keep 5 in stock at all times.