The fuel mixture isn't correct. If your main jet is adjustable, turn it in or out with the auger and impeller turning to put a load on the engine. Start 1 1/2 turns out from light seated position. Adjust from there.

When that is close to a good run, put the carb at idle and immediately throw it up to full speed. Does it stumble? Turn the idle air screw in or out a bit from 1 turn out from lightly seated position. When you can go from idle to full speed with minimum stumble, then make a final adjustment to the main jet.

If neither of these things work, then your carb isn't clean inside.

See these pictures below:

From time to time the question is asked about why an engine will not run long, or smoothly, or will start with starting fluid and not continue to run. The problem is usually because of a blocked or constricted jet. The small ones are easy to miss.
Shown are 3 of the typical jets and the small holes. All 3 are Tecumseh jets. Briggs jets are similar with the center-bottom hole and one on the side. All these holes need to be fully clean and open for the engine to run correctly.
Some jets only have the center-bottom hole.

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See also this posting:

http://forums2.gardenweb.com/forums/load/lmower/msg061726346162.html

i tried everything that you recomended and i still get a flame coming out of the muffler?

Aside from buying some marshmellows... Is it popping and throwing flame? One may think that the flywheel key may be partially sheared or that the valves aren't seating as they should or may be sticky. They didn't have much of a muffler to prevent afterfire from lighting up the night.

you were right, it was the flywheel key.

thanks for your help.

sorry to bother you's again but with all of the taking the carb apart and resetting every thing i can't get it to idle down,

when i turn the idle screw in the speed doesn't change,i can turn it all the way in and it doesn't change.
i reajusted the govener, and it still won't idle.

any suggestion?

Are you turning the idle screw or the idle air screw? The latter is hidden inside the carb.

i am turning the one on the out side and on the side of the carb.
i'm not sure where the one on the inside of the carb is?

In this picture, the idle speed screw is the rusty one on top of the carb. The one in the side of the carb is initially set to 1 turn out from bottom.

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i have tried the one on the top which i believe is hooked to the govener rod, but it runs fast or sputters or it shuts down, maybe i have the rod or spring in the wrong holes?
does it matter which holes the rod or spring go into?

It sure does. If you look closely, you'll see wear marks where the rod used to be. Only one hole is ever used, so look for wear.

I've always wanted to ask this question and it seems appropriate here. If only one hole is ever used on the throttle plate or choke plate, what are all the extra holes for?

"what are all the extra holes for?" Whistling!
It is just the engineer's way to get the metering correct and to direct the flow through the venturi. An example of re-engineering comes courtesy of Kohler this spring when they changed the choke plate- took out a hole for better starting on some XT's.

I think he meant the holes in the external plate that turns the throttle.

Sometimes a carburetor is used on different engines and the governor linkage is different and utilized in a different hole. Sometimes a spring might be used in hole due to a different governor set-up. Sometimes manufacturers don't change presses when a design changes and continue to punch out obsolete parts with a new additional hole.

After a short while while I'm using my Craftsman snowblower, the engine starts to miss and eventually dies. I restart it and again after a minute or so the engine dies. This only happens when both the engine and augur are in use. If it's not blowing snow, the engine and augur run smoothly.
I used Sea Foam motor treatment last year when I had this problem and I was able to clear my driveway. But even though I put some in the other day when it snowed, the snowblower again started to die after about a half hour? Can anyone offer a solution? I'm thinking either the fuel filter is dirty or more likely the carb bowl. The snowblower is eight years old.