Today after 15 minutes of use, the engine revved for about 20 seconds, it then settled back to normal, however after that, when I engage the auger and try to throw snow, it loses power and barely throws the snow two to three feet. The auger is working. The machine has only been used three times. I noticed that I can not manually change the engine speed even when I move the lever to slow.

Check the linkage between the throttle nad you move and where it connects on top of the carb, does it rotate on the carb freely?

I have to figure out how to take the cover off the carburator. But, when I move the "nad?" the spring pulls and nothing seems to move that it is attached to.

Get us the Sears model number and we'll see what we can find out. Blower numbers may be like 88278 rather than what you see on tractors 512.78869