my atlas snowblower model 15 5211A with a 5hp B&S engine will only start if gas is placed in the carb inlet then it only runs for a second.

Ken Watters, February 2007

That is a pretty simple carb. There is a small diaphragm under the rectangular cover on the side. They harden with time and need to be replaced. Another comman problem to look for would be the screen on the bottom of the fuel pick up tube that drops into the fuel tank from the bottom of the carb. They often plug up with dirt or rust.

Rick, February 2007