I Have A Briggs & Stratton 4.5 Hp Lawn Mower. It Starts Then Stops After 2 Secs. Can You Help?

Ours is doing the same we needed to change the plug and the filter we got bad gas one time so we had to drain the fuel tank. If nothing seems to fix it call where ever you got it from and tell them it has a warrenty they need to replace it ,there might be a factory defect who knows.

Clean or fix the carburetor

Try pressing the primer right after you start it until it runs

If it's new they should be able to look up the records and service it under the warranty and even give you duplicates of the paperwork....