Small Engines (Lawn Mowers, etc.): Motor starts & quickly stops, air leak, fuel filter

Question
Small Craftman gas mower.  It starts but then quickly stops if I don't cover air intake. I can keep mower running by covering air intake almost completely so must be air leak somewhere. Has run fine in past.  I noticed that primer ball has cracks in rubber and that it is sucked in when running.

Answer
Hi, sounds like you already no the problem! I think it is your primer bulb! If it has cracks in it & colapses while running then it is sucking air! replace primer blub & check to se if ther is a fuel filter on it? You can get a new primer blub from your local mower repair shop! I think that will solve you problem!!
Let me know what happens!
Curt