After I light the pilot on my GE water heater and turn up the gas the burner kicks on for a couple seconds then produces a rollout flame then goes out. How do I fix this.

You probably need to replace the thermocouple. Get a kit at Home Depot, Lowe,'s or any hardware store for about $10.00. It's easy, but you will have to slide out the burner assembly. While you are at it vacuum out the chamber.

Yes. It appears the flame sensor is probably bad.