Level the range. Make sure the oven racks are installed and the range is positioned where it will be used. Use a level on the racks. Adjust the front leveling legs from the bottom with an adjustable wrench. The back legs can be adjusted from the top and the bottom.
Check the bottom burner flames. Remove the oven bottom and look. Flames should have a blue cone and shouldn't have a yellow tip if the fuel is natural gas. Flames should not lift of the burner ports
Turn the oven off and adjust the GE range's air shutter opening if lifting is observed in Step 2. Reduce the air shutter opening. Remove the drawer and loosen the Philips head on the shutter---the shutter is at the back wall behind the drawer--and rotate the shutter towards the closed position.
Check the top (broil) burner. The air adjustment shutter is in the center of the rear wall of the oven. Again, adjust it if there's lifting.