Flooding can be detected by:

1. leaking fuel from the throttle shaft

2. black colored spark plugs

3. fuel leaking over the top

4. strong gas smell

Causes (not necessarily in order of importance):

• High fuel pump pressure. Especially suspect if recently replaced. Test the pressure and compare with specification in your auto manual.
• High float level. Check and compare with your specifications.
• Leaking float. Heat water to prior to boiling. Immerse the float and look for bubbles.
• Fuel bowl gasket leaking. Check for warped top or bowl. To correct sandwich with blocks of aluminum and heat up.
• Needle & seat gasket not sealing. Inspect carefully for any breaks. Also check to make sure there is not extra residue left on the contact surface of the seat.
• The viton tip on the needle may be damaged. Putting excess pressure on the needle can damage it. Ethanol can also damage the viton tip.
• Dirt may have gotten into the needle & seat. This is not unusual after a new rebuild.
• Ridge worn in the lip of the float causing the needle to bind. This can be smoothed off by using a piece of sandpaper or emery cloth about 1/4" wide. Rest emery cloth over the lip of the float by placing your thumb on top of it, pull the cloth through and that will smooth off the lip of the float.
• Float pin worn or worn float pin holes which allows the float to bobble up and down.
• Float may be binding.
• Cracked casting, passage plugs, or parts not sealing gas tight.