Small Engines (Lawn Mowers, etc.): Gas shooting out of the carburater, electric fuel pump, honda 4518

Question
My Honda 4518 riding mower is shooting gas out of the carb and wont start. It seems to be blowing past the float needle. Iam famliar with the carb, as I have cleaned it and have had it apart before. When the carb is off the engine with the gas line connected, and i turn the key on, the electric pump blows the fuel past the float needle and seat and shoots gas out of the carb. I dont see any thing wrong with the rubber tip and and when I hold the float closed it stops the flow when I blow through the gas intake tube. The electric plunger on the carb works, in and out when I turn the key on and off. Can the electric fuel pump go bad and pump more pressure than it should? and is the needle and seat bad even if it looks good? And there is an O ring on the main jet that seats in  the carb bowl when it is put on the carb, it is shot. is this the culprit? ......Thanks in advance....D

Answer
Needle and seats fail often...I'd start by replacing.  Is the float plastic or brass?  If it is brass, replace the float as well.

Fuel pump problems usually result in low pressure.  I have not seen any over pressure from fuel pumps but it is possible.

Try replacing the needle, seat and float first.

Eric