+1 I hear fuel pump only when first turning on key to start my bike...Only time I hear the fuel pump is when I turn on the key, and then only for a few moments.
Could the sound be from your fan maybe not cutting off?
Could you start by telling us the model of bike you have?My 2006 kawasaki fuel pump I just took out is a 4940-0015. Can I use the 4940-0022 ON my bike?