Does Having A Bigger Penis Mean There'll Be A Larger Amount Of Semen Stored?

Semen is not made or stored in the penis, it's within the scrotum.  And no, that doesn't mean that the bigger the scrotum, the more semen is made.  A man has more output when he's younger, in the years when conceiving children is right, and then less as he ages.

So having a bigger abdomen means you can shoot bigger loads? Awesome. :D