E150 Motor losing prime

I have aN Evinrude ficht engine that keeps losing prime.Motor will run for a couple hours then quit. The fuel line bulb is flat. I pump it back up after a good 15 pumps then it runs again for a couple hours. Seems to be happening more often now. Had it to the dealer and he replaced the fuel filter and fuel line bulb, but no fix. IM sure someone has seen this problem before and any suggestions would be very much appreiciated. My thoughts are a bad fuel pump? or a clogged fuel tank pick up?
Thanks , Markus
2005 150hp V6 2 STROKE
model# E150F5LSTF
SN 05030367

Would start with a pressure test at 3-5lbs of the fuel lift pump, more than likely you have a bad diaphram in the pump. If you do not have a manual, would recommend getting one, these motors are fairly complicated. The experts will post with any other recommendations. I am just a BBC junky! http://www.bassboatcentral.com/boardstuff2/beers.gif

I do have the manual and am a pretty good wrench on bikes and snowmobiles.I will cruise the weekend with a auxillary tank to exclude the fuel line and tank pick up. If she still pukes , I will pull the pump. IM leaning towards the pump because it takes 15-20 bulb pumps to get the bulb hard again. Wish I could handle 20 hard pumps, snicker! http://www.bassboatcentral.com/smileys/Laugh.gif
Thanks for your help and I will respond with my fix for other forum users.
Have a great safe weekend.
Markus