Generac IX2000 Generator, Fuel Problem?

I have a Generac IX2000 that is 5 years old. The generator will run for about 5-10 minutes fine after I prime the system and start it. Then it will start to heave and cut out then dies. If I hit the primer ball after this it is just air. If The unit is running and this starts to happen I can hit the primer Ball 5-6 times and it will start running normal again. But after 5-10 minutes same thing.
 
I was going to try and just replace the Diaphragm fuel pump figuring the Diaphragms are wore out. But Generac has discontinued the Pump. The sad thing is that they just discontinued the IX line from what I can tell but a lot of people are still selling new units.
 
Part Number is 0H43470184.
 
I am not sure what to do. I am also not sure if I am on the right track either. But I can say that the thin diaphragms they are using in the pump won't last if I do get it working. The Vacuum side is just a circle but has a beaded edge that fits into a groove on both pump pieces. The gas side is similar it has a round bead around the edge and also a a bead going down the middle that is not a straight line it is straight then a half circle curve and back to straight again and each piece of the pump has a grove that the beads fit in so I am not sure if I could just make them myself. 
 
Any thoughts? Could I use a different pump for a real small engine and just fix a mount? What would be my options?
 
Am I missing something else here and it is not the pump?
 
 
Thank You
 
 I added a picture with the Gas side showing. You can see the line with the hump in it going down the middle that is a groove of which the Diaphragm has a corresponding bead on each side to fit that groove.