I wouldn't try let the starter run for 30 seconds. As others have said, I prime it once, try to start it. I let it go 10 seconds or so. If no start, prime it again. Rarely does it not start after the second priming.
When we first bought our Motorhome, we took a trip about a month after we bought it. The generator fired right up while we were driving. My wife tried to heat something in the microwave and the generator cut out after about 30 seconds later. Couldn't get it to start. It turned out to be a bad fuel pump in the generator. It was replaced under warranty. I don't think the generator had 5 hours on it when the fuel pump failed.
I don't remember off the top of my head, but the manual should tell you how to read an error code which might point you in the right direction. If I am not mistaken, we got error 34. If memory serves correctly, I believe the fix for error 34 was to have it serviced by a technician.
-Michael