Predator Generator Won't stay running

Working on Predator 6500/5500W generator with 420cc engine. It will start and run at a slow rpm for about 5 seconds and dies. I replaced the carb after trying the two that camber with it. Replaced fuel cutoff valve and all fuel lines. Checked and adjusted the valves. Nothing changes. It supports and dies. I tried putting fuel in carb with not effect. There are no air leaks behind carb. Confirmed proper gaskets. Governor linkage and springs are properly installed. Low oil shutdown is not there problem. The anti backfire solenoid is installed and I tried a solenoid where I cut the plunger of sand it has the same problem. It's seems like it has a little of blowback out of the carb. Any suggestions? It is a model 63083.