This is the fuel pump you need and with some basic tools and skills it can be replaced in about 30 minutes or less;
https://www.amazon.com/Airtex-E11015-Electric-Fuel-Generator/dp/B0076D5OI2
If that's the case then the fuel pump needs to be replaced. When we had a 5500 it would only run 10-15 minutes in temperatures over 90F until we replaced the pump.