Gt250 Naked 2005 model carb vacuum issues

Hi. Can someone please assist. I bought a GT 250 naked for my son. There is no fuel pump on the bike and no vacuum lines. I looked at the vacuum diagrams posted before. the bike runs without a fuel pump as I bought it, however it runs out of fuel at 8000rpm. Is this due to the fuel pump or vacuum lines? Doesn’t look like there was a fuel pump on the bike and don’t know whether the 2005 model came with a pump or not.