Helix 150 fuel valve
 

So i recently acquired a helix go kart in pretty good condition. I noticed i wasnt getting gas so i checked all the lines and they were ok but i found out gas wasnt going through the fuel valve thing on the bottom of the gas tank. there is a little rubber piece in there and when i push down on it fuel goes through. Is this piece supposed to be there? Please help

If you haven't already, check the vacuum line from the intake, and make sure it is opening the fuel valve diaphragm. Other than that, you can likely replace the vacuum petcock with a standard shut off valve and cap the vacuum port. As always, be sure to flush the tank and install an inline filter, and go as big as you safely can with the fuel line diameter.