Without knowing all of your mods it's hard to know for sure but I can tell you that your main jet is way too big. If it has a factory exhaust odds are most everything else is stock which would put your main in the 120 - 145 range depending on airbox and other stuff.
Your no bottom end problem doesn't have anything to do with the main size. It sounds like your pilot is too lean and your air/fuel needs adjusted, get that part running right and pipe will stop glowing and you'll have more bottom end.
06 OCP TRX500ER