2001 400ex help

Hi guys,
I have been rebuilding my 400ex and believe I’m close to finishing (hope I’m close to finishing). My problem is getting it to start, if I pull it to jump start it it starts but as soon as I hit the clutch it turns off also if I hit the throttle it bogs down. my question is if this could be a carburetor problem or could it be a bigger issue? When rebuilding it I installed a stage 2 cam and don’t have a muffler on as I am deciding which one to go with