uh oh, i need help

[krazy_texan]

i am getting ready to move in 2 or 3 weeks depends on how long it takes to get the truck driving, anyhoo, my little brother and i go out today to try and start up the truck, did everything i needed to do hooked it up and then tried to start it, now this is the problem, it acted like a cold start or it hasnt been started in a while, sounded somewhat normal and then it backfired and shot about a 4 foot flame out of the top of my carberator, scared the piss out of me as i thougth i screwed something up bad, and i hope that i didnt, but what is causing it to do this and how do i fix it.