What is the clanging sound the motor makes?

I bought a 95 600 shadow. The guy I bought it from used it in burn out pits, he said the carbs need to be rebuilt. I got it to fire up at idle it makes a clanging sound like a fire alarm bell. when i give it gas it dies. If I shoot ether down the front intake it will rev up. Did it drop a valve? what could be the problem(s). I'm thinking about making it into to a bobber depending on how much it costs to get the motor fixed.