how do i know if cord or mechinism is broken?

If the cord is broken you would be stood there with the pull cord handle in your hand with a portion of cord hanging from it. If the recoil isn't taking the cord back for storage, the return spring is probably broken. If the pull cord works ok but isn't engaging with the engine it needs surgery, either way there is more wrong with it than you could cope with or you wouldn't be asking. Sorry, time to get your wallet out.

Tinker
March 2009