First, I apologize for not answering in your thread, but I get error messages when I try to reply. You’re saying it’ll crank, but won’t fire? Intermittent problems are a pain to find and fix, so I feel for you. I suggest buying a can of starting fluid (ether) and spraying it into the air intake next time this happens. If it does nothing but crank, then your problem lies in the ignition. If it runs on the ether, then dies, then it’s fuel. Hope that helps.