I have a 1983 XJ750 Maxim. I bought it from a guy that said it has been sitting for a couple of years. Well the throttle cable seemed to be stuck so I replaced that and then cleaned the carbs, changed the oil, spark plugs. It runs, but it won´t stay running. Any suggestions to what could be the problem? We have also flushed the gas tank. Any suggestion would be greatly appreciated. I´m all out of suggestions.