had a similar issue. first check to ensure a good spark. throw in a new plug to be sure and get the plug grease to ensure a good fit with the boot and no arc’ing. Then if that’s ok, go to the fuel system. Mine started running again after rebuilding both fuel pumps, and replacing the pulse lines. empty these after every race. Also, if someone accidentally used the wrong oil, or a low oil-fuel ratio, it can cause problems. if all else fails, check stator in case it was knocked out of synch. also check all ignition connectors.