my nieghbor put a 500 2 brl on his coronet and couldnt get it to start, i took a look at it, checked a few things and found the carb to have full vaccum at the both ports. if you hooked the vaccum advance up as soon as it fired it would get full advance and shut right off. i plugged the ports and sent him on his way. no vac. advance. anyone ever have this issue?