I finally got around to getting the old Victa going again. The problem appears to have been the cut off pins touching. She's running again and I love it.
By the way, I bought one of those alcheapo Victa Vantage mowers from Bunnings a while back, and so far she runs pretty good. I doubt she will last as long as my old Victa but she does a fairly decent job at the moment for a cheap mower.