Oh, it's so much fun being a pain in the butt. Here's my story, and here's why you should be very careful before you assume a record is open - just because there's none listed in the rulebook for your chosen class.
Nancy and I did just that one time a few years ago. We ran her bike, qualified (pretty easy to do on an open record), and made the return run. The numbers were good enough to be justifiably happy with them. We went to impound and were ready to open the engine for measuring -- when someone brought out a list of all records. Dang -- there WAS a record in that class -- but for whatever reason it wasn't listed in the rulebook. Whether someone forgot to send that particular record to the printer, or whether the printer left it out for whatever reason -- we learned that a racer might do well to confirm absolutely that a class is open, or, if not, what the record really is in the chosen class.
Pain in the butt story over for now.