+4 with the others. I always run until I HAVE to switch to reserve. It sputters and recovers very quickly - just a couple of seconds - barely slows me down.
Must be either a clog somewhere OR is there a lot of vacuum pressure in the tank when it's low? The stock cap is not vented. I've been using the flush mount vented cap almost since I got the bike. In general, my fuel flow is not quite as good when low - I can just about tell I'm going to hit reserve. Vacuum in the tank could also restrict gravity flow like holding your finger on a straw.
