I timed it, and this old-and-busted toilet takes three minutes and fifteen seconds from flush to refill. This isn't even one of those newfangled low flow toilets, neither. This thing's at least 22 years old. The water valve is open all the way, so that shouldn't be a problem. Will replacing most of the internal parts help? Right now, I have a Fluidmaster 400A (not sure how old it is), and I bought a replacement kit (which included everything except the overflow tube) from Fluidmaster that is either the same stuff or the latest version. I know it wouldn't hurt to have new parts back there anyway, but I'd like to know that I might actually see results before I begin the process. I'm reading web pages stating that the refill ought to take around 30 seconds, which is mind-blowing compared to what I've been living with. Oh, one last thing: water pressure is low right now, what with people watering their lawns, lack of rain, etc. I know all that, but it's been a slow filler for a long time, regardless of season.