Relatively speaking, those were always slow to fill. One advantage was that baths at that time were plumbed with 1/2 pipe, the pressure from a well could be marginal and if the toilet flushed while someone was taking a shower, the pressure drop on the Cold could result in the Hot flow being too much. Plus some of the old ones held more than 5 gallons of water. My 1.6 gallon Totos will fill before I can get my hands washed.
Be sure the supply stop is fully opened.
Hey, 15 minutes fill sure beats going to the outhouse when it is below freezing. I have experience with that .

Here is a link that might be useful: Song

I'll bet mine would take several gallons, if not 5! I'm tempted to switch to a more modern toilet, but I wonder whether my 4" sewer (house to main sewer)line is too large to move it effectively.

I remember pulling that trick on people- wait 'til they're in the shower and then flush the john ... yep.

If I clean up orifices on the toilet is there a reasonable chance that it would flush efficiently with a reduced fill? Well, I'll try that anyway, so maybe I'll just find out myself.

Thanks for your help. Not the first time.

M

Most likely, the refill valve is not opening properly. You can replace the valve assembly or, if it's a Fluidmaster brand, you can replace the seal which is located under the cap at the top of the unit.

Thanks! Replaced old unit with a Fluidmaster ($7.XX at big box store) and refill now takes two-three minutes. Really didn't realize at first how much the old one had slowed down. Took maybe half an hour to do the repair, and most of that was getting the old one out.

Thanks again.

Mark