I am about to change the reservoir to toilet gasket and bolts due to a small leak. I've also noticed that the water, once flushed, takes longer than it used to to get from the reservoir to the outlets just below the inside of the rim of the bowl, resulting in weak flushes due to a lower flow rate. Aside from the minor leak, the reservoir is functioning perfectly.
Is there an accepted method to clean the passages in the bowl that carry the water from the reservoir into the bowl just below the inside of the rim such that the water would flow faster? I'm thinking I could address this problem when I remove the reservoir for the gasket and bolts. Thanks.

Back in Wisconsin as a boy over to my father's plumbing shop. Our area has a high mineral content that build up in the toilet bowl. I can tell you how to dissolve the calcium but I strongly suggest that you simply purchase a new bowl.
The only way that I know of dissolving the calcium and mineral buildup is to fill the bowl with muriatic acid and burn it out. I did this outside in the open air but still breathed in the fumes which put a scar on my Linux that I carry to this day.
I strongly advise against using acid. Play it safe and purchase a new bowl. Good luck, Tom

You have a scar on your Linux? Lucky it wasn't your lungs! Fat fingers strike again!!

I definitely wouldn't use acid, like Tom said, however, if you pour some CLR (calcium lime rust remover) down the overflow pipe inside the toilet tank it should help to dissolve some of the build up. Here, pour a 1/2 quart of the CLR into the overflow tube and let everything sit for an hour or so and then flush the toilet...should see plenty of dissolved materials come loose. Repeat this a few times and your toilet should be up and flushing properly in no time...;)

Mark

I've been using a product called " Rydlyme " for the past 25 years. Apex Engineering manufactures this biodegradeable, extremely effective electrolyte. Rydlyme is very safe to handle, and will not harm a septic system, or any piping it comes in contact with; it will, however, discolor or tarnish some metal finishes.
I usually poor one quart of Rydlyme into the toilet bowl, and then use a turkey baster to squirt the fluid into the tank overflow tube, and I will also squirt the rim jets...

Thanks Mike.
I've added that to my Plumbing Data Base. Very helpful. Cheers, Tom