Two of my toilets, when flushed have a weak flush. The water will fill the bowl but swirl slowly.I've checked the water level in the tank, OK, flapper, OK, vent pipes appear to be clear. Water will flush when I poor a bucket full down toilet so I don't think there is a clog. Any suggestions?

Ugh... (stolen from Speedball1).

Take a mirror, look under the rim. Are the little holes clogged?

Take a wire, coathanger, etc and clean 'em.

You can verify if the are actually working by putting food coloring in the cistern, flush while looking with a mirror and flashlight.

Hope this helps. The mineral buildup will eventually clog thost little holes, affecting the flush.

Ugh... (stolen from Speedball1).

Take a mirror, look under the rim. Are the little holes clogged?

Take a wire, coathanger, etc and clean 'em.

You can verify if the are actually working by putting food coloring in the cistern, flush while looking with a mirror and flashlight.

Hope this helps. The mineral buildup will eventually clog thost little holes, affecting the flush.
I have cleaned the little holes. Sorry, Stew, I forgot to mention that.

Stew you took the words right outa my mouth. The holes on the underside of the rim are probably clogged. The little blue tablet looking things you drop in your tank to "keep it clean" and to make the water a "pretty blue" color is known for clogging these holes.