We have two toilets back to back. One works without any difficulty. The other however has been giving us some problems for awhile. It will flush, but the water doesn't go down all the way sometimes. If you put more water in the seat while it is flushing it goes down every time. I cleaned the underside of the rim with a hanger and removed some built up particles. Adjusted the chain on the handle to take the slack out. Installed new flapper. Made sure the water return was completely open. Plunged as well, but no difference seen. Any further suggestions? Thank you for your time.

After further reading with others problems... I decided to use an old butter knife and clean out what I think is referred to as the "blow hole" and my goodness the mineral build up that came out! So far the toilet if flushing. Thank you.

You have cleaned mineral build up from the jet allowing a normal flush. Congratulations on saving yourself a hefty repair bill. Regards, Tom

Hope it works in the long run. Thanks again.