[oil pan 4]

I noticed the crapper would flush, fill the bowl, and keep dumping water down into the bowl for a good 20 or so seconds after the bowl had filled.
Lower toilet cycle times would be nice for 2 reasons...
1 it would use less water.
2 it would get rid of those 2 flushers that much faster.

Wanting to fix the problem without spending any money I turned to my smalls plumbing tool box. (a big tool box with the smallest sprinkler and automotive vacuum hose fittings.
I found a vacuum line reducer fitting, stuck that on the end the hose that fills the bowl to try and reduce the volume and increase back pressure to fill the bowl faster. That didn't really work that well, it only knocked a few seconds off over filling time. Then I snipped the bowl filling water line and installed a tee fitting to dump water meant for the bowl into the tank. Both the restrictor and dump tee fitting together made it happen.
That worked perfectly. Now the bowl over fills for less than 5 seconds.

When the bowl was being over filled for 20 to 30 seconds that was nearly a liter of water going down the drain each flush.

In our next house, some how my inlaws cracked a toilet tank.
I insisted on Kohler lower water use toilet or they could install it them selves which involves them paying a plumber to do it.
They got a 1.5 gallon flush Kohler and I installed it for them (really for my self, in the future).