Toilet won't stop running.

68MHJCs

First of all the toilet is only about 4 years old. When I flush it the water rises to the top and keeps running as water fills into the run off area. The black plastic float (i guess its called) will rise to certain point but not all the way up to turn off toilet and stop water from continuing to run. As soon as I lift up on the black plastic circular float and pull it up a 1/2 or less the toilet shuts off. How do I correct this problem? It does seem to have some sort of adjustment thin metal rod (size of bicycle spoke) connecting to the top of the black plastic float that may or may not be the adjustment system for the tank shut off.

68MHJCs

I believe it is a Kohler model if not mistaken.

Termite

If you pull up on the black float that is attached to the rod, the tank should shut off. If it doesn't, you need to replace the entire flush valve assembly. It isn't very hard to do. Just shut off the water, drain the tank, unscrew the old one and put in the new one.

Before replacing, you might adjust the float down the metal rod so the float gets buoyancy sooner. It might be out of adjustment. There should be a little clip that attaches the float to the rod.

68MHJCs

How do you change this?? To make it shut off sooner? Is it a screw or what?

Termite

There are dozens of configurations out there, so I can't say without seeing it. But, the float is normally adjustable on the metal rod. It usually involves a little friction clip that you pinch, and the float can slide to a different position on the rod. If your float isn't secured to the rod, there's a good chance that the rod isn't being pulled upward by the float, and that's stopping the fill valve from shutting off.

Pull up on the float while the toilet is filling and let me know what happens.

Then pull up on the metal rod when the toilet is filling and let me know what happens.

If neither of those things stop it, you might take a picture of the tank's inner workings and post it here.