We bought a Kohler Cimarron complete solutions 2 pc. toilet about 2 months ago and now it doesn't want to flush properly.The toilet fills half way up with water instead of just wooshing down like it normally does. We've plunged it quite a few times and no one says they put too much paper down it. It just doesn't have that powerful flush anymore.There's suppose to be a long warranty on it. We purchased it at lowe's. Can you help?

Try replacing the rubber flapper inside the tank.

i don't know about your toilet but i googled it and found this it's the flapper and flush valve
https://www.plumbingsupply.com/images/kohler-flush-valve-1044458.jpg
and you can go here and see all the parts in it,hope this helps you out.
https://www.plumbingsupply.com/kohlertoiletparts-cimarron.html

The exact cause of a Kohler Cimarron toilet running non-stop depends on the exact model of toilet owned. In some, the lift chain connected to the handle can become kinked, preventing the ball seal from covering the drain completely. Just unkink the chain to fix this. In other cases, the float ball is stuck against the side of the tank, preventing it from returning to its normal horizontal position. When this happens, the toilet's tank doesn't stop filling with water. The excess continuously flows into the overflow pipe. Dislodge the float ball from the side of the toilet and this should clear the problem. Likewise, you might consider shortening the armature on which the float ball sits, so it won't become stuck again.

Read more: Troubleshooting a Kohler Cimarron Toilet ' eHow.com http://www.ehow.com/how-does_5017443_troubleshooting-kohler-cimarron-toilet.html#ixzz1CxKmz9ZQ

Hi, if you remove the cistern lid and flush the toilet, look at the float (back left) to see if this is rising freely when the water fills back up. Once the water has stopped filling, check the fill level lines on the large syphon in the middle of cistern. Your model of toilet has an eco flush which will be lowest line to save water, so not as much water will flush out. There is a long plastic screw on the float (back left) which you can turn to adjust the water level to the higher line on syphon (1.6 gallon flush) and turn it slowley till the water level reaches that mark. flush a couple of times to see it is filling back up to the set amount.

check fill tube from the fill valve to the flush valve, if the end of the hose is close to the watr level it will back syphon.... recommend also putting in better inner components.. fluild master 400 a fill valve and a nice red korky flapper

Is the fill line in the tank loose? Does it just shoot water into the tank itself? I had this issue until I realized the while fill tube is supposed to be pushed into the black cylinder/small plastic tube in the middle of the stopper assembly. After i pushed the line into the tube, the bowl would always only fill a little bit. Now it fills almost a 3rd of the way up the bowl and doesn't bubble during flushes.

Check the float in your tank and watch it and make sure it is not hitting the sides of the tank to not allow it to fill up.

You might want to check the flush cylinder, to see if it has water in it. It has to be water free, that way the air in it, lets it go down easier, during fill up.

is the syphon lifting every time?