Can't adjust flush time for complete flush, low bowl water level

Yes,there it is!You can adjust your water level at the flush valve..You can see the ball there you need to adjust that so that the water level of your tank goes to your desired level.

Check the water level in the tank and also make sure the flapper is staying in the up position long enough for a complete flush.

If I understand correctly, your water level inside the bowl is 3 or 4 inches from the top of toilet seat?
Sounds peculiar to have that water level since you would get splashing etc.
That is not sanitary, and would be a code violation.
Look at side profile of tank.
Look at porcelain behind bowl and you can see outline of "s trap."
This is the internal trap that each toilet has built in.
Purpose of trap is to a) set water level inside bowl and b) just like a sink trap, seal pipe from sewer air from entering home.
Photo shows trap on sample toilet, with line showing approximate level of water inside bowl.
Since photo is at an angle, the line appears to go downward instead of level. Again the line is approximation, and photo intended to show where you can look on your toilet.
Your tank should have similar s-trap feature. From the feature on your tank, you can see what level water is intended to be inside bowl.
Some more expensive tanks, outline of s-trap is not apparent.

If the water level is so high that you experience unsanitary conditions, this is a code violation, and toilet should be replaced.

Quick web search turned up Kohler contact page: http://www.us.kohler.com/general/contact.jsp
KOHLER Customer Care at
Phone: 1-800-4KOHLER (1-800-456-4537)
Hours: 8:00 AM - 5:00 PM (Central Time) Monday to Friday
You can refer Kohler to this link on Fixya so they can clearly understand issue.

please make sure the water is off!
the fluid master has a slip ring at the bottom of the float base it pulls up then you can adjust the float up or, down and, snap it back down.
at the top of the float you will see a cross-headed plastic bolt; this is adjusted for fine level control using a large conventional philips screwdriver.

As long as this toilet is NOT a pressure assist toilet. Then it probably has a water saver flapper that you can replace with a non water saver flapper. This will allow it to flush more. Be advised you may have to adjust the water level after the change to prevent it from double flushing. Hope this helps.

check water level in tank if low adjust float to proper level inside tank will see a level line also check flap as to opening all the way may have to adjust chain if problem continues hard water can cause build up in water holes and narrow tank to bowl tube

Hi
try to increase the amount of water for each flush .

These models need to have a flush valve flapper that has a styrofoam float on the lift chaninof the flapper. Go to hardware store or home improvement store and get a 'Korky brand toilet tank flapper with float 'ball". Cut the rubber ring piece away from the flapper and you don't need it (see cut here marks on flapper). Install flapper and adjust the float fairly close to the flapper.
When the water level drops in the tank and reaches the level of the float on the opne flapper, the flapper quickly closes causing the toilet to have a "surge" of siphon action which forces the water in the bowl to be drawn out.

It sound like you have debris caught in the fill valve. Remove the top where the washer is and put your hand over it and slowly turn the water on to flush the fill valve. Replace the washer with a new one and then replace the top.

If you have the old ball and **** style, replaceing the diaphram is harder so I would recommend replacing it with a fluidmaster fill valve. Hope this helps.

2 possibilities.

1) The diaphragm in the Sloan is for a urinal. (1.0gal vs. 1.6gal);

2) Not enough water. (stop partially closed, supply undersized)