Toilet Bowl Water Level Alternates Level and Flush

[leichte]

My toilet bowl is starting to alternate water levels of about an inch below and an inch over normal bowl levels. When the level is low the toilet doesn't flush all the way. When it's high is does. I've adjusted flapper chain but still not working. This has been driving me crazy. Should I just replace all the guts in my tank?

Any thoughts?

Thanks!

[Mr_David]

Look at the refill tube coming from the fill valve into the over flow.
When you flush it there should be adequet flow to refill your bowl to the proper level. If not enough flow the wtr level is to low. the next flush uses the stored tank water to refill the bowl before the siphon action of the flush starts but the not enough water to complete the task.

How a toilet works

[majakdragon]

There is no way to control the water level in the bowl, unless there is not enough water in the tank when flushing. There should be a small tube going from the fill valve and into the overflow pipe. This assists in getting the proper refill. Otherwise, the level is controlled by the trap in the bowl.It can only fill a certain amount, and then the trap overflows and the water goes into the drain pipe.