Kohler Santa Rosa 3323 flush valve

[Greg St]

I am trying to install a new flush valve and gasket in my Santa Rosa toilet. I cannot rotate the vale to lock into place. I have tried using olive oil and silicon grease on the gasket, as suggested to me, but cannot get the valve and gasket to rotate into place. This should be such an easy job except for the difficulty of getting the valve into place. Any help much appreciated.

 

[Peterson]

Maybe running the gasket under hot water to make it more pliable? Or drop the gasket in a saucepan of boiling water for a minute?