it was installed in 1999 in a new half bath and has not flushed well since installation....we have to hold the handle down until a complete flush occurs and then allow sufficient water to back fill bowl before release too (one of the 1.6 gallon toilets). I have tried different types of flapper valves and chain adjustment with now luck on a solution. How long has yours been doing this? Hopefully some one on the board will have some good suggestions. LJ