Just installed the Champion, no leaks yet, it does have the newer flush valve..Is there anyway to adjust for a longer duration flush so that it empties more of the tank?..Just doing test flushes at this point.,The flush is very brief..I'd like to see a longer duration of rushing water to be sure to clean the bowl..will I just have to live with the 1.6 gpf function ?..I read on a post that if you make the chain longer it will flush the whole tank..haven't tried it..but I'm not sure that would make any difference...I flush and hold the lever down and it doesn't seem to make a difference in the amount of water used...any adjustments possible ?...Thanks..Don