Can anybody offer suggestions on how to "Tweak" the flush settings on a
Shires Close Coupled WC.
It is a split button type (Short/Long Flush) with a bottom fill.
I had the misfortune to remove the Flush Button in order to facilitate the
droping of a Blue Block of some kind and the "Simple" refitting of the Flush
Button turned out to be anything but !!
Eventually I had to Lower the adjustable frame which straddles the flush
valve but this has resulted in a somewhat insipid flush...
?

I'll have a go, these are the type I have some experience with:

Can you see a small plastic block like thing, on the valve body? if so
then this is the small float and is used for adjusting the small flush,
its normally white and it clips to a plastic arm. You should be able to
slide the float up and down the plastic arm adjusting the flush. The
small float should be 2cm below water level.

If your water level is too low you need to adjust that with the grey
bolt on the inlet valve

Think yourself lucky you haven't just completely totalled your toilet
pan which I just did trying to install the thing cutting my hand in the
process. The pan looked like there had been a shark attack in it
according to the mrs, oh what a night...........

HTH

Cheers

Richard