I recently had all the internal components in my close coupled cistern
replaced. It all works OK, but the flush is pretty lousy - it seems to
move paper around a bit, then give up.

You may find the replacement syphon is designed not to flush the entire
cistern out. This is a water saving measure and required for new
installations that have limited flush capacities.

However, cisterns for old pans designed to have more water may still be used
if the pan is already installed. This is usually achieved by stopping up
some holes in the side of the syphon with the supplied plugs. The holes
break the syphonic effect earlier than would otherwise be the case.

Christian.