how to fix a twyfords poor flushing toilet?

i replaced the syphon and the syphonic aspiration with a turbo 88 and a syvac syphonic aspiration,still cant get working by that i mean the toilet paper doesn t go away because of a very poor flush,i read somewherelse that it might be the washer not fitted firmly which it can be as i m going to dismantle again or either i need the original twywords parts,anyone knows,thank you for reading. i hope to hear from anyone who s done this before....