Glad you got it sorted out mate. Had a 172 Cup for 5 & half years, then a full fat 172 for nearly 2 years, got a 182 Trophy now.
Did have an issue with 172 Cup where drove home from work, parked up it was fine. Then went out to it the next morning and it wouldnt start, just kept turning over and wouldnt fire at all.
That day I hopped in the raider and took that to work and later my mate towed the Cup to his work and said that the TDC sensor had gone. They put a new one on and it was spot on again.
Was the oil in the Cup quite black/dirty? wouldnt really use flushing oil in F4R, just cheap 5W-40 and drop it after a couple of hundred mines if it was me.