Right....Having a nightmare here. I’m not being daft in saying there should be a thrust washer and wave washer on the idler gear shaft of a 2016 Blade? Took the clutch cover off yesterday and for the life of me do not remember seeing either. Now panicking because I can’t find them to put back on !
https://www.fowlersparts.co.uk/parts/5828554/cbr1000rr-fireblade/starting-clutch this wavy washer thing? Have a look at the clutch cover sometime the oil film stuck one washer against the clutch cover and as removing the wavy get drops below to pan; strong mag pick up or remove sump to get it out. And check the work area they can just drop out etc. I would check the diagram and make sure you have the right part at the right place