Good day and welcome to Just Answer. My name is XXXXX XXXXX I'd be happy to help you with your problem today. You need a valve adjustment
the motor does not need to come out for that
you just need to check your clearances & get the shims you need
with the shims do I have to use a feeler gauge to work out what size shim I need or is there next size up to replace all.
no, you need to going with the feeler gauges & measure the clearances that you have, note them & then note the shims sizes that are in, you then use than info to determine what shims you need.
The factory service manual has a shim chart in it & you can likely find that on a ZZR rider forum
I just don;t have one here
Thanks Braian will go with that and get back to you. cheers.