I cleaned out the gauze filter in the bottom of the petcock, and it was quite blocked, but with a fairly clear gum, which I did not see when it was in place.
A few hours in kerosine and it was like new.
Took the bike for a spin, and problem seems to have gone away. There was a strange knock/clicking noise from the rear end though.
I cut the ride short and came straight home to find one of the bearings has shagged itself.
Might as well do all three if I’m doing one…
Back to Kawasaki again tomorrow then!