Carby back together and reassembled on the machine. Recoil starter seems to have some issues, so turned the mower over with the drill/socket and noted that the spark looked fine. Threw some petrol in, and after a few rotations it fired up and away she went.

I’m sure the neighbourhood thought we’d set something alight with the amount of smoke from the exhaust, but after a few minutes it settled down to barely noticeable. Maybe had a stint on 2-stroke in a prior life? Anyway, I couldn’t be happier with the way it’s running, after what seems like relatively little input from me.