91mm fork air gap question?

[unfazed]

Easiest way is buy a small syringe (green rubber seal type) put a piece of hose on the end, measure the distance you require from the flats at the upper end of the syringe and cut the hose at the desired length. Fill the fork leg as normal, rest a flat of the syringe on the top of the fork tube and suck out the oil until it stops.