Hi
I 've been using Castrol TQF ,170 ml per leg when dry and with 7 inch travel, 72 kg (wringing wet) ,the CZ riders handbook Recommends;
Transmission oil; Castrol SAE 80 ,&Shell Spirax,
I've been using that and now Castrol EP80/90 for all my CZ's gearboxes since 1964!!
and 20 to 1 fuel/oil , have'nt blown one up (yet)
cheers