Honda CBF600S 2006 Owner's Manual page 46

For E,F,EK,ED, IIIED,VED,VF,VIE,VIIEK,
VIIIED:
Use unleaded or low-lead petrol with a
research octane number of 91 or higher. We
recommend that you use unleaded petrol
because it produces fewer engine and spark
plug deposits and extends the life of exhaust
system components.
Use unleaded petrol with a research octane
number of 91 or higher.
The use of leaded petrol will cause premature
damage to the catalytic converter.
32
NOTICE
If "spark knock," or "pinking" occurs at a
steady engine speed under normal load,
change brands of petrol. If spark knock or
pinking persists, consult your Honda dealer.
Failure to do so is considered misuse, and
damage caused by misuse is not covered by
Honda's Limited Warranty.