Honda CTX200 Owner's Manual page 36

Use unleaded petrol with a research octane
number of 91 or higher.
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.
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