Honda NRX1800 2004 Owner's Manual page 107

Engine Oil & Filter
JASO T 903 standard
The JASO T 903 standard is an index to
choose engine oils for 4-stroke motorcycle
engines.
There are two classes: MA and MB.
Oil conforming to the standard has the
following classification on the oil
container.
(1)
(2)
(1) code number of the sales company
of the oil
(2) oil classification
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Servicing Your Honda