Honda Power Products TILLER FJ500 Manuel De L'utilisateur page 19

Recommended oil
Use 4-stroke motor oil that meets or exceeds the requirements for API
service category SE or later (or equivalent). Always check the API
service label on the oil container to be sure it includes the letters SE or
later (or equivalent).
CAUTION:
Using nondetergent oil or 2-stroke engine oil will shorten the engine's
service life.
SAE 10W-30 is recommended for general use. Other viscosities shown
in the chart may be used when the average temperature in your area is
within the indicated range.
AMBIENT TEMPERATURE
16