Yamaha YOB-831L Owner's Manual page 8

Th umb Rest Adjustment and Instrument Maintenance
 Th e joint sections in particular tend to collect
moisture, which can cause cracking. Dry the
joints carefully with gauze.
* Even during playing sessions, remove moisture
from the body interior as frequently as pos-
sible.
 Keep the cleaning swab clean and dry.
 Once or twice a month, wipe the surface of the
instrument using a polishing cloth. Be careful
not to damage the keys or other parts.
 If you feel the keys are not moving well, use a
special key oil (sold separately). Do not apply
too much oil. Completely wipe any excess oil
from the key surfaces.
* Do not apply too much key oil.
* If you are unsure of where to apply the key oil,
consult the store where you purchased it.
8
 Use a tone hole cleaner to remove dirt from in-
side the tone holes and the spaces between and
underneath the keys. Be careful not to damage
the springs or pads.
 Use cleaning paper to remove dirt and moisture
from the pads. In particular, the octave tone
holes tend to collect moisture, which should be
removed as soon as possible.
Octave key
NOTICE
Do not pull out the cleaning paper with the keys
closed. Th e cleaning paper may break and leave
pieces of paper, causing unbalanced adjustment.