Yamaha DT501988 Owner's Manual page 35

NOTE:~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pre-operation checks should be made each time the motorcycle is used. Such an inspection
can be throughly accomplished in a very short time; and the added safety it assures is
more than worth the time involved.
LL,
WARNING:
If any item in the Pre-Operation Check is not working properly, have it inspected
and repaired before operating the motorcycle.
5-2