Yamaha TTR90(M) Owner's Service Manual page 8

4. When transporting
another vehicle, be sure is kept upright
and that the fuel cock is turned to the
"OFF". If it should lean over, gasoline
may leak out of the carburetor or fuel
tank.
5. Never start your engine or let it run for
any length of time in a closed area. The
exhaust fumes are poisonous and may
cause loss of consciousness and death
within a short time. Always operate your
machine in an area with adequate venti-
lation.
6. Always wear a helmet, gloves, boots,
trousers, and jacket for motocross riding.
the machine in