Honda TRX500FM6 Owner's Manual page 169

Air Cleaner Housing Drain Tube
The air cleaner housing drain tube should be serviced in accordance
with the Maintenance Schedule. (Riding through water may require
more frequent inspection.) If deposits can be seen in the drain tube,
the tube must be cleaned before starting the vehicle.
REAR
(1) drain tube
(2) clip
1. Remove the drain tube (1) by removing the clip (2) under the air
cleaner housing (3).
2. Drain the deposits.
3. Reinstall the drain tube, securing it with the clip.
(3) (1)
Air Cleaner
(2)
(3) air cleaner housing
Servicing Your Honda 159