Honda TRX500FE1 Owner's Manual page 188

Brakes
Brakelight Switch Adjustment
Refer to Safety Precautions on page 111.
Rear Brake Only:
Check the operation of the rear brakelight switch (1) at the right side
behind the engine from time to time. Adjustment is done by turning
the adjusting nut (2). Turn the nut in direction (A) if the switch
operates too late and in direction (B) if the switch operates too soon.
RIGHT SIDE
(A)
(B)
(1) (2)
(1) rear brakelight switch (2) adjusting nut
178 Servicing Your Honda