Honda Pioneer 1000 2017 Owner's Manual page 63

If the doors rattles when closed, turn the door stopper
counterclockwise to adjust the doors. Each door has a double
latching mechanism. Adjust the door stoppers so that it latches on
the second click.
The left and right doors can be adjusted in the same manner.
Adjust
1. Open the door (page 54).
2. Turn the door stopper counterclockwise to extend it, and
clockwise to retract it.
3. Make sure the door is closed securely until the second latch click
is heard.
FRONT
door stopper
REAR
(SXS1000M5P/M5D/M5L only)
door stopper