Don't know why but suddenly my trunk would not stay closed. After getting home I made a small adjustment to the lock pin (loosen the 1/2" nut, turn pin 3/4 turn counter clockwise, tighten 1/2" nut and voila, it locks again. I have never done anything to the trunk and only have 1300 miles on the bike.

 

As a side note, there is nothing in the supplied tool kit to fit the locknut. I would recommend getting a small wrench set, or a small thin adjustable wrench to keep in the bike.

 

I have the same problem of keeping my trunk lid closed. After reading your post I went and looked at the pin and saw it was wore out where it meets the latch. I bought the trike used and maybe the previous owner was not closing it properly. I am going to try to turn the pin like you suggested to see if that works. Thank you for your suggestion.

 

I gently push the trunk door close and then push the trunk door below the lock until I hear another click.