How can you tell if the doohickey mod has been done on a used bike if the previous owner that was not the original owner does not know? I have a 99 KLR with 8500 miles and an 07 KLR with 2500 miles, and I would like to know if the work has been done without taking things apart to look. Any help would be appreciated. Also, at what point does the lack of this mod become an issue? Thanks!