Hey slide,
its happen twice on one motor,
when i first brought the bike i rode it around the padock all seemed fine with the gears.
i gave it a oil change and found a gear dog in the sump.
So i did a full gear box and top end rebuild and six years later found the broken peice in the sump again broken again :'(
I picked up a spare motor from a wreckers for parts when i first got the bike , for parts not just for gears etc.
and last weekend checked the gears in that one
and that one is broken as well, its the same gear broken as the fist motor.
I have two DR500s but the second bike hasnt been pulled apart to check that one , i raced it a few weeks back it runs fine ...
so one motor has broken two .
and a spare motor i got from a wreckers was broken as well not broken from me.
and the second bike i havent checked yet..
So thats three broken all up, but i have only broken one ..ITs the size of the dogs on forth gear they are smaller than the rest and break