This was even more of a problem when I had a Gravely. On it, I often used pins with a ring similar to the ones for key rings to affix to the hole in the end of a pin. You should be able to get these type at TSC. They're a pain to fasten and unfasten.
I even had brush remove the oil dip stick from the Gravely's engine once. Learned to turn the loop inside up against the engine block.
Have had a few of those loop ones come out, as shown above that bend back on themselves. Luckily, no damage done. Have lost 2 holding the bar in on the lower part of the 3 ph on the 4010. One loses one of those spacing collars there, too. Luckily, I bought extra of these but am out again.
Always keep a lookout unless you can get something like the key ring thing.
Ralph