This one plugs the hole that one of the shift forks rotates in on the magneto side.   I knocked mine out with a punch for no justifiable reason.

Would I use some form of adhesive when reinstalling it?  It is listed in the CT3 parts list diagram in the section titled "Shift Cam Form" as ref  no. 21, part number 214-15385-00-00.  The service manual doesn't address it.

Thanks

Might go back in tight as is but to be sure can you slightly expand it somehow. Tap something tight fitting inside it. But then you have to get it of the tool without damage. I'm guessing it's rubber coated. Some epoxy type glue should hold it. That's my guess.

, merci!