Thank you. I was hoping someone would know an approximate size or even if it’s metric or not. I know a lot of the Japanese motorcycles are all metric. I really don’t use hex or Torx sockets very often. Thx again
One way to get a close (if not exact) size of the hex key in the bolt head is to get a piece of plain paper. Position the paper on the bolt head. Now with the ball end of a small ball peen hammer, gently tap the outline of the hex key depression in the bolt head. This will cut the paper exactly to the size of the hex key.
Now you can take that piece of paper to the hardware store and buy metric and SAE size Allen wrenches to fit the cut out. After determining the correct size Allen wrench or hex bit socket needed, you could return the unused ones.
If you don't have a small ball peen hammer, you can use a flat end pin punch and gently tap the punch with a hammer to cut the outline of the hex key in the bolt head. With a ball peen hammer, it's a one man operation. With a flat end pin punch you need to tape the paper in position or have someone hold in in position while you tap the punch.