Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Never realised they have a special thread.
[...] it would be better engineering practice to have no threads there as you indicate but with the bush clamped against the shock forks it shouldn't matter much [...]
[...] Never had a 500 kickstart slip,[...]
As above, with shaft worn it's difficult to get a good solution. Something that's possible to help (this is quite common in moto-X bikes with kickstart used alot) using a black (engineering) allen/socket bolt, plus a washer under the head and grease on the bolt threads. It can let you tighten the kickstart the most possible to clamp it with the teeth available. They are the strongest bolt and not plated, so will rust and need to be covered in grease after installation. If that bolt can't clamp it, then it's absolutely a new shaft as this will take more torque than any other generally available bolt.Otherwise known as a high tensile bolt ( or cap head socket set screw!) 😉 (Attachment Link) This type of bolt.