The stock XR650R chain has no master-link.
It is a "staked link" or endless chain.
Honda advises this type of chain do to the high tourqe output.
Minor surface rust should be no problem, usually a bit of gear oil on a rag will eliminate it.
Or simply lube it with a commercial chain lube deemed safe for "o-ring" type chains.
Your friendly neighborhood Honda dealer should be familiar with the "uncorcking" process on the 650R.
And no, it's not really very complcated.
Basically you:
1- remove 2 plastic resrictors from the airbox.
2- replace the stock rubber intake manifold with the optional "power-up" Honda part.
3- replace the stock muffler insert -w- the "power-up" unit.
4- rejet the carb. 68s pilot jet, needle -w- clip in 3rd position, and anywhere from a 170 to a 180 main jet depending on your altitude.
(im running a 170 in mine. NewMexico "high desert")
For more info check this out.
http://xr650r.us/xr650r_faq/
Uncork that lil bugger and enjoy! :yeehaw:
Have fun and ride safe! :thumb: