There are a few options for swapping out the Honda XR650R radiator cap. You can swap the KX500 radiator cap onto the XR650R, or you can buy the SRC Racing XR650R Radiator cap, or you can but the cap produced by Stant Manufacturing in California.

I have read great reviews of the Stant caps, they seem to be built very well. However, I am not positive of the pressure rating of their cap for the XR650R. I have read it is 1.6 Bar, but I have also read it is 1.8 Bar. If anyone knows for sure please send me the info or comment on this post.