This is my first KX500 so I don´t know much about it.
This is how it looks like, when the horizontal axle is fully out and the valves is placed on the marks.
They look pretty close
The top picture looks almost spot on
The bottom one looks like it opening a little too much/ This could down to not having the side guide bush not inserted fully{tighten philips screw}
You need to get both valves lined up with exhaust subport with rod fully out /like top picture/ with side guide bush fully inserted {one with philips screw]
With that done you kipps timing is Spot on
DONT TRY SETUP TIMING ON CLOSED POSITION
You the can fix the over closing issue, usually needs about 5mm added on to the allen key stop bolt {flwheel side}
As soon as the exhaust sub port closes is where u want to be on close position {rod in }
its is possible to modify the kipps rod with a internally stopper {i use a little nut} and ignore the timing marks
its is also possible to modify ONE OF the valves /make the kipps chamber work better /BUT I WOULD NOT WORRY ABOUT DOING THAT UNLESS U HAVE A BIG UNDERSTANDING OF HOW IT ALL WORKS
heres a pic anyway /arrow point to the nut stopper on kipps rod