Any time you put together a prototype you can expect to run into some issues...
This is a minor issue that will only effect you if you are using the TSR cases with the Panthera E-Start.

- KX GURU RACING TSR BUILT BILLET KX500 ENGINE CASES AND PANTHERA STARTER ISSUES 109.jpg (370.9 KiB) Viewed 11456 times
As you can see there is quite a gap between the cases and the starter housing.
The Panthera starter housing has a lip around the outside edge.
The lip goes most of the way around.
I suspect that it is there for alignment.
The issue is that part of the lip hits on the case.

- KX GURU RACING TSR BUILT BILLET KX500 ENGINE CASES AND PANTHERA STARTER ISSUES 110.jpg (199.9 KiB) Viewed 11456 times
So a little material has to removed from the starter housing lip area.

- KX GURU RACING TSR BUILT BILLET KX500 ENGINE CASES AND PANTHERA STARTER ISSUES 111.jpg (313.03 KiB) Viewed 11456 times
If bikes are for kids I'll never grow up.