Dear list !

Could you guys please watch those short youtube video to help me
diagnose my van problem .
I have an air cool engine 2.0L 1983.

Symptom: basically the engine start , but stall after a few second.
I have so many things to check out but I would be very glad if anyone by
luck can diagnose and pin point the problem just by listening those video.

Tip ! The engine was rebuilt and was working fine a week ago before I
did some electrical modifications to add a secondary battery !
I don't think I I messed up anything but who knows !.

https://youtu.be/VQ_Auha-rV8
https://youtu.be/Ax4g5CNPCJU

Thanks so much

Chris