Battery Drops Voltage After Kick Back

[mfais]

Hey y'all. First time posting but a long time reader. Here's the issue:

I stripped down and rebuilt a 76 XS650 in the past few weeks. Redid the wiring as well through a simplified wiring diagram that made use Bussmann fuse block. She was starting up good throughout the whole carb tuning and responded well to throttle etc.

Two nights ago I had a kickback which blew out smoke through the carbs. After that happened I had a huge drop in battery voltage and could not start the bike again. The tail light even went out. It took me from a solid 12.8v to the 5-6v range. (Not at the battery, at the fuse block. Battery seemed ok but did drop to 11-12v) I'm using a PS1208-L battery

To help diagnosis: I haven't welded on tabs to mount the reg/rec, fuse block, or the battery itself yet. There is also a lot of extra length of wire that will be removed once those are properly mounted. There is quite a variation in wire gage between the reg/rec, fuse block and battery. The fuse block is just floating around where the battery box used to be. I just checked the cam chain, valve clearance and timing. I'm stumped. What avenue should I go down to figure this out?

ALSO do you have to ground the stator with nylon screws on a 76 xs when you replace the reg and rec with a single solid state unit or is that just for TCI ignitions?

Thanks for the help in advance!

 

[hmusket]

I think your battery is too small, it only has .8 amp hour rating, vs. a 14 amp hour rating for the recommended replacement battery, so its going to lose power quickly, especially since you're providing power to your rotor and tail light, along with your coils. Another thing to check is to see if your advance weights are returning to retard position. Did you clean and lube the advance rod? Are the springs strong enough?

As far as the rec/reg question, we would more info about the rec/reg to give an answer.