The pop at shut off is a trademark of the Savage.  When you turn off the ignition the spinning engine pumps fuel/air into the hot exhaust header where it gets heated up and explodes in the exhaust.

I have not considered this before - but the header has an inner and outer pipe.....perhaps this allows the inner pipe to get much hotter than if it was a single wall pipe.

Allowing the engine to idle a little bit prior to shut down can sometimes help.  A lean mixture tends to make a louder bang, a high idle speed pumps more fuel/air into the header than a proper 1,100-1,200 rpm idle speed.

My bike doesn't do it - some do.  The noise can vary from a gentle "Woof".......to a loud shotgun blast!

Should have mentioned that this is a new battery but I will be pulling it and checking it then putting it on the charger. Then checking my wiring.  I'll check my carb settings it seems high to me as far as idle.

Yea. Today I found my connection from the rectifier with the yellow wires what a loose wire. I replaced the whole connection. New gm weatherpack type. So that connection should be good to go now. Lol.

Well charged the battery fully let it rest as bit then put it in the bike. Only lights working one the bike are the speedo light and my led tail lights. No other lights and no crank. I jumped from battery to starter and it fired right up without hesitation. Time to study wiring diagrams. And I wanted to ride it to work tomorrow. Just got my endorsement put on my license today. It's been a long time waiting for this moment.

Update. After printing a wiring diagram and tracing wires for a couple days. Testing connections as I go. I pulled the tank. Long story short it ended up being the connection for the left side controls which has the clutch switch. Bingo!! We have lift off. When I put the tank on before I must have loosened it and it jiggled apart. Broke a screw on the ignition switch so rn it's hot wired till I can get the rest of the screw removed. But it's alive and I rode it to work. Thanks guys. For the help