Engine idling high with light switch

Whats up guys? Well i tried searching around but honestly, i am not quite sure what to search for. I have a 82 CSR 650. So here is the problem. When the bike is idling, I flip the headlight switch, and the revs jump up. When i first did it, it actually jumped up close to the red line and starting backfiring like a mofo. I currently have to start the bike with the battery charger/starter we have at work. Before i can switch the charger off when the bike starts, the engine revs are also high. As soon as i turn the charger off, the revs go back down to normal. What might cause this? I tried searching but i honestly dont know what i am searching for. Thanks in advance. Oh and if it makes any difference, although i dont see why, this is the first time i got it started. The carbs were completely gummed up and i finally got them clean. Started the bike up and this is what happened.

-Kyle

Here is a video of the problem
Bike reving up

Id start with checking regulator/charging system

Thanks a lot man. I ordered a new battery from Z1 so hopefully it gets here soon so i dont have to keep cranking the bike off the battery charger. I am scared i might have fried something while attempting to get the bike started. hopefully not though. Thanks again for the quick response.

I hope you haven't cooked the electrics on your bike, but for future reference do not use a battery charger to start your bike. You can start your bike by jumping it from a car battery with the car engine NOT running. Ed

The video sounds like you are running on two cylinders at idle. When it revs up it sounds like the other two cylinders start firing.

Either there is a wiring problem, or there is a voltage-related problem that is affecting the two non-firing cylinders.

Thanks guys. I will check all of that. I feel really dumb for not using a car battery. I work in a freakin garage for christ sake. well hopefully the damage isnt to bad. Once i get the new battery I will let you guys know the deal with the regulator/charging systems and what not.