78 KZ1000 LTD Issues

Okay folks - I put a new gas cap on the tank and a new fuel valve/petcock. Replaced the filters and did carb rebuild kits. I also lubricated the engine advance.

I got the beast started after a few tries and I'm getting white smoke and popping backfire. I didn't take it on the road but rode it around the block.

I'm guessing there is some kind of adjustment I need to make on the carbs? This is probably a no-brainer for some but I've never done any of this before. What do I do next?