KZ 440 engine starts on left cylinder

Just got my 1984 KZ 440 ltd running. It starts on the left cylinder and after a bit of warm-up the right cylinder runs, but misses--any thoughts?

Just because it's needs to be ruled out but how are the valves? Have they been adjusted to spec? If they have then I would be looking at the carb, Vacume leaks around the boot to the engine all on the side that is missing. If the boots are original, that would be a red flag.

Thanks for the input. This is a bike that hasn't been running for months and I don't know much about the bike's history as I just bought it. I noticed that the plugs were on the black and sooty side when I pulled them out. I'll take a look at the engine boot, adjust the valves and go from there. Thanks.

also check the resistance of the plug wire.