Basics before resorting to rebuilding

OK, my 1981 KZ750 LTD was purchased on a shoestring budget to be the second "car."

In the two months I've had it, I've totally depleted my professional repair budget on having the detached muffler cross tube spot welded and repairing the damage from a low speed tumble (ignition cover torn off).

The bike sat idle for 3 weeks while I educated myself on DIY master link installation techniques.

Now, it is back in operation but with a very rough idle.

From my research, I'm sure it is probably something with the carbs, but I'd really like to avoid a full disassembly (at least until end of riding season).

What are the first adjustment steps?

Did I understand correctly from previous posts that using higher octane fuel might cause odd idling? That in-tank carb cleaner should be avoided?

Thanks.

del