Help tuning Mikuni BS34 carbs

Hi folks,

Picked up my second bike last week: a 1983 Kawasaki GPz 750.

It was running not great when I got it... popping a lot and not making much power. I pulled the carbs apart yesterday - found them to be pretty dirty - cleaned them, replaced O-rings, and fitted a new fuel filter. Now I'm trying to balance and tune them.

I borrowed a Carbtune from a friend of mine, but don't have a Colortune. I've used the Carbtune to balance them and now could use some advice in setting mixture. The old plugs (I just installed new ones) showed #4 running a lot rich and #2 running a bit rich (after cleaning), so I've leaned those carbs out a bit, but I'd appreciate any other procedures you could provide as to how to set a good idle mixture.

I've heard to tune for maximum vacuum, which I would think I could do with the Carbtune. And also to richen the mixture until the RPM's drop a bit, then turn back a bit from there. Anything else or more specific?

Oh, by the way, I also have an IR thermometer, which is showing the number 1 header to be by far the hottest, number 2 second hottest, and 3 and 4 close to equal. Before I cleaned the carbs, 2 was hottest, 3 was coldest, and 1 and 4 were equal. Could someone comment on whether there's a relationship between mixture and exhaust temperature that I could leverage to help with tuning?

Thanks,
Paul