Hard to say, no flicker from the oil light. I usually set the idle closer to the specified 1000rpm, just sayin' that with a proper vacuum sync that mine will idle smoothly down to 800rpm. Many people cannot get theirs to idle smoothly below 1200-1500rpm.
I don't spend much time at idle either! 😁
1-1/2 turns out on the idle screws is fine. Trying to set the idle mixture screws using the 50 or 100rpm drop method can be maddening since these don't always idle smoothly. Synchronizing the carbs using a set of vacuum gauges on the other hand will go a long way towards smoothing out the idle...
Cool 8-)
Carbs look simple enough, but if they are not set up nor assembled properly they are absolutely the demon spawn of satan. I've gotten pretty good at carbs, but I do not like working on them.
I use this method (scroll down):
http://www.lowridersbysummers.com/parts/index.htm
Of course, I purchased bushings in different lengths and spent less than $10. I like this method since stock appearance is maintained, stock springs are used, and the amount of preload is equal to the length of...
People seem to value the earlier models (69-76) more highly than the later models (77-78) which works for me since I value my K8's quite highly:
Plus, I'm having an absolute blast with them! I would steer clear of the "A" (automatic) models since they are sort of freaks of mechanical nature...
The older SOHC/4 Hondas (69-78) typically get a lot of attention wherever I go. Everybody either had one or knew someone that had one (dad, brother, best friend, etc). Been to Bike Week at Daytona many times and my Harley riding buddies get so pi$$ed when people fawn all over my 78' CB750...
What motivated you to put huge 125 mains and then step up to massive 130 mains? Stock mains were 115's. Have you checked your plugs? I'll bet you find them black from carbon being overly rich. Check your compression while you're at it and let us know what you find.
Hard to say, you are making too many changes at once to be able to pin down a single cause. The air fuel screw has the most impact at lower rpm and I don't think it would have much effect at higher rpm. As for syncing the carbs, these motors run very well with a proper carb sync, but I would...
2 and 3 can indeed be timed separately with the Dyna S.
https://www.mpsracing.com/instructions/Dynatek/DS1-1_1-2.pdf
You can swap the coils from 1/4 and 2/3 by switching the blue/yellow and the spark plug leads to see if the problem follows the coil. If not, then you can focus on the 2/3 trigger.