Hello all, I'm back.  More issues I can't figure out, and it's frustrating.

So, to start, I had a post on here a while ago about vacuum leaks.  I found that leak, it was on the vacuum port of the right carb where there was a small amount of corrosion.  So, I actually went ahead and bought a set of clean carbs off a low-mileage wrecked GS500.  I put them on, and voila!  The bike ran.   I *did* also put on new carb boots, just because it was apart and I had a brand new set.

After that, the only issue it had was 7500(ish)RPM and up WOT bogging, and ash-white plugs —running lean.  I identified it as being lean from the aftermarket exhaust.  So, I went up from a 130 main jet, to a 140 main jet.  Still had that bogging, starting either the same or maybe slightly lower at 7000(ish)RPM, with *slightly* more tan (but still pretty white) plugs.  Ugh.  So I put in 150s, and I swear it's gotten worse yet.  And now, one plug is a bit darker and one is pretty damn white.  For reference, my test rides are generally 5-10km, and I got the jets on Amazon (maybe makes a difference, but idk).  This is all a PITA, and I'm sorry for having to come back to the board with questions.

Krazer12

Low mileage could still be clogged if not stored correctly, are the idle mix screws tapered?

Also, check your valves clearances, and sync the carbs(take note of current position)

I'd go back down and go through those carbs too,...  You'll get it but it takes a few times and patience.  Keep messing with them,..