The 064a carbs on the K4 use (stock) 105 mains and 40 pilots, air screws set between 7/8 and 1-1/8 turns out from full (gentle) stop inward.
The pods will make it go VERY rich between 1500-3000 RPM, then it will start to lean out suddenly until about 5500 RPM, then go flat lean above that. To reduce this action, I apply (usually black) duct tape over the full outside of the 1 & 4 intake pods, leaving about 1/2 of the inside open. This reduces the effects of rapidly-moving air hitting the sides of the pods, disturbing the donut-shaped 'still-air zone' around the bell area of the carb intake. This upsets the air pressure (thus lowering it) into the emulsifiers, which causes the lean condition at higher (road) speeds. I also tape off the wider area of the 2 inner pods, leaving about 1" exposed at the far end of the pod. This quiets the air a little bit more to improve the linearity of the mixture, which the OEM airbox did well.
Above about 50 MPH, you will struggle with the engine going lean because of all the disturbed air pressures in the carbs, due to the open nature of the pods. So, even if you get the mixture correct in, say, 1st gear at 5500 RPM, it will change as much as 15% at 55 MPH (leaner) because of the pressure changes. Eventually this overheats the engine, causing much piston drag and loss of power, and may also be causing ping, if you can hear it. Suddenly the engine feels like it is losing power (which it is) and after running a little slower, it cools off a little bit and the power temporarily comes back.
Here in the Rockies, I have seen these bikes get trailered home for nothing more than someone having fitted pod filters on them in place of [last trip's] stock airbox: at 8000 feet they stop running altogether, with fouled sparkplugs.
So, maybe start by taping off some of the pod faces and see if that starts removing some of the confusion: I would suggest using the #105 main, #40 pilot, 26mm deep float settings, and 1.0 turns out on the air screws, at the starting point.
