DynoJet rejetting and slide drilling

I have a 2nd gen 88 RC24 that I'm building into a dedicated track/race bike.
I have removed the carbs to give them a good clean. Ultrasonic and carb cleaner, clean as a whistle. The bike came with a K&N filter and a Laser 2into1 muffler. I have changed the airbox for a de-snorkled airbox for increased flow.
It came with a DynoJet kit. I have installed 128mains (I believe stock is 118?), DynoJet needles at the recommended #3 out of 6 position with one washer, left the stock 38 primary jets and have the airscrew at 2 turns out, all recommended by DynoJet.
If I go WOT from 2500 it stumbles a little. It's good from 3-4.5.
4.5 to 6.5 misfires very badly. If I modulate the throttle at this point, I can smooth it out a little, but not great. I believe this is the level where the slide is lifting.
6.5 to 10 seems ok but not a lot of power when compared to my two other stock RC24's.
Over 10 falls flat. Struggled to get to rev limiter.

I have a feeling it's still too lean on the main. That's pretty easy to fix and will dyno test it in the near future. However my concern is the big stumble at 4.5-6.5. I believe the slides have been drilled using the provided Dynojet drill bit as it fits tightly in all slide holes. Not a huge fan of irreversible mods like this. It feels like the slides are opening too much at that rev range. By modulating the throttle it closes it slightly. Is this normal for slide drilling and throttle modulation is required, much like a direct attached carb (ie CR carb etc)?
Or is this not how they're meant to behave and something is wrong?
Could it be running too lean/rich? Or both wrong AFR and slide opening?
I've been doing some digging on VFRD and VFRW forums, and general consensus seems to be the DynoJet kits are very poor.

Interested to find out what experienced people's recommendations are for my setup.

cheers

 

Yes the DynoJet kits are so so. Depending on your motor build you may not want to go by DynoJet's recommendations. The larger hole in the slide lets it raise faster. With the larger jets and raised needles it sounds like it's to rich. Drop your needles one groove at a time and test. You can always fill the slide holes with epoxy/JB Weld and drill smaller holes.

Most carb adjustments like that are trial and error. May take a few times and adjustments to get right. Each motor no matter what is different. So Dynos recommendations are general, very general. When tuning carbs you can go as far as altering the emulsion tube holes to adjust fueling at specific rpm band range (very small)

Now if you have a engine or chassis dyno it will be a lot easier and faster to tune.