I’ve removed and stripped (didn’t separate or remove slides) the carbs.
There was some detritus in the bowls, and likely in some other, more critical places.

The bike starts first kick and seems to run strong.

The better idle has allowed me to more accurately track down the original issue.
It cuts out when moving the bars -almost certainly a shorting kill switch/ignition wire.

A few questions if anyone cares to assist.

1. The air screws were bottomed out. I’ve set them at 1 1/2 turns out and intend on trying to fine tuning them from here. (Nothing unusual on these bikes I need to know about?)

2. On each carb, on what appears to be a breather (vents to the slide) there has been a short tube, and #150 main jets installed! See pic. Can anyone shed any light on this?

3. The installed jets are MJ 128, PJ 38 are they ballpark? (stock airbox, 2 extra holes, currently no filter*, Tyga chambers.)

4*. No air filter. This is not what I’m comfortable with. I can make one no problem, but haven’t got the support screen (17212-KV3-000) anyone know where I can get one (Or other parts?) The local Honda Shop can not help, at all.
Is the extra (slight) resistance a reason that the filter would be commonly removed. (Track use only) Any insight appreciated.