Most items that are common have been disscussed.
1> TOS {loose mounting can exagerate the TOS and cause fault, Cracked ears can cause it too}
[you mentioned your guages flickering]
2> Ground {loose or corroded grounds-battery is worst place-}
3> Connectors { @ the guages can get corroded also }
4> Idle setting { set too low, sounds crazy yea but has been culprit to a few }
5> TRE {do you have one, if so unplug it and see if it continues }
6> PCII {uplug it inspect the connectors for corrosion and or condensation }
7> Dirty Fuel Filter & or Inj. SCREENS {clean the fuel filter, run some injector cleaner for atleast 2 full tanks of fuel }
8> and last but not least Kickstand Switch {replace it no fixing it }
Those are a few off the top of my head.
OF course mine is a y2k with over 45,ooo miles.
I have had that sneaky lil die scenario more then once, @ around 20k then again around 35k.
Have tried everything to cure it, listed all of them.
Even installed a NEW battery.
Problem has since gone, unsure WHICH was the fix, but am just glad it stopped.
I have no idea what mods are done to your busa, or the year sorry.
oh one more thing, check you TPS lately?
Jump the dealer plug and see if the TPS is centered, I think that was one fix listed before..
Good Luck,
Ron