First of all, on a carbureted engine you have a "carburetor". This is an air constant / fuel is the variable type induction.
On a fuel injected engine you have the inverse rather and here the air is the variable, and fuel is the constant. So to speak.
On a carbureted engine you "choke" off, or restrict the airflow so as to enrichen the mixture. That is, when the engine's cold, you want a richer atmosphere in the combustion chamber to smooth out the warm up cycle. As the engine increases in temperature, the "choke", or restriction of the airflow lessens to a degree as things expand, cyclinder rings warm and seal more efficiently, and air flows smoother when warm, and the engine finally reaches warm "running" temperature.
On the Hayabusa, the fuel injection is "mapped" or predesigned for early startup as the coolant temp sensor, among others, tells it it's simply "not warmed up". This causes a lower idle (not a low idle) at startup, and increases as the very same things start to happen, i.e. cylinder rings start to warm and seal, head intake ports warm, and the airbox does much the same.
The only thing the fast-idle, not choke, lever does is adds more air, increases idle speed, and can actually leans the the enrichened mixture ever so slightly at start up which when "very cold" (let's say 0 degrees C, or 32 degrees F) makes for a harder start as the air is very dense and you may not get the engine hitting on all four until you add a bit of air to the mix, allowing a better "rough" mixture of fuel and air at startup. When "very cold" you have a very separated air / fuel vapor mix going on than when the two are at warm running temps where the fuel "atomizes" smoother with the air flowing by the "injector head".
I believe the owner's manual states, run the fast idle lever for only a few minutes at startup so as to inspire the engine to warm quicker (and not run an overly lean condition as it warms), the oil pressure increases, and the cam chain doesn't slap the guides quite as aggressively.
I've noticed when cold at around 1,000 rpm's the chain slaps with the cam gear rotation (could also be any combination of straight-cut gear driven goodies) as the engine is warming (surging), whereas now, I have the idle set at 1200, and I get a reasonably smooth (No knocka-knocka) warmup cycle. I run the fast idle lever up around 1500 to 2000 rpm's for a period of no more than two minutes. Out here, it doesn't take long for the engine to start warming itself up except in the Winter.
I'm also one of those Busa owners that "always" pre-warms the motor before "rolling out". Some of my buds are fire-it-up and let's go types, me I like knowing she's at least "near" running temps before I go running out an onramp at WOT, which I happen to do a lot of.
I have noticed on later model Gixxers, they incorporate a warmup cycle in the injection / ignition mapping to accomodate for the lack of a manual fast-idle lever. "Nice". Get's the oil flowing, warms the cylinders, and by the time they're taking off, the engine's almost completely warmed up. I think Zuke was just milking a good thing with our older-style injection / ignition modules, that's all. Just my .02...........
Self-cancelling what
................is that like a "what's a TRE question" ?.
