Question about the "fast idle" lever on the Busa??

[Busa429]

Is the fast idle lever on the Busa's actually a "choke" or does it just raise the idle? A choke would also richen the mixture, so I guess I'm wondering if this does that. sometimes I forget to turn mine off and wonder if it affects mileage.

also...

My Busa is a new '03 and I've just about got it broken in. The idle is very low when warm, and I'd like to know if anyone else has raised the warm idle adjustment on their Busa's. I'm planning on pulling the airbox to remove some of the slack from the throttle cable and thought about adjusting the idle while I'm there.

Thanks

 

[ks-waterbug]

You answered this question yourself when you said "Fast idle Lever"....... Not a choke!

 

[justintime2]

You answered this question yourself when you said "Fast idle Lever"....... Not a choke!

YUP!

 

[CYCLEERIC]

^^^^^ that's right on the $$$ money

 

[IG.]

The idle is very low when warm, and I'd like to know if anyone else has raised the warm idle adjustment on their Busa's.

Yep. Mine was at around 900. Just lift the tank, and see the screw where throttle cables go. That's the one you have to adjust.

 

[EAKbusa]

The idle and fast idle are notorious on the Busa for not holding their settings. You just have to adjust them often and most people adjust them a little higher than the manual suggests. I have my idle set where it varies from 1200-1400 which seems to work fine.

 

[bigpoppa1969]

yup ... notorious,, I adjusted mine two weeks ago, and guess what??? 1100....1200... I gotta tweek her again.... I hate the low rpms... she will be around 13-14, when I get done:angry:

 

[mcoyote]

The 'Busa has an older generation of EFI that does not have an automatic fast idle. For consistency, because one frequently choked cold carb'ed engines, the fast idle lever was labeled the same way as a choke.

You will not hurt mileage or foul your plugs by leaving the fast idle lever going. However, it makes low speed manuevering a bit tricky if your idle is set as high as it should be because it will introduce a surge when you ease out the clutch.

Also, the engine will heat up more in stop-n-go traffic because you'll be idling faster (duh). This is a problem in hellholes like (where I live) DC where one is frequently stuck in traffic like so in hot/humid weather.

The nominal normal idle for a Hayabusa is a personal choice, but averages around 1250rpm. If your idle is in that ballpark and your throttle cables are tight enough, low speed handling and off-idle smoothness is dramatically improved.

There is no need to pull the airbox to tighten the throttle cables, BTW, they can be adjusted at the grip -- just look under it where the cables come out of the shroud and you'll see the adjuster rings.