Another question.....Choke on FI?

[OB_boneman]

Here's another question I've been pondering
for some time and one many couldn't answer with a reasonable amount of sense....

Why on earth does the busa have a choke
if it's fuel injected? The triumphs I've
seen don't have one and cars certainly don't have them....is this a poor mans version
of FI? What's the scoop?

[OB_Dr Busa]

It's not a choke, it's an idle adjuster. I'm surprised that they didn't make it adapt itself.

But on the other hand it works well as a cruisecontrol. When the engine is hot i can do 90 km/h not touching the throttle !!! You can do this since the "choke" doesn't change the fuel mixture.

http://home.swipnet.se/fredrik_sagvold

[OB_Bob]

Its not a choke. Just a sort of fast idle. It opens the throttle blades.
But, it sort of has a choke in that the idle is richer with a cold motor than hot. The ECM compensates for engine temp, among other things.
Bob

[OB_boneman]

"Idle adjuster", interesting....with a little
more work that could have been automated.

So does the cable actually link up somehow
to the adjuster knob that resides on the lower right portion of the bike? Or does
that adjust something separately from the throttle bodies?

Anyway, thanks for the tip....I'll have
to give the cruise control idea a go.

[Gixx1300R]

I would rather keep the fast idle manual.I can just imagine an Automatic idle getting stuck.It happens with cars all of the time.

[OB_EXCLR8]

If they automated the choke they would have to install some type of stepping motor and controler. That would have added weight and cost. If they used an idle air then it would have to have one for every cylinder, again more weight. They could have used an O2 sensor and just richend up the mixture a bit, but then you could not use leaded fuel witht the stock FI. I am sure there is some other way to do it automated, but most would add weight and cost. I am glad they did not.

EXCLR8

[This message has been edited by EXCLR8 (edited 03 February 2000).]

[OB_Animal]

Right, could have been automated, but that indeed adds parts/weight/cost and means that you don't CONTROL it to your liking anymore!

Honda uses an automated version on their EFI but this can mean that it's still "adjusting" when you would have thought it no longer needing it and also still influencing mpg in a bad way.

It really is just a fast-idle and I've completely removed the entire thing on mine as I don't let the bike idle at all before jumping on it fully geared-up. I start it up when I'm all ready, do a very short bit of fast idle with my own right-hand (well developed that one I might add ...) and then ride off to slowly warm it up without heavily loading it.

If you wanna see how it works you only have to look on the RH side under the tank where
the throttle cables lead to.


[This message has been edited by Animal (edited 04 February 2000).]