Choke & Fast Idle

[ambaig11@yahoo.com]

Hey guys, just looking for some advice/help. I am a newbie with bikes so bare with me. My busa has been starting up pretty ruff lately. Most of the time I have to rev the engine initially for 30 secs. to make sure it won't stall right away. I have no idea what the purpose of the fast idle switch is, all I know is that the lever is all the way down and if I bring the lever up I can't start the bike. A friend told me that the lever is suppose to be all the way up when riding the bike (only down when warming up the busa) and that I need to readjust the idle, is this true? when do you use the fast idle? Is the fast idle the same thing as a choke? any advice?

Sorry for the many questions, I REALLY LOVE THIS BIKE AND WANT TO KNOW EVERYTHING ABOUT IT!!!!!

P.S. The bike is in the Caribbeans, a little below sea level, will this impact my idle?

 

[FL Knifemaker]

Hey guys, just looking for some advice/help. I am a newbie with bikes so bare with me. My busa has been starting up pretty ruff lately. Most of the time I have to rev the engine initially for 30 secs. to make sure it won't stall right away. I have no idea what the purpose of the fast idle switch is, all I know is that the lever is all the way down and if I bring the lever up I can't start the bike. A friend told me that the lever is suppose to be all the way up when riding the bike (only down when warming up the busa) and that I need to readjust the idle, is this true? when do you use the fast idle? Is the fast idle the same thing as a choke? any advice?

Sorry for the many questions, I REALLY LOVE THIS BIKE AND WANT TO KNOW EVERYTHING ABOUT IT!!!!!

P.S. The bike is in the Caribbeans, a little below sea level, will this impact my idle?

From what I understand, the fast idle does nothing any different than holding the throttle open a little. It's just that, a fast idle for warming the bike up, hands free. It doesn't act as a choke at all. I'm at about 10 feet above sea level and mine has run fine since new, no problems, knock on wood!!

 

[tbonebusa]

raise the warm idle speed to 11-1200 rpms.....the fast idle lever should bump it to about 1500-1600 when fully deployed. Idle speed adjustment is a knob under the tank...you can get at it without lifting the tank if you are really nimble.

 

[VaBusa]

My bike needed the idle adjusted (actually needs it again)...you shouldn't have to run the bike with the choke on; may foul your plugs, right guys?

At any rate, the idle adjustment is on the throttle side of the bike, under the tank. Mine's an '03 and the idle can be adjusted by pulling the fairing aside a bit, but I don't know that that's true for all years. I've heard it's not.

Let me see if I can find a pic someone just posted up recently showing where the idle control is...just takes a screwdriver to adjust it...

 

[VaBusa]

Better yet, link to someone that posted up about this earlier this week...

Bump it up and see if that helps...

 

[Projekt]

Look at your owner's manual. There you will find the details necessary to adjust the fast idle and to what RPM to set it. The fast idle control is located in the position traditionally used for a choke control thus earning it the misnomer of being called the choke on the Hayabusa. Chokes are only ever used on carburetors. Since our bikes are injected, chokes are not used. Chokes are used on carbureted motors to aid combustion in a cold climate and cold motor. They work by increasing the effect of vacuum on the primary (fuel) jets (which requires an extensive lecture in the physics and dynamics of air movement). This effect results in an enriched intake charge by drawing more fuel into the airstream which in turn changes the air-fuel ratio from a standard average 14:1 to 11:1. This is what allows the engine to run in cold conditions because the increased amount of fuel burns easier than the leaner standard mixture. Once the engine warms to a temperature that allows it to support combustion at 14:1 a/f ratio it is important to open the choke because the added fuel will begin to deposit excessive unburned carbon onto the combustion chamber surfaces to include the spark plugs. These deposits if allowed to accumulate on the spark plug's electrodes will increase spark-gap resistance. Therefore diminishing and preventing effective ignition of the air charge resulting in reduced performance and fuel economy.

 

[BA BUSA]

My bike needed the idle adjusted (actually needs it again)...you shouldn't have to run the bike with the choke on; may foul your plugs, right guys?  

At any rate, the idle adjustment is on the throttle side of the bike, under the tank.  Mine's an '03 and the idle can be adjusted by pulling the fairing aside a bit, but I don't know that that's true for all years.  I've heard it's not.

Let me see if I can find a pic someone just posted up recently showing where the idle control is...just takes a screwdriver to adjust it...

M it's only a fast idle to help warm up the bike....the Busa has no choke

 

[MoosesBusa]

FYI... It is my understanding that manual Chokes are for Carburated Engines. Busa's are fuel injected. There are exceptions to every rule but the Busa is not one of them

 

[DAB]

When you raise the tank to get access to the idle adjustment screw, try moving the "choke" lever back and forth and you'll be able to see what it does. It moves a "cam" that pushes against the throttle "lever" which is moved by the cables of the handlebar twistgrip. All it does is crack it open slightly to raise the rpm so the engine doesn't stall while warning up. You'd get the same affect if you held the throttle open a fraction manually.

 

[#cruncherbusa]

Hey guys, just looking for some advice/help. I am a newbie with bikes so bare with me. My busa has been starting up pretty ruff lately. Most of the time I have to rev the engine initially for 30 secs. to make sure it won't stall right away. I have no idea what the purpose of the fast idle switch is, all I know is that the lever is all the way down and if I bring the lever up I can't start the bike. A friend told me that the lever is suppose to be all the way up when riding the bike (only down when warming up the busa) and that I need to readjust the idle, is this true? when do you use the fast idle? Is the fast idle the same thing as a choke? any advice?

Sorry for the many questions, I REALLY LOVE THIS BIKE AND WANT TO KNOW EVERYTHING ABOUT IT!!!!!

P.S. The bike is in the Caribbeans, a little below sea level, will this impact my idle?

this is just sad!

 

[05BUSABLU]

you also have minor adjustments on the bars where the cables come in. but after the 500 mark i just went through and check/adjusted what i need to. take the front seat off(2 bolts on either side)then the 2 bolts by the triple tree where the tank mounts. then there is a little bar in the trunk to keep the tank raised while you work on stuff. you can run the bike and adjust while this is all apart as well.

 

[shenoyp]

Welcome to the board

...From what i get to understand!! The idle on your bike low... I sugget you set it between 1050 - 1250 RPM. It's pretty easy... just pop your fuel tank up, and you will see it on the right side of the bike if your facing the road!!

Hope that helps

 

[ambaig11@yahoo.com]

Hey #cruncherbusa, bro if your not gonna help, fine. I just don't need any sly remarks though. I was under the impression that this was a forum to learn. I am a newbie, I admit it, but I am TRYING to learn.

 

[DAB]

Hey #cruncherbusa, bro if your not gonna help, fine. I just don't need any sly remarks though. I was under the impression that this was a forum to learn. I am a newbie, I admit it, but I am TRYING to learn.

Unfortunately, if you've been on this board a while you get to hear the same questions again and again, and it can get a little tedious.

I'd advise you to spend time reading the many useful posts on this board that cover this subject (and lots of others) before you post questions that have been addressed numerous times.

Use the search feature (at the top of the forum page) and also just scroll through the old listings under categories like New Owner and Maintenance etc.

I lurked on this board for quite a while before I started posting, and I learnt so much about the 'Busa that I haven't had to ask many questions.

Welcome to the obsession.

 

[VaBusa]

M it's only a fast idle to help warm up the bike....the Busa has no choke  

Well, I call it the choke...does the same stinkin' thing!

You boys are soooo technical...

 

[stkr00]

M it's only a fast idle to help warm up the bike....the Busa has no choke

Well, I call it the choke...does the same stinkin' thing!

You boys are soooo technical...

Actually Michelle...they do exactly the opposite of each other

CHOKE:

A "choke" takes the throttle plates (butterflies) and closes them down to a predetermined setting. This causes the intake path to be blocked off/restricted. When the starter is energized, the rotation of the engine causes a stong vacuum to be drawn within the intake manifold. In a carbuerated engine, this cause more fuel to be drawn through the idle circuit needle valves and thus richens the air/fuel mixture. This allows for more fuel to be ingested than normal, and when the air is cold and dense outside, it provides enough fuel to support combustion.


FAST IDLE

A fast idle is merely a cable that is connected to the throttle shaft with a manual slide adjuster mounter on the left handlebar. When this slide adjuster is rotated, it pulls the cable, which rotates the throttle shaft until the tab contacts the fast idle adjustment stop screw. This actually OPENS the throttle plate a small amount which allows more air to enter the engine. Now for the big difference...

As the throttle shaft rotates open, the throttle position sensor sends a signal to the ECM/ECU which tell it that the throttle is being applied. This now looks for a value on a data table (Fuel Map) to balance the injector firing rate, ignition timing, and the air flow. The air flow signal is sent from the MAP sensor (Manifold Absolute Pressure). The ECM/ECU adjusts each one of these variables until they are all balanced and within tolerance of the Fuel Map.


See...they are NOT the same

Hope this helps someone understand the difference, and why the terminology is important.

Not pickin on ya M...just figured it needed some clarification, and you gave me the opportunity.

 

[VaBusa]

M it's only a fast idle to help warm up the bike....the Busa has no choke  

Well, I call it the choke...does the same stinkin' thing!  

You boys are soooo technical...

Actually Michelle...they do exactly the opposite of each other

CHOKE:

A "choke" takes the throttle plates (butterflies) and closes them down to a predetermined setting.  This causes the intake path to be blocked off/restricted.  When the starter is energized, the rotation of the engine causes a stong vacuum to be drawn within the intake manifold.  In a carbuerated engine, this cause more fuel to be drawn through the idle circuit needle valves and thus richens the air/fuel mixture.  This allows for more fuel to be ingested than normal, and when the air is cold and dense outside, it provides enough fuel to support combustion.


FAST IDLE

A fast idle is merely a cable that is connected to the throttle shaft with a manual slide adjuster mounter on the left handlebar.  When this slide adjuster is rotated, it pulls the cable, which rotates the throttle shaft until the tab contacts the fast idle adjustment stop screw.  This actually OPENS the throttle plate a small amount which allows more air to enter the engine.  Now for the big difference...

As the throttle shaft rotates open, the throttle position sensor sends a signal to the ECM/ECU which tell it that the throttle is being applied.  This now looks for a value on a data table (Fuel Map) to balance the injector firing rate, ignition timing, and the air flow.  The air flow signal is sent from the MAP sensor (Manifold Absolute Pressure).  The ECM/ECU adjusts each one of these variables until they are all balanced and within tolerance of the Fuel Map.


See...they are NOT the same

 Hope this helps someone understand the difference, and why the terminology is important.

Not pickin on ya M...just figured it needed some clarification, and you gave me the opportunity.

Well, I'm blaming the hubby for calling it a choke then...

See, I'm all screwed up!

Damn it Jim...stop trying to teach me!!! LOL

 

[stkr00]

M it's only a fast idle to help warm up the bike....the Busa has no choke

Well, I call it the choke...does the same stinkin' thing!

You boys are soooo technical...

Actually Michelle...they do exactly the opposite of each other

CHOKE:

A "choke" takes the throttle plates (butterflies) and closes them down to a predetermined setting. This causes the intake path to be blocked off/restricted. When the starter is energized, the rotation of the engine causes a stong vacuum to be drawn within the intake manifold. In a carbuerated engine, this cause more fuel to be drawn through the idle circuit needle valves and thus richens the air/fuel mixture. This allows for more fuel to be ingested than normal, and when the air is cold and dense outside, it provides enough fuel to support combustion.


FAST IDLE

A fast idle is merely a cable that is connected to the throttle shaft with a manual slide adjuster mounter on the left handlebar. When this slide adjuster is rotated, it pulls the cable, which rotates the throttle shaft until the tab contacts the fast idle adjustment stop screw. This actually OPENS the throttle plate a small amount which allows more air to enter the engine. Now for the big difference...

As the throttle shaft rotates open, the throttle position sensor sends a signal to the ECM/ECU which tell it that the throttle is being applied. This now looks for a value on a data table (Fuel Map) to balance the injector firing rate, ignition timing, and the air flow. The air flow signal is sent from the MAP sensor (Manifold Absolute Pressure). The ECM/ECU adjusts each one of these variables until they are all balanced and within tolerance of the Fuel Map.


See...they are NOT the same

Hope this helps someone understand the difference, and why the terminology is important.

Not pickin on ya M...just figured it needed some clarification, and you gave me the opportunity.

Well, I'm blaming the hubby for calling it a choke then...

See, I'm all screwed up!

Damn it Jim...stop trying to teach me!!! LOL

I was wondering when you'd get back to this one.

Couldn't resist

Make sure the Hubby reads it then, if it's his fault.

Hi Mr.VaBusa