Hayabusa idle speed, and running rich

[corrcullen]

Have a pair of Art cans on my 2002 Hayabusa, they are just slip ons, but over the last few weeks while on my european trip, the bike seemed to be running rich, and back fired just a couple of times.
There are no other mods apart from a TRE fitted, and a scottoiler.
Would the art cans change the running of the bike as I dont have a power commander fitted?
Also the idle speed keeps adjusting itself, usually to a lower RPM.
I have reset it, and used thread lock on the threads of the adjustment screw, but that didnt seem to work, I dont think the screw itself is moving.
Could the art cans also cause this, or could there be something else wrong?

[WARputer]

What are you seeing that makes you think it is running rich ? How often do you have to adjust the idle screw ? How many miles are on the bike ?


I could see the slip ons causing some deceleration "popping" but as for running rich & idle adjustment, those are probably unrelated problems.

[JAYPEAbusa11]

Can you smell unburnt gas at all? You most likely need to remap your fuel delivery, then add the TRE again.

[montañes]

I add my question to this post cause it's about idle.
In my K7 when I bought idle was at 1.200 rpm (+ -) like you see at this video (http://www.arca.imperator.tk/idle.wmv) (still don't drived it)

Now after the first repair intervale think that my mechanic adjust very low idle (or may be idle down itself...)
Idle was at a cold start at 950-1.000 rpm growing up to 1.100 rpm when busa was hot (with the usual fluctuation)
I have read in forum that last 1st gen. Busas are low idle from factory and it's better for oil pressure for example that idle stays high.
Now I adjust idle at this way (sorry I still don't have any video but I can make it, if is neccesary):
-when bike star cold idle is 1.050 rpm
-when bike is hot idle is 1.200 rpm (green needle)
all with normal oscillation but don't exceeds 1.250 rpm

http://usuarios.lycos.es/fotofiles/reloj.jpg

Owner's manual says:
"...so that engine may run at 1.050-1.250 r/min"

Do you think I have a correct idle speed?
:thumbs up:

[Tybalt]

1100 rpms is my idle.

[V8Pinto]

Very common Busa trait. The idle screw loosens over time and the idle gradually drops. When it's running about 1,000 or lower you will experience infrequent stalling. Just turn the idle up to 1,200 and you're good.

The early Busas (1999/2000 maybe?) had a remote idle adjust screw that peeks out of the fairing near your oil fill cap. You can get the parts from bikebandit, dealer, various Busa guys to add this to your bike or you can just adjust the idle to 1,200 every once in a while.

On the popping - I think all the Busas pop, you just can't hear it with the stock exhaust. Mine is tuned pretty well and it pops. I wouldn't worry about it. It's normal.

[montañes]

Very common Busa trait. The idle screw loosens over time and the idle gradually drops. When it's running about 1,000 or lower you will experience infrequent stalling. Just turn the idle up to 1,200 and you're good.

OK, thanks now is at 1.200 r/min warm.


The early Busas (1999/2000 maybe?) had a remote idle adjust screw that peeks out of the fairing near your oil fill cap.

Yes, latest busas screw is under fuel tank at the right side (near throtle pulley)

Well, if in a future my busa experience frequently idle drops, I will see what make with the screw...

[Tybalt]

OK, thanks now is at 1.200 r/min warm.


Yes, latest busas screw is under fuel tank at the right side (near throtle pulley)

Well, if in a future my busa experience frequently idle drops, I will see what make with the screw...

your TPS(throttle position sensor) can effect your idle as well C- in the middle , this is set from the factory but vibration can offset it and need to recalabrate it.

[Quasar]

your TPS(throttle position sensor) can effect your idle as well C- in the middle , this is set from the factory but vibration can offset it and need to recalabrate it.

While the TPS does affect all aspects of engine RPM, vibration won't alter the TPS unless it was not tightened properly from the factory. Typically, they are torqued as required and usually are thread-locked as well in an effort to avoid such issues.

The Hayabusa has one of the most erratic idles of all the sportbikes especially when a comparison is made of a cold verses a fully warmed engine. Suzuki did a piss-poor job in this area. On the other hand, with the 99's thru 07's lacking any ability to open the throttle butterfly via ECM control, idle control remains quite limited. All the fuel in the world could be added to a cold engine, but if you can't open the throttle butterfly to provide the necessary matching air intake, you cannot effectively control the engine's idle RPM. If 2008 Hayabusas possess a mechanized throttle butterfly, then they shouldn't have the same erratic idle issues as the earlier Hayabusa (and maybe they don't, but I don't have a 2008 Hayabusa nor do I know anyone who owns a 2008).

The Hayabusa idle should NOT be adjusted while the engine is still cool or cold. The engine should be running for at least 15 minutes and the idle should be set to 1,250 RPM. This RPM yields the absolute best idle characteristics and even makes cool engine operation acceptible during engine warm up (though I still advise use of the fast idle lever until the engine has had a chance to warm up).

[montañes]

While the TPS does affect all aspects of engine RPM, vibration won't alter the TPS unless it was not tightened properly from the factory. Typically, they are torqued as required and usually are thread-locked as well in an effort to avoid such issues.

The Hayabusa has one of the most erratic idles of all the sportbikes especially when a comparison is made of a cold verses a fully warmed engine. Suzuki did a piss-poor job in this area. On the other hand, with the 99's thru 07's lacking any ability to open the throttle butterfly via ECM control, idle control remains quite limited. All the fuel in the world could be added to a cold engine, but if you can't open the throttle butterfly to provide the necessary matching air intake, you cannot effectively control the engine's idle RPM. If 2008 Hayabusas possess a mechanized throttle butterfly, then they shouldn't have the same erratic idle issues as the earlier Hayabusa (and maybe they don't, but I don't have a 2008 Hayabusa nor do I know anyone who owns a 2008).

The Hayabusa idle should NOT be adjusted while the engine is still cool or cold. The engine should be running for at least 15 minutes and the idle should be set to 1,250 RPM. This RPM yields the absolute best idle characteristics and even makes cool engine operation acceptible during engine warm up (though I still advise use of the fast idle lever until the engine has had a chance to warm up).

Weel quasar, I think the same for example with the Busa idle, is really a poor work. Allways I say that don't understand why suzuki's engeneers thought to do it thus. May be a high performance bike needs like a F1 or another vehicles to stay high rev. before fly? I don't know but another brands use a different system more similar to convencional cars idle.
We say that it's a little coarse... :(
If a don't give a small touch of gas or keep clucth press about 2 or 3 seconds, when start cold sometimes engine stop; then I return to start and running fine.

The 2ºnd GEN busas have a special idle control like you said.

Tomorrow I will give a ride; in my state during day temperature is arround 95º F (35º C) then I will record a idle video (I think it's the best way to see it)

[Quasar]

Here's the procedure I follow every time I start my 99 Hayabusa when its engine is cool or cold:

1. I pull the fast idle lever to a point that I know will yield roughly between a 1,500 to 2,500 engine RPM even with a cold engine, then begin cranking the engine.

2. Once the engine starts, I decrease the fast idle lever until the engine RPM is holding at 1,500 RPM. As the engine warms, the RPM will typically begin to increase, so I continue to decrease the fast idle lever to maintain 1,500 RPM.

3. Once I get riding along at a steady speed by just a few minutes later, I simply return the fast idle lever to its lowest position. This works very well.

I have my idle adjusted to 1,250 RPM as per my engine when operating at its normal temperature.

Remember, on the earlier Hayabusas (99’s thru 07’s), YOU are the automated choke/warm-up system! (sad, though true :oh yeah:)

[montañes]

Ja, ja.... :oh yeah: I'm tired to use the 'automated choke system' at my carburated bikes...

Well here is the video (http://www.arca.imperator.tk/idle.wmv)of my busa cold and warm idle. Seems that from the last time I used it has lowered.

Comments please ;)

[montañes]

Today I re-tuned my idle.
Finally have it at 1.200 r/min aprox. cause if I put it on 1.250 sometimes rise untill 1.500
Video here (http://www.arca.imperator.tk/idle2.wmv)
Thanks specially to Quasar, now sounds a little better :oh yeah:

[Quasar]

Today I re-tuned my idle.
Finally have it at 1.200 r/min aprox. cause if I put it on 1.250 sometimes rise untill 1.500
Video here (http://www.arca.imperator.tk/idle2.wmv)
Thanks specially to Quasar, now sounds a little better :oh yeah:

Even if it would occassionally rise to 1,500 RPM at idle, that certainly beats having an idle that drops and wants to stall out. :oh yeah:

[matthewwatton]

Hi, I have an 02 Busa which used to do the same. I agree with all the other posts about Busa's being prone to uneven idling but I found the original TRE was the cause for my problem. I have just fitted a Smart TRE, loads available on ebay for about £25. The unit recognises when the bike is in neutral and turns off, the standard TRE doesn't and whatever the technical reasons are (someone will know) tells the bike it is in 5th gear. If you pull in the clutch while the idle is high you should see a drop of about 500 RPM. I cured the back popping by removing the PAIR valve or the cheap 5 minute trick is to put a marble in the PAIR feed from the airbox, the one on the brake lever side just above the throttle linkage. Hope this helps, cheers, Matt.

[Tybalt]

Hi, I have an 02 Busa which used to do the same. I agree with all the other posts about Busa's being prone to uneven idling but I found the original TRE was the cause for my problem. I have just fitted a Smart TRE, loads available on ebay for about £25. The unit recognises when the bike is in neutral and turns off, the standard TRE doesn't and whatever the technical reasons are (someone will know) tells the bike it is in 5th gear. If you pull in the clutch while the idle is high you should see a drop of about 500 RPM. I cured the back popping by removing the PAIR valve or the cheap 5 minute trick is to put a marble in the PAIR feed from the airbox, the one on the brake lever side just above the throttle linkage. Hope this helps, cheers, Matt.

:cheers: welcome