Fast Idle (cold) rpm jump clutch in/out

motomc1

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I picked up an 02 Busa a couple of days ago. When you cold start it with the fast idle fully engaged it will idle at 2000 rpms. A bit low I know. When you pull the clutch in it jumps to 3300 rpms. When you let the clutch out it drops back to 2000 rpms again. When the fast idle is off the bile stays at a constant 1200 rpms with or without the clutch engaged. I don't think there are any mods that I can see. I synced the TBs today also. What gives? thks
 
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Just the thickness of the cold oil I would guess.

When the fast idle is off it is probably warm so sounds all good IMO.
 
Wow that's a high fast idle. My fast idle is only slightly above 2000 and normal idle is right around 1000rpm.
 
I've had a few Busa's and never experienced this. I have an 06 that doesn't do it either. Other than that "quirk" the bike runs great. A buddy of mine wants to buy it and I don't want there to be an issue with it right off the bat.
 
Both the fast idle and the normal idle can be adjusted via cables right under the gas tank on the right side of the bike.

At full open, the fast idle should be about 3k, and at normal idle people recommend 1250.

Hope this helps, I know it doesn't answer your question, but it will give you some more info.
 
ajblby. You are absolutely correct on idle settings. My little issue is an almost 1000 rpm idle difference with the clutch in and out when fast idle is fully engaged. Actually about 800 rpm difference. I just checked my 06 cold starting and it doesn't do this.
 
When the fast idle is off the bile stays at a constant 1200 rpms with or without the clutch engaged.

Someone said the cold drag from clutch pack to crankshaft has less oil drag. So, you now have a normal idle and she does not move. I'd change nothing. Seems normal if she just purrs at 1200 r's warm.
 
As I recollect, that's how you test your TRE. Pull the clutch in at fast idle and the RPM goes up. That tells you the TRE is functioning properly. I haven't had a TRE in years but as I remember, that's how it worked. My guess is, the bike has a TRE installed. :dunno:
 
Yup, seems you have a G-Pack installed. Even though it's just a resistor (6.8kOhm) it overrides the gear position sensor and pretends the ECU that 5th gear is used so the engine is not restricted anymore.
To check if you have the G-Pack installed just lift the tank and have a look on the inner side of the left side of the frame. You will find a lot of circuits there and one of them has a white connector with three wires. Its shape is three-cornered. Normally the G-Pack ist inserted "between" the original connector...

But, all in all, your idling problem is no prob at all :whistle:

Ciao
D1
 
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