Ok, I posted another thread about an erratic idle on my 04, i initially found the TB’s to be way way out of sync, i finally got to ride the bike yesterday to test ride it & found the bike wants to idle anywhere from 1500-1700rpm, the idle adjustment will not lower the rpm, infact i backed it all the way out and made no difference. I then did the jumper sequence and found the TPS to be good. sooo i checked for vacuum line leaks & could not find anything, While spraying around the bottom of the TB’s with brake cleaner i could get the rpm’s to come down, I then removed the TB’s and noticed the clamps that secure the intake boots to the cyl head were completely tightened all the way & i could fairly easily rotate the intake boots, imo they were lose and could be my issue, do you folks think i’m on the right track? other then the “hanging” idle the bike runs very good, no surging, runs smooth once rolling but the idle is a’miss!
2004 busa idles fast/hanging idle
- Thread starter cottbusa
- Start date
busakiller
Registered
Sounds like you might have a vacuum leak around the throttle bodies? Try sealing them up. See if that helps at all. Your going about it the right way.
The rubber can rubber boots between the throttle body and intake can crack or split. Did you make sure they are fully seated onto the throttle bodies and the intake sometimes the inner two are hard to see if they're not seated properly
Thank you guys for the suggestions, everything has checked out good except the TB to cylinder head boots not being as tight as i think they should be & there mounting clamps being as tight as they can go. Also i do not have a shop manual for one of these, can anyone provide me with a schematic of how all the vacuum lines get routed & where they plug in to.
.....might be of help too.
Rubb.
Rubb.
Thank you Rubb! It is of help, the previous owner had this bike apart & i wanted to be sure where everything went, i’m sure he was chasing the same problem as i am now, he was thinking TB plate issue on the #2 cyl & trying to “tune” it with the sync screws. It was idling, chugging, & almost had a miss in it before sync was done, it sounds good as soon as i get the clutch out & rolling but it just wont idle down.
Mine moves freely, so much so that it snaps back like the throttle does, is that right? I thought they stayed in place until the operator/rider slides it off just like a normal choke leever.
If it were me I would lift the tank and watch the action as I manipulated the switch and adjust the screw as necessary. Is the cable connected correctly?
Yes its hooked up correctly, and moves freely but will snap shut/off as soon as i let go of the lever.
Mr Brown
Registered
It shouldn't do that. It's a push/pull cable, should stay in place until you move it back. If it's snapping back it's in a bind. Probably responsible for your erratic idle as well.
There is a spring on the fast idle arm though, wouldnt that make it snap back just like the throttle does?
No Cott,it should stay at the rpm that you set it for,stay at that until turned off. I used to modify it somewhat and use the fast idle as cruise control. 
Shid you not,it works.
Rubb.
Shid you not,it works.
Rubb.
