High Idle

[vmax2extreme]

Hello fellow maxers, I've combed through the postings here and havent found anything to address my high idle issue. I recently swapped out my old stock upper throttle cables for the Motion Pro stainless steel upper lines. My bike is sync'd and the idle stays up around 1200 - 1400 rpm. The idle screw will not lower down the idle to 900-1000 where I usually keep it. I opened up the upper/lower cable linkage to see if there were a snag or something going on, but still the problem prevailed. Not sure what would cause the idle to stay high and not be able to be adjusted?

I know the shotgun is for not idling needed the choke to run, but what about with a high idle that wont come down?

What should I check since there appears to be no issues with the bike, airbox is secured down with no leaks and same with connection to intakes with the rubber boots. I do not see any cracked rubber boots on any of the 4 carbs.

Can anyone please give me ideas of what to check next to see why the idle is so high? All my carbs are in sync within 1-2 cfm.

This is a 2005 GEN1 that is ridden about 1000 miles a year. No changes this year to the bike.

Thanks for your help...

 

[Traumahawk]

I'm thinking something with the throttle cables. Either they are hung up....need to be adjusted....etc.

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[[email protected]]

I'm thinking something with the throttle cables. Either they are hung up....need to be adjusted....etc.

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Good though and easy to check. Disconnect at the junction and see what happens.

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[maleko89]

Check all 4 choke plungers and make sure they are all the way in when choke is off.


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[vmax2extreme]

I've already ruled out the new uppers as stated. I did mention that I opened up where the uppers and lowers connect to remove upper connections which there was still high idle with that out of the picture.

- ruled out sync covers since while all 4 carbs on the sync tool it still happens.
- My choke cables all seem intact and no issues, intake boots all intact.
- all intake boots all seem intact and not splitting anywhere

What else can be checked?

Thanks in advance...

I'm thinking something with the throttle cables. Either they are hung up....need to be adjusted....etc.

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[vmax2extreme]

I can see the choke is operating on all 4 carbs. How do you tell if they are all the way in when looking?

Check all 4 choke plungers and make sure they are all the way in when choke is off.


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[maleko89]

Attempt to push each plunger head in. It's what the little choke forks pull out. If it moves in then the linkage is in a bind.


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[Traumahawk]

Well with the cables being the last thing changed....it makes sense to start there. I've had binding before that was caused from where the cables attach to the carbs. I only found it by disconnecting everything again......and then reinstalling the cables.

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[vmax2extreme]

I only changed the uppers, not the lowers. I did remove the uppers to eliminate them and the idle is still high. I never touched the lowers at all.

Well with the cables being the last thing changed....it makes sense to start there. I've had binding before that was caused from where the cables attach to the carbs. I only found it by disconnecting everything again......and then reinstalling the cables.

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[maleko89]

I only changed the uppers, not the lowers. I did remove the uppers to eliminate them and the idle is still high. I never touched the lowers at all.

Remove those from the throttle box too. The cables may need to be adjusted. There's an adjuster at the throttle grip side and one on the pull side of the carb.


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[Traumahawk]

Ok....sorry about that I thought that you had.

Question......i don't have a manual right in front of me.....but is there a particular distance between the upper and lower cable in the block? Like a couple of mm gap between the two?

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[vmax2extreme]

When the uppers cables are separated, theres nothing but slack left in the lowers. I'll try removing them too, but doubt thats anything to do with it.

I wont have time tonight to do this task since its late here already and I dont want to disturb the neighbors. I'll report my findings back tomorrow afternoon.

Remove those from the throttle box too. The cables
may need to be adjusted. There's an adjuster at the throttle grip side and one on the pull side of the carb.


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[dannymax]

Did this issue start right after you swapped out the cables or did it work good for awhile, then the high idle started?
Is the return cable hanging up somewhere between the carbs?

 

[Killjoy]

I would take then uppers off the junction block and see if idle goes back down with just the bottom cables attached.

 

[Donny Daughtry]

Reach in with a finger and and see if you can pull the the idle tab down after disconnecting the cables from the junction box-if so then it would be a bent idle tab.

 

[vmax2extreme]

From inspection all appears normal with the carbs setup. I did notice when I pulled the carb rack, the vboost butterfly in the center wasnt fully closing due to the engine vent tube was rubbing up against it. Not sure if this could be the cause either.

Did this issue start right after you swapped out the cables or did it work good for awhile, then the high idle started?
Is the return cable hanging up somewhere between the carbs?

 

[vmax2extreme]

Already mentioned that that was the first thing I did and no change.

I would take then uppers off the junction block and see if idle goes back down with just the bottom cables attached.

 

[vmax2extreme]

At this point, then carb rack has been pulled off the bike and I've decided to order all new (8) boots since the bike is 12 years old.

Reach in with a finger and and see if you can pull the the idle tab down after disconnecting the cables from the junction box-if so then it would be a bent idle tab.

 

[Donny Daughtry]

At this point, then carb rack has been pulled off the bike and I've decided to order all new (8) boots since the bike is 12 years old.

I have worked on other peoples carbs that have laid them down directly on the idle adjustment screw and that bends the tabs-sounds like your was happening before you pulled them off if i am correct?

 

[vmax2extreme]

I have never pulled the carb rack off the bike therefore this problem was pre-exhisting, but I cant recollect when it actually started. So yes, this happened before it was pulled off.

I have worked on other peoples carbs that have laid them down directly on the idle adjustment screw and that bends the tabs-sounds like your was happening before you pulled them off if i am correct?