Idle problem

[Iron Duke]

Am having a problem with a high idle (at just over 2 grand) know that the idle should be right at 950 to 1150, can not find a idle adjustment screw between #2 and 3 carbs, thought the problem was the 1/8 vacuum hose from under the CDI cover (where vacuum advance is I belive)that went to the #2 carb, hose had fallen off cut little off the tail and put back on, cranked it over it stayed right @ 11 hundred, went for a ride later today started off great but by the time I got 2-3 miles from home it would be reving at 2000-2100 at the stops, what the h is going on?

[natemoen]

Don't know what year bike/carbs you have but on the early models the idle adjustment is a big knobby screw that sticks up, I think the screw sticks down on the later models. Have you done a carb sync on the carbs? How did you initially set the idle?

[mack]

Year & model

Need more info. Did it just start or have you been tuning it or cleaning the carbs and can't get it back to what it was?

[Iron Duke]

Idle high

Natemoen, No big Knobby screw sticking up, what later models ? I have a 79 f with an added fairing from Yamaha.custom saddleman seat, Frame/engine # 2H7-021149(meaning) would this model have the idle adjust sticking down from under ,and between 2-3 carbs( would be nice to have a picture of it both ways).
Mack, Have just under 500 miles on it, got in may carbs syned and timing checked, all I did was run 2oz of seafoam thru it with a tank of gas seemed to help smooth her out a little, seafoam is part of my maint 2oz every 500-1000 miles in tank of gas....back at ya guys.

[SFerinTEXAS]

Not meaning to doubt the carb sync(which I do) but did you personally do it or are you relying that someone else did it. If you did it then you would know where the idle screw is, if you did not do it then do it. Because that is the most likely of the easiest answers to your idle problem. Sorry if that sounds ruff .I get that way sometimes.

[Poprock]

Carbs out of sync tends to make the idle hang high, then slowly go down. A fast idle may indicate that the throttle mechanism is hanging up on a intake hose clamp turned a little too far off bottom center. Can't see it, but it'll hang 'em up. Make sure all clamp joints are at the dead bottom.
Also, if there is any hint of stray gasoline (i.e.) fumes when the bike is sitting, engine off; signs of gas oozing over the sides of a carb or two, any hint of fuel leak, check your octopus. It too will affect idle settings because it can let in extra air, it sucks fuel through it's vac hose into #2 carb (ruining sync) it costs gas mileage, and it robs power. That'll show up as a slight stagger or hesitation when you twist it to accelerate.
My octy was leaking fuel like mad when I discovered that's what it was. Taking it out solved problems the bike has had with 3 sets of carbs, smoothed out the idle, took all the buzz out of the footpegs and handlebars at speed, the hesitation disappeared, and all the popping and backfiring went away. Other than that, I couldn't tell any difference. Cheap to check, easy to eliminate.

[SFerinTEXAS]

Unless the throttle cable is catching on a boot screw or is broken at the screw where it enters grip. but those problems would be always present not just after a run.

[mack]

Ya I would

pull the tank back off and look closely at how the throttle cable is run. Make sure that it fully closes when you roll the grip and let it go. Should here a metal on metal "tick" sound. With the tank off have a close look between 2 + 3 carb tops. If it's a 79 then the idle adjustment knob barrel should be evident between the two and the knob itself will be toward, and facing the airbox side. Whoever sync'd for you may have adjusted your idle mixture screws and could have leaned them out on you by mistake during the sync. I don't let anyone touch my ride but me for this very reason. This goes double for bike shops.

[natemoen]

If the bike is new to you and you have never needes thw.odlw screw and now you see its moot there, a PO could always have "forgotten" it...

[Iron Duke]

idle problem

I found the Idle adjust knobby headed screw on the back side between 2 and 3, to late tonite to tinker so will have to be later in the saturday,other than the idle being fast ( after warm up) I have no problems with the ol gal she can still kick *ss, smooth throttle up all the way ,I back off after 100, hoping after I take the Idle down it takes care of my problem thanks guys.