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Another Hanging Idle thread

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I just traded my 450X for a nicely equiped '02 plated 650R. I haven't been out on it just up and down the street. It seemed that on the test ride it ran great but I thought the guy had the idle set a little low. Yesterday, I fire it up, turn the idle up a bit and run in down the street. It won't idle down now. The only way for it not to hang is to have the idle set very low, where it barely runs. What the hell?

Yes, I did a search and I know what the first response is going to be, throw away the stock carb and go with and Edelbrock. #1, thats not an option as I don't have $400 burning a whole in my pocket and #2, I've owned two other BRP's and they all worked flawlessly with the stock carb. The bike is fully uncorked, 68s pilot, I forget what main he said was in it. Any ideas?

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1. Make sure that the throttle grip returns all the way when you let go of it.

2. Lube the throttle cables to make sure that there's no problem there.

3. Clean all external carburator linkage to completely eliminate any mechanical problem.

4. Go get some Amsoil Quickshot gasoline additive and put as much as is recommended into a fresh tank of gas, and then go for a long ride. The Amsoil product is astounding stuff. If there's any gum or varnish in the carb (likely since a bike that's up fore sale isn't likely to get ridden), it'll disolve it handily.

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Sea Foam is also a good additive to try before taking the carb apart.

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How many turns out are most guys running their pilot screw? Turning the screw out is richening it up right? I've got a 68s pilot. Thats all I know, just picked up the bike. I really haven't ridden it yet but up and down the road. Trying to figure out this idle thing. I'm going to check my pilot circuit tonight.

Edited by pb1963

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Like Ruger said, eliminate the throttle cable as a possible source first.

While idling, turn the bars back and forth to make sure a cable isn't pinched between the fram and gas tank, etc. The idle will change while you are twisting if it is.

Then, turn the fuel screw out 1/2 turn. That is probably all that it needs. No need for a different carb.

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pulled the tank and seat, no cables hanging up. I did check my fuel screw, mine was 3 1/2 turns out. That sounds like a lot when the previous post said I only need a 1/2 turn. My question now is, this is a fuel screw right, not an air screw? A hanging idle, if caused by a jetting issue, is a lean condition right?

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You aren't confusing that the 1/2 means a half.,,It in fact .means one or two turns out,,though I dunno if that's correct as I don't have a 650r manual..Should be at least one and a half turns out anyway.,full 360s,,not half turns,.

I call it an airscrew..,Have you checked that it has all its parts attached,,ie,,Spring,,metal washer,,rubber washer..Personally I'd recommend you get a new one and install it,,then you know it has all the bits , The one you have may be missing some parts.,Checking for the parts on the one you have may be difficult as the rubber washer always seems to stay in the hole when you remove the screw..,Torch and a dentists type tool will be needed to check the orifice for the metal and rubber washer.,

and yep,,check for an airleak by spraying some ether (engine start) around the carb as the bikes idling,,Any change in tone indicates it's got an airleak somewhere around the carb,,and as Bajabinder says,,,Clean all the little holes on the sides of the pilot jet and blow the circuit out with compressed air,,In fact check the main as well.,.Holes on the sides of all jets and emulsion tubes must be clean,,Put a strand from a wire brush through the lot..

Edited by Horri

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pulled the tank and seat, no cables hanging up. I did check my fuel screw, mine was 3 1/2 turns out. That sounds like a lot when the previous post said I only need a 1/2 turn. My question now is, this is a fuel screw right, not an air screw? A hanging idle, if caused by a jetting issue, is a lean condition right?

Yes, fuel screw.

Yes, it's caused by a lean condition. With that many turns out, I would say you have a partially clogged idle circuit. Or, you have a vacuum leak.

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You aren't confusing that the 1/2 means a half.,,It in fact .means one or two turns out

Actually I am confusing it then if that is the way you describe it. I would have thought one or two turns would look like this: 1-2 turns. I think LearDriver meant a half turn but who knows:excuseme:

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Actually I am confusing it then if that is the way you describe it. I would have thought one or two turns would look like this: 1-2 turns. I think LearDriver meant a half turn but who knows:excuseme:

I know,,Bit confusing ..,If it said 2 -1/2 it means two and a half..

If it said 1/2,,It means one or two..,Dunno how your supposed to do fractions correctly on a keyboard.,All I know is it won't be just a half turn out,,somewhere between one,,two or two and a half is normal for the Hondas,.Start at 1-1/2 and work out to 2-1/2..shouldn't need any more than that.,

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Yes, fuel screw.

Yes, it's caused by a lean condition. With that many turns out, I would say you have a partially clogged idle circuit. Or, you have a vacuum leak.

:bonk::thumbsup:

And make sure it's a 68s,, a standard 68 is different on the emlulsion holes size.

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I finally got to tear into my carburator last night. I think I found the source of my hanging idle, it had a 65s pilot in it, not a 68s. I put a 68s in it but I can't comfirm that it works since now I have an issue with my float or needle valve because gas is pissing out the drain tube and its running like crap. I pulled the needle valve out and found a little piece of something on the tip of it. I was hoping this was the cause of the problem, that the needle wasn't seating all the way. Nope, still pissing gas. Any ideas? :smirk: I'm going to pull the bowl off tonight again.

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I guess I should have said float valve, not needle valve. The one that works with the float.

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So I ended up tearing down the entire carburetor and cleaning it this weekend. Put it all back together very carefully. Here is what I've got now, 68s pilot, 175 main, B53 needle 3rd clip from the bottom and fuel screw out 2.5 turns. Bike is fully uncorked, full FMF exhaust, side panel opened up.

So after getting it back together my hanging idle is definately better but it still hangs some. Maybe I'm just used to the FCR carb on my 450X that I've been riding for the last 3 years. I wish I would have researched the AJCV more before I took it apart. Can anyone give me some results on this mod, I tried searching but it seemed more of a "how to" than anything. Maybe I will shoot BWB53 a PM. Pictures would be good too?

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If its not a lean condition or a vacuum leak, its the carbs throttle slide valve and bore are wore and the vacuum from the motor is not letting the throttle slide valve return to fully closed, idle. I guess thats why the FCR's have wheels on the slide. I've read on here that some people lube the slide, works but not a permanent fix. another thing people do is polish the carb slide and bore, seems to work sometimes. Can you hook up a extra return spring. good luck

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