Intermittent High Idle

Check for cracks in the intake boot

If its not an air leak as NSMAN has described it may be the main or other jets are partially clogged.

i had somethign similar on my '06 450 which made it rather entertaing going into tight corners.

i stripped down the throttle and cables - didnt help.

cleaned the carb - didn't help.

turned down the idle - went away.

couldn't see though how the idle setting would have cuased the revs to hang but thats what i did and it went away, whether it was coincidence i dont know but its never done it since.

Earlier Bergs have this issue if you run the idle at a certain speed and the ignition does not whether to advance or not, turn you idle down to the slowest it will comfortably idle and it should be good, a too faster idle makes them to hard to start anyway.
Best Regards
Sutto

very simple mate... takes no longer than 15 to 20 mins to get the carb off! but to check the jets you don't even need to do that! just take off the rubber boot from the filter and slacken the jubilee on the other side and twist the carb round a bit... you can get to all the jets from there! only you'll need to cut a 4mm allen key down to get at the bell mouth bolts! you'll see what i mean when you get to that stage!
cheers!
ben

I am having a very similar problem with my 04 FE650. Starts OK, idles OK just after starting, but after you have opened the throttle, even once, when returning to idle the idle will be high, or sometimes even too low.

I have just replaced the needle as the old one was worn, and gone over every other part of the carby.

I am thinking that it may be a worn throttle slide - or after reading a recent post, may even be the rubber ring worn on the slide plate. Those are the next two items i'll be checking.

Has anybody ever had to replace their throttle slide before or just the slide plate?

Here's my situation. I had my bike jetted over a year ago and don't know whats in there as I forgot
to get the info then. It was jetted for 2,000 ft and runs great there at almost 2 turns out. At 4,000 ft
I set it at 1 3/4 and runs good but idle starts droping to the point I need to turn up the idle screw.
What's happening here? Still too rich?
When I bring it down to sea level and at 2 turns or more idle rises back up.
The bike rides great with no problems except High Altitude low idles and lLow Altitude high idle.
Can someone explain what is happening? I don't have a problem with the low idle as it turns
up easy enough but I have a hard time turning up the low idle. It still runs good but is prone
to stalling
I have a feeling that my jeting is set for sea level to 3,000 ft and higher altitudes are getting out of my range. I have been experimenting a little by going leaner on the screw
and the idle seems to stabalize some. Go leaner at high altitude?
Pollo

pollo

you need to strip it, clean it and most of all NOTE it!

could say more but i think it would only encourage you to be a slacker!

andrew

put your hand over the tailpipe at idle. if you can hear a 'clock. clock......clock.clock' noise then the plate is ok. if you can hear it and you haven't even got the outlet covered then it really is worn. however i doubt that it's the reason for your high idle?

regards

Taffy

hanging idle and popping on decel are signs that your mixture is lean.

how long have you had the bike? is this something that it has always been doing or just started doing?

you might want to consider raising your needle a notch.

i've had this problem before on a ktm and it took a while to get it figured out but the previous owner had the vaccum release plate on the slide installed upside down which created an air leak.

the bike would also lean out in the winter and have similar characteristics and i would fix by adjusting the needle a notch. it doesn't sound right but the needle actually does impact how your bike will idle.

HMMMM, I'm having axcat same symptoms, Popping on decel, and interittent high idle that will drop after a couple of seconds. All this after renewing needle and atomizer.....

Today i tried 7 numbers lower and 10 numbers higher on the Pilot Jet, but with no real difference...... With all 3 differnt PJ's (50/40/33) the i get the best result with the mix screw all in, but still my idle wont work. Its either high after closing throttle for some seconds, or it will just stall.

Will try to raise my new needle (Now in pos 3), or fit the old needle and atomizer back tonight. Will let you knor my results

FYI this is Dellorto Carb

Anders, DK

Husaden said:

HMMMM, I'm having axcat same symptoms, Popping on decel, and interittent high idle that will drop after a couple of seconds. All this after renewing needle and atomizer.....

Today i tried 7 numbers lower and 10 numbers higher on the Pilot Jet, but with no real difference...... With all 3 differnt PJ's (50/40/33) the i get the best result with the mix screw all in, but still my idle wont work. Its either high after closing throttle for some seconds, or it will just stall.

Will try to raise my new needle (Now in pos 3), or fit the old needle and atomizer back tonight. Will let you knor my results

FYI this is Dellorto Carb

Anders, DK

Click to expand...

Did it ever idle and did the idle screw ever have a significant effect?

Does the throttle return spring snap the slide closed when you release the throttle?

Yes, it used to idle VERY sweet, and snap wheelies.... Don't know if the screw had effect as I never had reason to adjust. I changed to a new needle-set as it wasn't a good starter. Well it's a long story and I did quite a few thing to improve starting.... If interested follow this link:

http://husaberg.org/index.php?name=PNph ... 0191#90191

Soon on my way to the shed, to put old part back in for a tester.

My throttle SNAPS back, and has appropiate play in cable and no binding

Anders, DK

i'm afraid back popping isn't a sign of lean idle. it's not really proof of anything.

it could be that your ignition timing is wrong. a general rule is that the white line of the stator is central but wants to be 1 to 2mm to the left of centre.

best to get the REAL TDC with a DTI or using a 'stop' for the 'dead stop' method. mark with white tippex and then strobe on full advance.

do you have a CD1 jet in the carb? you can find details of this in carburation in the doc. look for it as a subject title and follow the link.

you may not have enough advance.

regards

Taffy

As the needle and atomizer wore so possibly did the slide where the idle screw presses against it to lift it for idle adjustment.

Remove the carb boot to the frame and turn the idle screw. If little movement is noticed that could be an issue.

Take the spring off of the idle adjustment screw and screw it all the way in to see if it will affect the idle.

I suspect that the worn needle was compensating for a worn idle adjustment screw and / or slide.

My 600 came from the factory barely able to idle. It was discovered that the idle adjustment screw hole was drilled improperly not allowing sufficient lift of the slide for correct idle. A used carb was found which fixed the problem.

Back from the garage, and VERY CLEVER !!! 8O

I now have the SWEETEST idle, the SNAPPEST wheelies, and SO MUCH more low end torque than ever !!! And did i mention PERFECT Start. And NO high or intemittent idle, and NO stalling And my adjusters now do wat they are there fore !!! Yes I am a bit exited right now !!.

Taffy told me to go leaner on the PJ, and "needle the needlel" the other day. I did not really understand why as just put in new atomizer and needle, so that would make it leaner on it self ??? My self thought i should go richer, so i got hold of a 50 and a 33 PJ to test against my 40. On the new needle i set it at pos 3, same as the old one.

I put Neddle/atom. at the same time as i got a new Taffy Torque cam in, that doen't make the faultfinding easier........

After assembly she needed a little throttle to start, but started good with that.

So all day i spent a lot of time testing the 3 new nozzles and mix screw an ALL positions.... Not much difference with any of the combinations, and I found it very stange that my idle screw did not seem to anything on the idle. With a setting for HIGH idle it would just give me the high intemittent idle after closing the throttle.... Very exciting round corners as one said. After a few secs. it would fall down to low revs again and almost stall. With a setting for low idle it would stall at a quick closing of throttle.. Also so very interesting riding !!! So NO GOOD Settings.

After reading MURAKAMIS post it made a lot of sense to me to go richer on the neddle. So I tried my old neddle/atom, which i thought was worn and RICH. No DAMN difference, but I learned that they where not noticable worn, and I just renewed them as they where not new to me !.So to go even richer I tried pos 4, again with all 3 PJ's. It was all worse now.
BUT I can only agree with Murakami that needle pos affects the idle VERY much, more about this now.

Then I thouhgt about Taffy..... Go LEANER he said.

So pos 2 was then tried.. now with PJ 40 again. SLIGHTLY better idle but still no real effect of my screws.

Then pos 1, and WOW. Now i could adjust my screws, and after i while i thought it was perfect.... Then tried my PJ 33. And WOW-WOW. Even better !!! Read the top 5 lines again !

What all this tells me, is the carbs are not easy, but when you are getting close you know ! Fiddeling with all the PJ's and needle pos did not make much difference, untill I came close to taget. Only then could i feel the difference on my adjustments, and actually adjust my idle speed. So rember that if your carb is way out, you might not get the effect you wanted untill you are close.... So if somone told you to go leaner and that didn't help, then try EVEN LEANER... That's what I learned today after having the carb apart 19 times, and countless adjustments

AND THE NEDDLE AFFECTS THE IDLE VERY MUCH (At least on my bike it did)

As for the popping I can only agree with Taffy again. When i went richer it got little worse, leaner only slightly less... But its still there, now i just enjoy it ! Fiddleling with the Ignition timing is the next thing, and getting that new needle/atom. in also.. I paid for it !! Maybe I need small adjustments again. And at sometime i will try even leaner just to see what happens. How can you tell it is perfect without actually over-doing what you are doing, and then move back again.... ??????

Happy adjusting


Anders, DK

Thanks Taffy,
The carb is coming off soon. It's probably about time after 100 hours.
And it will be good for me to learn, clean and know what's in there.
As for saying more, well i wish you would have
The more I know about the philosophy of these things the better.

pollo

anders

i suggest you go into the doc and look up jetting settings by joeusa. if you follow his guidelines you'll have another bike again.

i can tell you from experience that you will be chasing your tail until you drill the 2 air jets.

regards

Taffy