View Full Version : Off Idle Stutter

Lands End
05-21-2008, 09:35 PM
Hi all, I Have experienced the 1000-3000rpm stutter, overheating and poor fuelling myself, on an 06 ULY and have improved the problem, 100%.

Here's how:

1. Check and reset the static ignition timing, (mine was set wrong at the factory).
2. Remove breather pipes from airbox, block holes and run pipes under bike or into a catch can.
3. Follow this proceedure:

With your air box assembly and base off, the TPS sensor is right on top of the throttle body. If your TPS has two orange dots, you have the new revision with the vertical alignment tabs. This procedure applies to the old style as well. Adjust both throttle cables so sufficient slack is available. Back off idle adjustment cable until the throttle plate will snap shut without touching the idle cable stop. With a scribe, mark the TPS position by scratching a single line from the throttle body to the TPS. This will serve as a reference point just in case. With a 7mm open end wrench, remove the two TPS mounting bolts and remove the TPS from the throttle body. Clean the debris from the back of the TPS and the side of the throttle body. Apply a small amount of high temp silicone grease to the tabs on the TPS to minimize wear in the future. Replace the TPS but leave the mounting bolts slightly loose and rotate the TPS full left (counterclockwise). Insure the throttle plate is totally closed, then rotate the TPS until you feel the spring make contact with the alignment tabs on the throttle plate. Rotate the TPS slightly clockwise to preload the mechanical zero position and secure mounting bolts. Most of you will notice that according to your reference marks, your new position is just slightly right of the old position. Now your TPS and throttle plate are truly aligned, without play. Connect all wiring and perform a TPS reset, just like the manual states.
Now you have a solid TPS zero.

My Uly is now picking up the front wheel in first, staying cooler, easier to handle at very low speeds and the fuel economy is now back up to 55mpg (english).

I hope this helps. If it does, please pass it on!


05-21-2008, 09:44 PM
Thank you very much!!!! I've been searching for ever found little bits of info here and there.. finally all in one place!!

Lands End
05-21-2008, 10:23 PM
Hi, markwoodlief,
I have read that you have done the 'square idle' fuel mapping mod, does it work? is it worth doing?
If you're having stutter prob, you may want to solve that too, to see any difference in low rpm driveability.

05-25-2008, 02:22 PM
Hey there.. I took yesterday to do all the steps you listed above..

Th square idle does work well but I'm currently running some serious datalogging and map adjustment so do not have it set like that at the moment, but yes it helps tremendously.

I still have my stuttering though.. sucks.. I've checked everything.. I've done mechanical tps zero, ecmspy afv zero.. rerouted air hoses to filter below bike,I checked static timing yesterday and its straight up..

I've also checked primary chain adjustement as that sometimes leads to a 'surging' stuttering issue.. it was perfectly in spec..

not sure what else to do.. Its seriously irratating driving through town and low rpms say between 2-2700 or so.. then righ at about 2900-3100 it's the worse.. i can feel it there no matter what gear I'm in.. with very light throttle only.. if i am reving through there its no issue at all..

Bike is fantastic all over great power, etc.. but just that stuttering persist..

Beleive me, I'm not just being picky.. I come from dirt bikes and KTM Adventure single cylinder thumpers so am used to a unstable bike, :) Thats just for all the buellers out there that say 'thats just how they are' I know that not to be the case.. I rode a friends a few days ago and although mines smoother and faster than his.. his didnt stuter goign through town..same bike..

05-25-2008, 02:24 PM
oh and i can always pick the front wheel off the ground.. and after remapping yesterday picks the front wheel off the ground in second as well... just throttle, no clutch or preloading.. :) I tried to wheely during every data log.. i figured If i'm going to log may as well have fun doing it!! :)

Lands End
05-25-2008, 03:04 PM
Hi Mark, I was hoping for a reply.
I trust you have taken it for a run at 70mph in top gear to reset AFV?

2 other things to try, Have you checked for air leaks around the intake joints?
The manual describes a test using a blowtorch bottle with a hose on it. I tested mine by squirting a tin of easy start around them while the engine was running. I found nothing, (Revs should rise), but at this point I had a few more warranty issues and took it back to the shop. They said that they were leaking and said they changed them. Initially it was better, but then the stutter came back. [mad]
The other thing to check is the exhaust valve cable.
Make sure the cable and the flap in the exhaust is free to move. When the engine is HOT make sure the cable at the top has about 6mm of sideways movement between the servo pulley and cable outer. The cable tension alters with engine temp so It has to be set hot.
I don't know where you live, I'm in the U.K.
We have a good forum with independent Buell specialists who have a wealth of knowledge to share.
Here is a link:UK Buell Enthusiasts (www.ukbeg.com)

Lands End
05-25-2008, 03:49 PM
I used mine all day yesterday at low speeds, up and down valleys, and round busy towns. It coped with the heat, didn't burn my leg, and by the time I got home, there was no stutter at all, even increasing revs slowly in neutral!

I think you need to run it for a while, maybe on std mapping.
If it's been fuelling badly, your O2 sensor will need to be cleaned up by running.

My stutter (and increased fuel consumption),(this is the soot that's coated your sensor), started after the first dealer service and TPS reset. I have suffered for 5000 miles with this, and the Physical reset has been the single thing that has made the improvement.

As you have ECMSpy, you know there is nothing wrong with any sensors, it must be just something set badly.

Mine ran bad after the mechanical reset for about 10 miles, (prompting a slight panic), but, after relearning it's AFV, it just keeps getting better!!

05-27-2008, 05:11 PM
Thanks for this post. Just got a 06 Uly and the surging-popping issue is already annoying. I am planning on at least re-routing the crankcase breather hoses but have some questions about doing that. In the do-it-yourself mod thread there is a nice write-up about how to do this and recommends putting a breather-filter on the hoses to keep the motor from sucking up junk. seems logical. However, should the drain line also be capped for the same reason and is there any issue with the breather sucking in water when riding in the rain ? Anyone's thoughts / experience on this would be greatly appreciated. After reading this thread I'm also planning on adjusting the TPS sensor.

Lands End
05-28-2008, 10:24 PM
Hi, riding tall,
I'm new on this forum, but established on the UKBEG site in the U.K.
I'm glad you like your Uly, It is now the best bike I have owned!
Regarding the breather setup, I bought some 10mm(3/8) silicone hose rather than rubber (withstands v high temps), and a 10mm brass tee.
The PCV's in the head's rotate to ease routing, but try to keep the ends pointing up to avoid slight oil losses.
Use the short Buell rubber breather pipe to block the holes in the airbox base, by passing each end up through each hole.(A free mod and the pipe cannot be sucked in to intake)!

According to my local vintage riders, as long as the breather tube is over 18" long, you will not suck anything up the pipe to reach the engine. My hose runs down between the rear pot and fan/frame and hangs down past the exhaust about 4" from the ground.
I did ford a river at the weekend with no probs, but I think I will move it higher out of the way.

Don't be afraid to ask questions: UKBEG has an independent Buell specialist, and has covered most subjects in the past.;)

05-29-2008, 11:44 AM
ha...some of you UKBEG guys were at the meet in belgium 10&11 may.


Lands End
05-29-2008, 10:57 PM
Hi LeFox, It seems UKBEG had a great time there! Thank you for the hospitality. I didn't go, maybe next year![up]

05-30-2008, 10:10 AM

06-04-2008, 03:38 AM
ok. I just did the re-breather part of this and ... WOW .. I did the breather mod more because I could than anything else but after having done it .. If you ride a buell and have not done this .. do it now. It make a big .. no HUGE difference in the idle to 3k range. I've only had one ride so far and there is 0% chance I'd ever un-do it. Odd thing is, If you had asked me if there was an issue before I would have said , some but rough running at low rpm but it's not bad. Now that it's smooth ... I think it was really bad. Thanks again Land's end and I did join UKBEG too .. thanks to the how-to's here , at badweatherbikers and ukbeg the re-breather mod was a snap. Oh and I did end up putting the breather under the seat near the tail of the uly to keep water out ... time will tell if that was a good idea.

Lands End
06-04-2008, 05:20 PM
Cool,I did this mod on my old XB12R, it worked on that too!
Thanks for you feedback. The rumour is, that it adds a couple of bhp, due to the fact that the mist from the breather doesn't burn.[up]