| Author | Message | ||
     Towjam |
I'm still going through the first 1k break-in on my 12Ss. However, I'm noticing a behavior with the throttle at low (or just of idle) speeds that has me concerned. A little background... Most of my riding has been on Harley big twins or BMW boxers. Both of those engines have smooth, even, power delivery at low engine speeds which makes parking lot maneuvers a breeze. On the other hand, my XB tends to be a little jerky and more than once, I've almost dumped her trying to navigate out of a parking space or starting off from a standing stop. Also, I'm noticing the engine surging slightly at lower speeds (like cruising through heavy traffic or through a parking lot). Would this problem be fixed with a TPS reset? Or is this just the characteristic of the engine? | ||
| Rubberdown |
Primary chain adjustment?  | ||
| Ft_bstrd |
Towjam, Have you had a TPS reset completed. If so, was it with the bike at 320 degrees? Many are getting bad TPS resets (not at operating temperature) and having problems with throttle response. It definitely isn't normal. ChadHargis hooked up TPS resets all around (4 Buellers) last weekend. I spent some time afterward practicing counterbalanced slow maneuvers, and it was like buttah! | ||
| Towjam |
I've not had any service work done yet - I was planning to waiting until the 1k service. But I've gone ahead and made an appointment for Saturday morning to have this looked at. Thanks for the replies. | ||
| Towjam |
ok, one more question (and apologies if this is a naive question)... If the problem were a loose primary chain or a the TPS was out of adjustment, is there any potential damage I could do to the engine or tranny between now and Saturday? I have the opportunity to do a 200+ mile ride tomorrow and I would hate to miss that. | ||
| Ft_bstrd |
I don't think there would be any problems. I can't imagine that the primary chain would be loose. Are you feeling any additional vibrations? When mine loosened a bit, I got a vibration at a particular RPM in every gear. A bad TPS/Throttle response wouldn't hurt anything unless it was WAY out of adjustment and you would notice more than just a snatchy off idle throttle response. If it isn't backfiring, hard to start or giving you lots of aberrant vibrations, I say hit the road and enjoy your ride. | ||
| Ft_bstrd |
BTW, nice profile pic (see mine). | ||
| Nasty73z |
My bike is jerky down low, my chain is within spec and god knows I've set the TPS enough. Think it is just the nature of the beast. | ||
| Towjam |
Ft_bstrd, The XB is totally stock and I've not noticed any strange (or stranger than normal) vibration - other than the rear views become crystal clear once you get a hair past 3k rpm. No problems starting and surprisingly, I'm not even getting any type of decel popping. The only two other items I'm keeping an eye on is that once the fan kicks in, it pretty much stays on the remainder of the ride; and, the idle (in my opinion) is still a little rough - according to the tach it's idling right a 1k but as it breaks in I expect both of these issues to work themselves out. Oh, I like your profile pic too - but when did you change it? I thought you had a pic of FB the last time I checked it out. | ||
| Ft_bstrd |
I change it periodically. Keeps 'em guessing! I would have them check the TPS at the 1000 mile and again at the 5,000 mile. Better yet, find a local buddy with the software and buy him a mexican dinner (currency of Chad).  | ||
| Naustin |
Depending on how bad it is, and how low you're pulling the rpms, it may simply be normal. The buell isn't tuned for extreamly low RPM like a Harley. Keep it above 2Gs minimum. If you're below that, it isn't going to be smooth no matter what you do. I think its because of the high strung cam, but I'm not an expert. | ||
| Roadrailer |
Just off idle? How low are we talking about here? Most bikes require some clutch modulation at/just off idle in order to be smooth. | ||
| Towjam |
Keep it above 2Gs minimum. If you're below that, it isn't going to be smooth no matter what you do. You've nailed it. Once I get around 2k, absolutely no problem. It's an issue between 1500-2000 rpm. Maybe I'm still not fully adjusted from coming off a Harley. | ||
| Tx05xb12s |
I think that's just the nature of our bikes. Under 2K mine does the same, especially if it's cold. I've noticed it runs a little smoother at low RPMs now that it's got over 9,500 miles on it. It also idles smoother now. I think a few thousand miles will be your remedy. And yes, my primary chain is within spec and I had the TPS reset when I installed the race kit. It just doesn't like to go slow. That's a good way to foul plugs too by the way. | ||
| Disturbed |
Nature of the beast. Low speed 1st gear "parking lot" maneuvering leads to bucking/jerkey behavior if you let it get close to idle with the clutch out. Use your friction zone on your clutch more. | ||
| Donl |
You need a TPS reset. I bought my bike in January and had the same problems. Ran like crap, I asked the dealer and he said it would be ok after the first scheduled maintenance. I took it in after 800 kilometers and they did a TPS reset. It made a world of difference. I plan to buy the software from Al in the next few months so that I can do my own reset. | ||
| Dick |
My 06 XB 12SS was exactly the same did smooth out some when I put the Drummer SS and K & N filter on and a TPS reset.So here is what we did to my buddys 12S went to the xb9 primary set up sprocket and chain it worked great but revs went up a bunch. Great in town but lost top end on the open road.He went back to a stock 12 set up just kinda like every one says nature of the XB12 bikes. | ||
| Xl1200r |
I'm going with the "that's just the way it is" camp. My 2004 Sportster, which for all purposes here, had an engine that was mechanically identical to the XB. It would do the exact same thing below about 2000rpm. Keep it above 2000rpm. That's just the way it is. | ||
| Deedub |
Towjam, while you're getting your TPS reset, have the AFV reset as well. I've got a 2006 XB12Ss which had the same symtoms, i.e. jerky at steady throttle positions under 3000 revs. Also check your injectors; my front one wasn't clipped to the throttle body properly. Ninety percent of my surging disappeared after the AFV was reset. | ||
| Jkhawaii |
my bike has been that way since day one. think it just a mater of big cam, with a lean emissions AFR.. and a 45deg V twin. | ||
| Towjam |
Towjam, while you're getting your TPS reset, have the AFV reset as well So that I don't look like (more of) an idiot when I'm at the dealer, what's the "AFV"? | ||
| Hogs |
AFV= Air Fuel Value | ||
| Swordsman |
Tow, I've got an Ss also, and experienced the same sensation. Everyone said get a TPS reset, AFV reset, yadda yadda. Had all that done, no difference at all. I think it's just the way the throttle works. During low speed maneuvers, it's twitchy as hell, making it jump around. I finally got used to it about 3000 miles in, and have much better control over it now, though it'll still lurch around if I'm not paying close attention to what I'm doing. ~SM | ||
| Towjam |
I feel a little better knowing that I'm not the only one who's experienced this. On the other hand, it's a little disconcerting to hear that on the one hand, I need a TPS reset, AFV reset, swing a dead cat over my head, etc. and then others say that they've done that with no benefit. Oh well, I'll have the dealer check it out and if they don't find any problems, I'll accept it as the nature of the beast and adjust my riding accordingly. (One of the service guys at my dealer worked for Buell and was on the XB development team. If anyone can pinpoint this, I trust he can.) Thanks again for all the feedback! | ||
| Naustin |
Towjam - As I said before it all depends on how bad it is. The bike exhibits the behaviour you're describing normally - and as others have said, this is just the nature of the beast and part of its character. Now that said, the behaviour would be wildly more exaggerated if the TPS is not properly calibrated. BTW - This procedure should take all of about 5 minutes from the minute you roll the bike into the garage, until they ought to be rolling it back out, so don't let them rip you off! The bike adjusts the AFV automatically for temperature and humidity and elevation, etc. every time you ride. So, even if the shop sets the AFV back to "stock", the computer will adjust it 15 minutes after you take off anyway. So, again, it all depends on how pronounced the behaviour is. And, as I said, the motor just wasn't designed for parade duty and even if everything is perfect, its not going to be happy under 2Gs. Keep the revs up and enjoy the bike! (Message edited by naustin on March 16, 2007) | ||
| Justin_case |
TPS reset is part of the 1000mi. service. The AFV is adjusted by the ECM. Changing it will make the bike run worse 'til the ECM changes it back! | ||
| Swordsman |
Resetting the TPS and AFV didn't help, but swingin' the dead cat worked like a charm!  ~SM | ||
| M1combat |
1500 is pretty low... I generally use the clutch at those RPMS. If you're in second or third you can cruise at 1700-1800 as long as you don't whack the throttle open or anything. | ||
| Ulyssesguy |
Have you considered getting a K&N filter, 07' Airbox and the 07' ecm program? I put those parts on my 06' Uly and it helped alot with the low rpm jerky surging behavior and it likes to rev easier now too... just my .02c | ||
| Kybueller |
I keep her in a low gear and above 2000rpm. Mine does al the stuff you mentioned under 2000rpm. I guess it is normal. Bike sounds damn good wound up anyways, so keep er up there. I love my Buell. KYBUELLER | ||
| Kybueller |
"Resetting the TPS and AFV didn't help, but swingin' the dead cat worked like a charm!"  | ||
| Snowhownd |
I bought my '06 Ss used last spring and coming off my first bike (a Suzuki GS500) thought there was something wrong with the Buell because of its jerkiness and uncooperative demeanor at low rpms - exactly like you describe - coming out of parking spots, red lights, etc. I did almost dump it a couple times as well when it jerked/surged suddenly. I'm completely used to it now though - it won't take long. Seems like these bikes just don't like going slow!!! Just enjoy it!! | ||
| Tootal |
The reason you jerk around under 2000 rpm is because the buell and the sportster don't have a compensator nut like the big twins. A compensator nut is two cams rubbing against each other under spring pressure and this takes all the jerking out of low rpm's. Without it you must stay above 2000 rpm's. A loose primary chain makes it worse. In other words: It's the nature of the beast! Ok, Buell, lets start putting compensator nuts or equivalent to make these things smoother. All in favor say I!! | ||
| Hogs |
compensator nut Not for me Thanks!!! Just another thing to go wrong, And I have seen them screw up before... Thanks ... But NO THANKS...! | ||
| Xb12s_streetdemon |
check your throttle linkage. make sure threr is enough play in it. you can adjust it how you like. i have about a half inch of play in mine and its smooth. when i took out a one of the hd owners bikes it had no play in it and i almost dumped it. and a friend of mine crashed another friends buell after he thought he would help him out and take the slack out of his throttle. he popped a wheelie and when he came down the throttle was so tight he jerked it again paniced. so check that. | ||
| Roo |
Hi, I have just bought a 2003 xb9 and was wondering if you guys could tell me how to adjust the primary chain, and how will I know when it needs adjusting. Thanks. Roo. |
