| Author | Message | ||
     Werewulf |
ive been looking at uly's an beemers pretty intensly...the uly is the best bang for the buck by far, but will the moco ever step up to the plate and release a race ecm or a cure for the 08 stumble issue....is there anyone in the "incrowd" with any scoop? | ||
| Natexlh1000 |
They issued an Eprom update. My mileage jumped by about 5 and the power is improved a great deal off idle. This was common to all 2008 XBs I think. | ||
| Tipsymcstagger |
but will the moco ever step up to the plate and release a race ecm or a cure for the 08 stumble issue....is there anyone in the "incrowd" with any scoop? The off idle stumble is one of my biggest pet peeves. For what it's worth, I had a long discussion with Al of American Sport Bike a few weeks ago. Al is extremely knowledgeable about all things Buell. Much of what he said is very technical and was skimming off the top of my head. But in Al's opinion, the off idle stumble is inherent to the design of the Buell fuel injection system. Al can explain in much greater detail, but the gist of it is that the Buell fuel injection uses a single large throttle body as opposed to two smaller throttle bodies, which would be more complex. Because of the design, the FI has to be a "jack of all trades," meaning it needs to perform throughout the RPM range. The large size is necessary to provide the volume of air necessary for top end performance but at the expense of performance elsewhere in the RPM range...namely, off idle. If you were to decrease the size of the throttle body to improve the off idle characteristics, you'd suffer at the expense of reduced top end performance. As I said, Al's description is a lot less nebulous. I'm an engineering degree dropout. Switching to business fit in much better with my college beer drinking program.  But that said, I still think the vehicle should run perfectly as delivered and I anxiously await a solution. Tipsy | ||
| Natexlh1000 |
Gotta disagree with you there. My X1 is sick right off idle to redline. (throttle wheelies from 2500 to 6000 RPM) The 2008 is weird with a separate idle bypass circuit. The throttle plate is allowed to close completely at idle. The 2008 software patch cured it pretty much. I'll bet that it will be refined a bit here and there from this point out. Now that mine has 6000 miles on it, it's running better and better. My X1 didn't feel "right" till it hit 12,000 miles. | ||
| Tipsymcstagger |
Gotta disagree with you there. My X1 is sick right off idle to redline. (throttle wheelies from 2500 to 6000 RPM) Let me clarify; by off-idle stumble, I'm not referring to acceleration under load. Put the bike into first gear, launch, accelerate and the FI works very well. The condition I'm describing occurs when advancing the throttle while the engine is not under load...while it's in neutral...what some people here like to call "blipping." Some have suggested the way to deal with this is not to "blip" or not to apply throttle when the bike is not in gear. I respectively disagree. That is not a solution to the problem. That is simply a way to mitigate or avoid seeing the problem. If my leg hurts when I stand and the doctor tells me the solution is not to stand, this does not correct the ailment. It simply eliminates the symptom. Tipsy | ||
| Crusty |
Why do you think it's necessary (or even a good thing) to blip the throttle when the bike is at an idle? | ||
| Tipsymcstagger |
Why do you think it's necessary (or even a good thing) to blip the throttle when the bike is at an idle? Crusty, I don't think it's necessary. And I don't think it's good or bad. What I do think is that when an engine is running properly it should not stumble, regardless of whether or not it's in gear. If you don't ever give a twist of the throttle when you're at a stop-light, fine. I guess you'll never notice that the engine stumbles when gassed off-idle. Does that mean the engine is perfectly tuned? What if I loosened all of your handle bar riser bolts and told you as long as you don't ride the bike, it won't be a problem? You won't see anything wrong when looking at it from five feet away, so I guess there's no problem with the bike, right? I really don't want to debate this ad nauseam. I don't believe a properly tuned engine should stumble when gassed under no load. Tipsy (Message edited by tipsymcstagger on August 15, 2008) | ||
| Werewulf |
the factory updated flash is in my opinion, a placebo! my tubers and even my 03 xb9, were smooth as silk.. sure, you wont have an issue if you launch at every traffic light at 5k rpm.. i keep hearing that you must let the bike warm up, before you try and ride it...what other fuel injected bike requires this?..surely not the earlier models.. i think that American Sport Bike is probably right, that its in the design... if so, then its not ready for prime time... either its individually bike specific and all the 08s dont do it, or the owners have never riden another year buell and dont realize there is a problem... the buell xb platform is really amazing, in the engineering details... why would they turn loose a flaw like this into production... i see on the xb section of the forum, that one of the members claims to have solved the problem with ecm spy... however, if American Sport Bike is giving up on a solution, that speaks volumes.... it sure would be nice, if someone could corner erik buell and just ask him what we can expect... | ||
| Red_chili |
I don't have a stumble off idle, with or without load. I would not say it is inherent based on this. I *used* to have a stumble off idle. With or without load, and unpredictably so. More than once it left me coughing on a hard acceleration, which I would regard as a safety issue - or at the least, embarrassing. I am not running the stock fuel or timing maps. (Message edited by Red_Chili on August 15, 2008) | ||
| Tipsymcstagger |
I don't have a stumble off idle, with or without load. I would not say it is inherent based on this. I've emailed Al and asked him to contribute to this thread. Maybe when he has a free moment, he can add his two-cents. Tipsy | ||
| Red_chili |
Let me just clarify, I do NOT claim to have 1/10th the knowledge Al has. I am probably doing something wrong. But I like it.  I fiddled with the accelerator pump emulation. Under the guidance of others. It isn't perfect, it is a big hole to fill with very little vacuum, but it is much much better. (Message edited by Red_Chili on August 15, 2008) | ||
| Longdog_cymru |
Stumble off idle? Yes, we all blip the throttle, but does an "off-load" blip really cause that much grief? If it stumbled while pulling away under load, I'd say "get it sorted", but a slight hesitation when opening the throttle off-load in neutral? Come on guys!!!!! | ||
| Tipsymcstagger |
Stumble off idle? Yes, we all blip the throttle, but does an "off-load" blip really cause that much grief? If it stumbled while pulling away under load, I'd say "get it sorted", but a slight hesitation when opening the throttle off-load in neutral? Come on guys!!!!! That's where we'll have to agree to disagree. Tipsy | ||
| Ulyranger |
I too fail to see how an imperfect, no-load blip on a FI'd engine is important. If it stumbles under load, that's another story. | ||
| Longdog_cymru |
Getting back to Werewulf's original question..... I came from a R1150GS to the Uly. Yes, there are things I miss from the GS, the main thing being the super-duper, no-dive front suspension on the GS and the fuel capacity. On the other hand, the quality of components on the Buell are better, the engine (on my '06) is superb, the gearshift is lighter and more precise, I could go on, but most of all, the Uly makes me smile more!!!! (The Uly is also more economical on gas and oil too!). | ||
| Werewulf |
where did the blipping throttle thing come from? that has nothing to do with stumble problem... anyway, the GS seems to be a hell of a bike, at a hellava big sticker price... i owned 3 beemers and did my own maintainance of them... the xb sure has the beemers beat in that category.... | ||
| Ulyranger |
Werewulf, as to your OP, not all 08s have exhibited a "stumble" in the powerband. My 08 has run fine since delivery and gets better with each mile. Yes it suffers from the typical Buell imprecise throttle below 2k, but no stumbles, hesitations, misfires, etc.... I can get my XT to putt to about 10-12 mph w/o difficulty, anything slower requires finesse. I will get the updated eprom done for extra mileage and if it improves anything else it'll be a bonus. | ||
| Tipsymcstagger |
where did the blipping throttle thing come from? that has nothing to do with stumble problem... Werewulf, if that's not the problem you're describing, I don't know what off-idle stumble you're referring to. My '08 accelerates smoothly in gear. There is some jerkiness while coasting at extreme low speed, but that's because first gear is so tall. Tipsy | ||
| Al_lighton |
Just to be sure that we're referring to the same thing, I'll re-state what I think Brad was referring to when we talked. If the bike is at idle between 950-1100 RPM, and you blip the throttle, there is a 1/4-1/2 second gap between when you twist it and when the engine spools up. I've experienced it on every XB I've ever played with, and I've never been able to make it go away with changes to the fuel, spark, or accel maps. It doesn't particularly bother me, as it is a condition that doesn't really affect how the bike should be ridden, IMHO. The tuber FI bikes don't seem to do it as much, and my Mikuni carb equipped S1W doesn't do it at all. But the XB's all seem to have that 1/4-1/2 second gap from the time the throttle is twisted until the time that the engine starts spooling up in a no-load condition. It is purely speculation on my part that it is a throttle body size issue. But throttle body size DOES impact velocity, and it seems entirely plausible to me that intake air velocity and momentum effects could be responsible for that off-idle transient delay. And that is one difference between the carb/tube frame FI bikes and the XBs... the throttle bodies got much bigger. There are other complaints that folks have about stumbling/coughing/surging that are NOT was I was discussing with Mark, and I think they have nothing to do with throttle body size. The closed-loop surging that many experience is real, but varies on it's intensity from bike to bike. Similarly, coughing back through the throttle body is hardly unheard of, but I haven't had a big problem with it, and I usually only see it as an issue during warmup. But the small gap when blipping the throttle from idle seems to be pretty universal from my experience. Al | ||
| Tootal |
First gear to tall? Really? Will somebody please put a 6 speed in the damn thing so I can ride in heavy traffic without abusing my clutch!!!So I can go off road and make tight turns without abusing my clutch!!! Sorry, didn't mean to highjack, I was just glad to see someone else say what I've been saying and needed to vent!! I feel better now. | ||
| Werewulf |
thanks for the info... the stumble that i was plagued with, was when you went to take off from a light and it felt like it might stall, but usually didnt..you had to give it a lot of throttle and give it a bonzai launch to make sure it didnt quit... i see an 07 uly at a dealer on consignment and maybe i should go that route, as ive havent heard any complaints on 07 model driveability issue... like i said, my 03 xb never missed a beat... i have a brand new xb9 sprocket for an 08 model sitting in my shop... i had every intention of putting the lower gear in a new uly for some good torque... tallahassee bmw quoted me 23k otd on a GS adventure and thats a lot of bucks... you can almost buy 2 ulys for that much money....decisions, decisions! | ||
| Electraglider_1997 |
You can probably buy 3 06' Uly's for that 23K. | ||
| Werewulf |
al, is there any relief in sight? | ||
| Xbimmer |
But the XB's all seem to have that 1/4-1/2 second gap from the time the throttle is twisted until the time that the engine starts spooling up in a no-load condition. Is it possible that with the uneven firing cycles of the 45 deg v-twin the ECM delays the start of things until the timing sensor tells it that things are ready to go, in order to optimize fuel efficiency (therefore) power delivery? | ||
| Red_chili |
If the bike is at idle between 950-1100 RPM, and you blip the throttle, there is a 1/4-1/2 second gap between when you twist it and when the engine spools up. I've experienced it on every XB I've ever played with, and I've never been able to make it go away with changes to the fuel, spark, or accel maps. It doesn't particularly bother me, as it is a condition that doesn't really affect how the bike should be ridden, IMHO. What really bothered me was the stumble on hard acceleration from low RPM. Sometimes it did it, sometimes it didn't; it was the unpredictability of it that I found especially bothersome. If it were carbed, I would have cranked up the accelerator pump a bit. Coincidentally it would not take a blip off idle unless it were a small one. Interestingly, my Honda XR650R behaved similarly (but not to the same degree). A pumper carb relieved both symptoms. In the dirt, blipping is an important function and often used (most of you know that I'm sure, I'm just babbling). In my case at least, now I can blip as much as I want (I know, meaningless posing or something), AND accelerate hard from almost any (reasonable) RPM. I can only suppose that Buell's hands are tied by the EPA, or they would fix it. Hard for me to imagine why accelerator pump emulation happening more instantly would bother the EPA, but then, there's a lot of things in this life I don't know. Here it is if you want to try it. I fiddled with Greenamp's maps he posted a while back (reason for the filename). No warranty express or implied, use at your own risk, not for highway use, yadda yadda:  | ||
| Red_chili |
BTW, that is on a non-race ECM. Don't know if there are differences here, just sayin'. I also backed off the cold start enrichment from that displayed, to good effect. Try THAT with a Beemer. (Message edited by Red_Chili on August 16, 2008) | ||
| Blk_uly |
just ride it! the more you beat on it the more it will love you It likes to be beat on and it seams to respond accordingly. I will admit it did have some stumbling, studdering'coughing, and yes even stalling! After the reflash(mabye i was lucky)the symtoms were totaly manageable. After that I did have some problems with the exhaust valve, the actuator cable and the actuator but all were replaced under warranty for which I am greatfull to Buell for taking care of. However, I would'nt trade it for a fleet of it's competitors! Their are no words to describe how it makes me feel When I ride it. I can't describe the satisfaction I get When I twist the throttle. the front end becomes light, the motor groans then whamm it pulls like an angry mule! yeah thats why I ride a buell. because it's got character,guts,moxy,whatever you call it I love it. I think you all need to remember what it's all about and stop focusing on whats wrong with it. i | ||
| Werewulf |
i did, quit focusing on what was bugging me on my 08xb... i traded it for a roadking, with flawless fuel injection, problem solved.. however, i still would like to have a uly, if i can just find one that runs properly..ive alway had at least two bikes.. thats why im always broke.. | ||
| Buellsrule |
Silly, silly thread. If "blipping" the throttle and getting a stumble while in neutral bothers you, sell the bike and find something that runs perfect in your driveway. Good grief!  | ||
| Tipsymcstagger |
Silly, silly thread. If "blipping" the throttle and getting a stumble while in neutral bothers you, sell the bike and find something that runs perfect in your driveway. Good grief! Hmmmm...thanks for the advice. I don't have a driveway though. Do you have any other suggestions? Tipsy |
