| Author | Message | ||
     Xb9er |
XB9R with airbox mods (XB12 cover, K&N filter, snorkel removed), new NGK plugs, stock ECM, stock muffler, stock motor, synthetic oil and pri/trans fluid, and 94 Octane gas. My TPS has not been reset since the above mods were done. The problem I am experiencing is after I have come to a full stop, when I blip the throttle (just slightly) or start to take off, the engine will Cough once. It isn't loud like a backfire, but for a split second, it almost feels like it's going to stall. It happened to me yesterday at the gas station when I started the bike up after a fill-up. Anyone know what causes this? Anyone have the same experience with their bikes? How do I fix this problem? I want to eliminate my Bike's annoying Cough... Thanks in Advance. Mike. | ||
| Easyflier |
A TPS reset isn't necessary with what you've done so far but it is checked/reset at some certain scheduled service intervals. Maybe you're overdue? | ||
| Fullpower |
perhaps your idle speed is a bit low? make sure idle speed is 1100-1150 rpm. | ||
| Bomber |
sounds like you need to set your low speed jet to approx 1.5 to 2.5 turns out . . .. oh, wait, isn't FI sposed to take care of this? I'd get yer TPS checked/set | ||
| Tucsonxb9s |
I'm set up the same and haven't experienced any of the symptoms you have. I'd get her checked out. (or maybe some Robotussin DM?  ) | ||
| Spiderman |
you may wanna try another gas station? An turn the idle up a tad. | ||
| Fst_tyms |
TPS | ||
| Downundabueller |
In my corner of the world the cough happens to me when I use a high density high octane(98) fuel called optimax by shell. One particular brand of high octane(98) eliminates this, in our market its called BP Ultimate. If I run on 92-95 Octane it pings like crazy but does not cough. I think we use RON for octane, do you guys use RON or MON. | ||
| Jasonxb12s |
Hey 9r, I have the same thing happen to me all the time. I've been riding a 12s for 2 weeks now and it does it at 50% of the lights I stop at. I've changed gas stations and that doesn't do anything to solve the matter. Everything on my bike is stock which leads me to beleive that your mods have nothing to do with it. Furthermored my bike idles at the recomended rpms,,,so I think I'll try sticking a bananna in the pipe next. I am having service done on Tuesday and will update you if they have a solution. Unless you figure it out before then, and please let me know. Jason oh, and I'm using 93 octane fuel.... edited by jasonxb12s on April 16, 2004 | ||
| Wyckedflesh |
if you are at the low end of the idle (1050) bump it up to 1100/1150. It will get rid of that stumble. | ||
| Xb9er |
Wow, thanks for all the helpful responses everyone. 1. Gasoline used is 94 Octane (RON) Sunoco Ultra. BP Ultimate is available, but BP's in this area used to put in about 10% Methanol which is bad. They made lots of changes to all their stations recently and added BP Ultimate so I'm thinking I need to check on the Methanol content again and maybe try the Ultimate if it's Methanol-free. 2. Idle speed is set at about 1100. I will try cranking it up slightly to 1150 rpm. 3. About the carb jets, how do I....oops, wrong bike!! 4. TPS reset. I knew TPS reset was not required with my minor "mods" but Easyflier is correct that I am Overdue. I'm thinking this is the culprit but I will try the other fixes first. Crap!!now I might have to bring it in to the dealer sooner than I wanted to!! JasonXB12S I'll let you know how things turn out in a couple days. All in all, I can live with a problem/annoyance like this which most likely is an easy fix once I figure it out. I just love XB's!!!  Thanks again. Mike The Badweb is BAAAD!  | ||
| Curtyd |
I have experienced momentary hiccups or losses of power just off idle also on my XB9S. I am working on the theory that I am the source of the problem. Here it goes, I believe 20 years of carbs on bikes, that I always am blipping the throttle at idle and carbs work well with this on a mechanical plane. Now I have precisely metered fuel injection with a computer mapped curve and all and it just doesn't stand up well to all this throttle signaling. It wants to be turned on and pull against a load, evenly. No blipping, sloppy movements, no loading up the intake passages with extra fuel. I will let you know how my own experiment with self control of my throttle hand effects this aberrant hiccup behavior. PEACE. | ||
| Blackhat |
I'm kinda with Curtyd. If I pop the throttle, then roll on as I let the clutch out, I experience the cough or pop randomly. Same when downshifting during the decel. I've noticed that if I roll on rather than "pop" on, the cough is pretty much cured. Doesn't seem to be an octane issue, rather a small backfire into the airbox. I've always associated this with unburnt fuel in the cylinder igniting when the valve is open. Maybe more of a bad fuel/weak spark issue. I'm no guru, and always open to suggestions. Could it be the gap setting? Blackhat | ||
| Xb9er |
Now that is interesting. I'm prone to throttle blipping myself. Note to self: "Roll on...Roll off." I had thought about spark plug gap also. My NGK plugs are set at 0.035 as recommended in the Buell Service Manual. But the gap setting (I just checked on the NGK site) recommended by NGK for my Plugs in an XB9R is 0.04. Seems like that may be part of my problem. Mike. | ||
| Stainlessmag |
Ive noticed the same thing on my xb9, but i have to agree with blackhat, if i blip the throttle slightly and quickly i get the pop alot of the time. If i just roll on the throttle no pop | ||
| Curtyd |
Yeah, i rode two-stroke street bikes, RD's & RZ's, for over 5 years, you just HAVE to blip those throttles. It's probably where the bad habit originated. I still have a 1978 RD over in my mother's condo garage and I have to get it over here and start tearing into it. It's a great around town bike. A little extra oil in the gas tank and the traditional HD folks just HATE having me putter thru their parades.  | ||
| Fullpower |
is there a possibility that you are using the wrong fuel for your climate/ compression ratio? these XB engines are only 10:1 compression, maybe the owners manual is correct, and 91 octane fuel is more appropriate. wont cost much time or money to try it. good luck. | ||
| Jasonxb12s |
Problem solved....I rode about 80 miles today and had no coughs whatsoever. I didn't blip the throttle at all and feel that is the reason. | ||
| Xb9er |
Cool Jason.  Mike. | ||
| Slowby |
intake leak? | ||
| Xb9er |
I set my idle to 1150. And I did what Jason did (stopped blipping the throttle) and the problem is gone!! Mike. |
