2008 buell lightening cityx xbsx with jardine gp1 exhaust is backfiring on idle

[CRSole]

Got myself a 2008 xb9sx with jardine gp1 muffler on it and it "backfires" like crazy starting it and just idling (technically fuel is exploding in exhaust so it isn't really "back"-firing back through intake but I've heard it called backfiring). Less than 10K miles on the bike. It didn't do this at the dealer I purchased from (of course). After purchasing I drove it home 200 miles in 12F weather, started it when I got home and it ran like absolute crap, misfiring, popping loudly into exhaust (scared the crap out of my girlfriend) so I immediately shut it off. I put it into heated 55F garage and put a battery tender on it overnight and tried the next day and it ran much better but still had huge exhaust popping...still scared the crap out of my girlfriend. I did contact dealer and they said it didn't do that there (of course) but they did admit to adding startron to fuel tank. I suspect they didn't truly "dealer prep" the bike despite my paying for that. Gonna try tps reset, extracting fuel, replace with fresh 93 octane and maybe seafoam and possibly change plugs. Also ordered buelltooth device because my thoughts are that it was never tuned. Also I'm looking for a stock muffler to be modified by hawk. I'm totally new to buells. Any advice on this issue?

 

[TPEHAK]

Check if injectors leak.

 

[Cooter]

You are on the right track for diagnosis. Let us know what you find for ECM settings and AFV value. Please resist making tuning changes for now. There is something wrong with the bike and it will need to be fixed before you open a whole new can of worms by trying to tune out a problem.

We can probably help you when you get some information. There are lots of smart and helpful members on here. Making assumptions about faulty parts (guesses) will only cost you time, money, and frustration...

Leaking injectors.

Your crystal ball tell you that?? lol.

It could be anything, even electrical, and the Buelltooth will help diagnose that too. In the meantime, check all the electrical connections especially grounds, and make sure all the physical connections in the exhaust (including the header flanges) are tight. Perhaps there is air getting in the exhaust causing the backfire? Pop off the airbox cover and air filter and make sure the intake snorkel and the lower rubber flange there are seated properly.

 

[lowkey]

First thing you need to do is get the bluetooth or USB connection to communicate with the ECM, observe the current AFV#and reset AFV to 100. Take the bike out for at least 30min and report back how much better it is now running along with the AFV# you now are seeing. Don't overthink it and start worrying just yet... it rode fine at the location you bought it, the ECM had calibrated to that environment (although it should have no problem with changing conditions as long as it is still programmed to do so... one thing comes to mind would be 02 sensor disabled within the EEPROM?).

OR you simply have an exhaust leak at the exhaust ports (possible broken stud/loose/blown out gasket), crack in the header, or leak at the collector-muffler junction.

 

[CRSole]

Wow! Thank you gentlemen! That helps a lot. Unfortunately I could not ride the bike before purchase as we had 4-6 inches of snow where I bought it from :-/ Also had that much or more snow where I live so I cannot actually ride the bike until the roads clear again (which could be any week now with goofy Iowa weather lately). I am looking into locating a stock muffler and having hawk performance repack it for performance. This is because I'm not a fan of the chrome look of the pipe and I was told that this pipe is almost a straight-through type and doesn't have enough back pressure to really improve performance and will in fact be robbing the bike of torque and horsepower. Unfortunately that will be a near $400 modification that I am not fond of right now, certainly not until I have the bike is running ok and I know there is nothing wrong. What are your thoughts on this Jardine GP1 with the goofy trumpet pipe out the side?

 

[lowkey]

Okey here is your problem "After purchasing I drove it home 200 miles", I was assuming you "drove" the motorcycle but in fact you have not. Picture this, a primitive computer controlled motorcycle is in one type of climate then awakens in a completely different one, it will run like **** until it can work itself out in its new environment... could turn out to be an actual problem i.e. leaking header BUT from your description so far I'm standing by it is simply environmental change at this point. Everything is speculation until you can talk with the ECM and report back with actual numbers.

As for that exhaust - not a fan of the looks personally

 

[lowkey]

Also would be worried about frame damage under that carbon fiber frame "skin" personally. All and all very nice looking bike but that tip is ridiculous IMO.

 

[CRSole]

Thanks and sorry for the confusion in my text. I'm in the Midwest in the middle of winter so test rides are just not possible, but these bikes seem to sell fast! I was looking at 3 and 2 others sold before I could even look at them (one 2003 with really low miles, like 4K was bought by someone way down in Florida!). I really like the look of the stock CityX bikes but I didn't want to lose my opportunity to ride one for another season. I've been looking for a few years but was unable to purchase until now. I'm not a fan of the exhaust and pipe at all and the modifications with the carbon fiber, while not what I really wanted (because I like the stock look), are at least tastefully done. I was not at all a fan of this muffler but thought I would ask on here to see what people know about them. If someone tells me they know they are awesome I'd consider riding as-is for a while but I am really looking to go back to stock exhaust. I wonder if it is worth trying to revert everything back to stock. From my looking, I think this bike was originally "kick ash", but it'll be really costly to replace the plastic to original and not sure if that carbon fiber stuff comes off real easy and maybe I don't really want to see what is underneath. I wish there was a reliable way to find out the history of a motorcycle. Anyhow, I appreciate the feedback and assistance on this as I'm pretty excited to ride one of these and be a part of the Buell bikes. I've been really enjoying just reading up on the Buell history!

 

[lowkey]

08 and up spark plug cleaning feature procedure https://www.buellxb.com/forum/showthread.php?37959-2008-spark-plug-cleaning

08 and up TPS reset procedure XB's and 1125's https://www.buellxb.com/forum/showthread.php?27480-tps-reset-w-o-ecm-spy

 

[CRSole]

Oh also, I got the cross referenced spark plugs to NGK DCPR8E from Auto Zone but have heard most use DCPR9EIX iridium plugs due to hotter spark and tendency to last longer. Which is best? In my bike's current state I just got the stock DCPR8E ones since they will probably foul in my fixing and tuning anyway.

 

[CRSole]

Wow thanks! I hadn't seen the spark plug cleaning feature procedure! That's impressive.

 

[lowkey]

9's are what you want, pull the boots and use a box - open for the front extension - wobbly for the rear.

 

[lowkey]

Also just to clarify I was only making a point of environment changes when I called the ECM primitive, 08 and up is DDFI3 and are more sophisticated than 03 - 07's DDFI2 ECM. You bike incorporates more data resolution and sensors. If it was me I'd perform those linked resets then if it will at least idle I'd let it idle up to operating temperature to get a better idea if it is working itself out. Even if you have an exhaust leak you shouldn't be causing any real harm (idling) unless you start revving it up in the RPM's leading to burning up the exhaust valves.

 

[CRSole]

Also just to clarify I was only making a point of environment changes when I called the ECM primitive, 08 and up is DDFI3 and are more sophisticated than 03 - 07's DDFI2 ECM. You bike incorporates more data resolution and sensors. If it was me I'd perform those linked resets then if it will at least idle I'd let it idle up to operating temperature to get a better idea if it is working itself out. Even if you have an exhaust leak you shouldn't be causing any real harm (idling) unless you start revving it up in the RPM's leading to burning up the exhaust valves.

Ok thanks. Yes it starts up just fine but pops or explodes out of the exhaust really loud periodically. I let it idle and warm up for like 15 minutes after it'd been in heated garage and on battery tender overnight.

 

[CRSole]

Also just to clarify I was only making a point of environment changes when I called the ECM primitive, 08 and up is DDFI3 and are more sophisticated than 03 - 07's DDFI2 ECM. You bike incorporates more data resolution and sensors. If it was me I'd perform those linked resets then if it will at least idle I'd let it idle up to operating temperature to get a better idea if it is working itself out. Even if you have an exhaust leak you shouldn't be causing any real harm (idling) unless you start revving it up in the RPM's leading to burning up the exhaust valves.

Also I probably would have thought the same thing about the environmental change and a rough start but since I have an Iron 883 with EFI with a similar engine and it starts up pretty good anytime, I didn't think this would be a problem. I guess I kind of figured the EFI system would completely compensate for the detected conditions. However, I am completely new to the Buell XB, so I didn't realize they are more tempermental; plus it is about 8 years older than my Iron 883 and I have no idea if this bike has been sitting for a long time or had or has anything malfunctioning. I can tell you I looked over the engine pretty well and it is very clean with no oil anywhere, but I guess I didn't inspect the exhaust manifolds and heads that closely looking for cracks :-/ Thanks again and I hope I didn't get duped!

 

[lowkey]

A simple phone recorded video from cold start to operating temperature would help as well, easily uploaded to youtube then just link it into this thread. This would help us all be on the same page as to how bad it is and help troubleshooting. Did you try again after those two procedures I linked?

 

[lowkey]

No worries, keep in mind someone could have fiddled with the ECM already so simply checking or unchecking boxes could render the ECM's ability to adapt impossible. I'm more familiar with DDFI2 but a general rule is after resetting a parameter, say AFV, you would want to ride for at least 30min for the ECM to start making meaningful adjustments again. There are other parameters that go into allowing for the ECM to make adjustments like operating temperature, sampling EGO against the fuel tables, etc...

 

[lowkey]

On the spark plugs, you could just pop the front boot off and see what plugs are already in there, the 9's are iridium and if they are already in you should be fine. I'd make sure they are tight at the same time though for sure, you aren't getting a torque wrench on them so keep in mind aluminum head and all... boots can be tricky to seat because of limited space but you should feel a distinct "click" when properly seated.

 

[CRSole]

No worries, keep in mind someone could have fiddled with the ECM already so simply checking or unchecking boxes could render the ECM's ability to adapt impossible. I'm more familiar with DDFI2 but a general rule is after resetting a parameter, say AFV, you would want to ride for at least 30min for the ECM to start making meaningful adjustments again. There are other parameters that go into allowing for the ECM to make adjustments like operating temperature, sampling EGO against the fuel tables, etc...

I will record a video later tonight and try to post it. True I really have no idea the state of this bike unfortunately. Makes me wonder why I paid $395 in dealer prep to Windy City HD / Triumph. I just got done sending email to them about that...after I made phone calls about the same last week. I just need to start troubleshooting but I don't get my buelltooth device until tomorrow sometime so best I can do is replace fuel, adding seafoam and changing spark plugs after that. Riding 30 miles is not possible due to snow covered roads :-/ Maybe I should hold off on all some of this until it can be ridden. I guess I could do the tps reset and spark cleaning procedures now if the fuel replace alone isn't the issue. I've gotta pick up a fuel extractor hose to do this. Thanks again!

 

[Cooter]

There is a very convenient 1/8 male pipe plug in the base of the fuel pump assembly to drain the tank:up:
Left side of bike, bottom of frame, just in front of swingarm. You'll see the 4 bolt flange and fuel pump wires. The plug is the off-set one.
But I imagine you put fresh fuel in during the 200 mile ride? Seafoam and such is nonsense (IMO). Proper injector cleaning requires removal, sonic cleaning, and testing. I don't believe you are to that point yet.

Remember what I posted about wasted time, effort, and money?:black_eyed:

If your fuel injectors magically plugged themselves (or started leaking) the day after it ran fine for that long, it's possible but I'd be very, very, surprised.
The ECM will correct for climate and altitude almost immediately. It doesn't take any external tuning to do that either. Still no need to get into tuning yet. because You have a problem that needs correcting. Looking at the AFV is a clue to what problem you have that the ECM is trying to correct for.

Lowkey is right. The PO is a mystery so there might be some monkeying with the ECM, such as a improper tuning locking out the self-adjusting properties of the ECM. Easy to check in the ECM peramters without adjusting anything once you get your Buelltooth in the mail.

I'm just trying to avoid this being a larger issue than you actually have. I'd like to see your Buell experience be the best, trouble free one you can have:applause:

This could simply be a matter of fouled plugs from an excited new owner starting it repeatedly in the garage without warming it up completely to show off a badass ride to his girlfriend....