Buell Backfiring

[mplette]

My XB12SCg Lightning has on occasion begun to backfire while on the throttle,hesitate, and then stall out completely. When I restart the engine it immediately turns over as if nothing has happened.While in neutral I can rev it to redline,no problem. This will happen inconsistently,maybe every few months on average. Could it be the fuel,the line, the EFI? Any ideas?

[BuellPartsGuy]

Mine did that little hiccup kind of thing at intersections once and a while. Never really bothered me that much. I always was playing with the TPS adjustment and remapping but it always seemed to do it, mostly when warm.

[Leathercash]

I doubt it's anything serious, such as the timing. Mine also hiccups when I twist the right wrist a bit to quick at the intersections,then she almost stalls out but picks back up promptly. Then again mine only has 206 miles on it[smirk]

[v12tiger]

I had similar problem on mine when twisting my wrist too quick. I know its efi but it was like I was flooding it.. Don't know if thats poss with efi. Never bothered me though b/c I just wouldn't do it anymore and never anymore problems.

[mrdozer2you]

Hmm...could it be vapor lock? I've had that happen in my car on very hot days before.

[mezap]

I personally think its the pushrod valves with the EFI. I think that the EFI responds in a quick blip faster than the pushrods can open the valves, so you don't have as good atomizing of the air/gas charge. Just the nature of the beast. Course, this is assuming you have had your TPS set and shes good and broken in. But thats just my two cents worth, and hey! what the heck do I know? "I'm not a professional mechanic, and I don't play one on TV!" lol

[Jerry C]

My XBCity does this as well, I took it to a local tuner, they made it better. But it still happens.

[onelogue]

Have you replaced sparks at all? It can make a HUGE difference!

http://www.buellxb.com/buell_images/3100_20101201072618_L.jpg

[crxtasy169]

Reset TPS, check spark plugs or change to Iridium,Check plug wires, check coil, and check Crank position sensor.

Check all of these especially since 2008s have a lot of problems with crank sensors!

[Trill]

I had these same symptoms when I had a short to ground on the wire harness running from the ecm where the harness rubbed through on the negative post on the battery. It completely died and when I would hit a certain rpm it would sputter and backfire. I plugged into ecmspy which told me short to ground.

[Stevenc150]

More info, like Mods (intake or exhaust), re-route done, Year model, etc. BTW, what program did the tuner use, Directlink?

[Jerry C]

2007 XBCity no mods.Richmond Superbike did the tune, I am picking up my X1 from them tomorrow (tig welding on the can) I'll ask which program they use.

[MuSh]

I thought that was normal.

[Jerry C]

Define Normal!Richmond SB uses the power commander and some online tuning programs.

[Bloodybrains]

Has anyone tried replacing the TPS itself? They're a very common wear item on cars... You gotta think that it's moving everytime you pull the throttle..

My '06 12s does it when I blip the throttle at an intersection as well. I've learned to twist it smoothly.

Side note: EFI doesn't have a thing on the response time of a well tuned carb.

[Cosworth]

I imagine they fixed it by now, this thread is 4 years old.