cutting the spark to prevent wheelie isnt going to cause a flame though . The only thing left is heat .
The only thing that will cause a flame to come out of an exhaust is unburnt fuel . Either on the overrun or on the power . It has not completed combustion in the cylinder so theres some thing left to burn . Theres nothing but heat left to set fire to unburnt fuel after it comes out of the cylinder surely.
i was going to say are you seeing wood instead of trees but that doesn't sound right…. the crucial difference is how does the unburnt fuel get into the exhaust…… in the video its because its set up wrong…. in the picture its because of the traction control cutting the ignition and the fuel still going in………..an ignition controlled traction control or anti wheelie are much softer than a fuel controlled anti wheelie…..research the 1098R versus the 1198s
I doubt they are cutting spark to all cylinders (in fact the fact that the bike is still wheelying that much even with wheelie control indicates the bike is still using most of it's power. My guess is that one cylinder has it's spark cut, or maybe two, therefore unburnt fuel is still meeting burnt hot gas on the way through the exhaust. I did think though with such tight restriction on fuel that they wouldn't dump fuel in when no spark, probably that the engine cuts the fuel and then in the exhaust you get a much higher 'clean' air ratio which is more likely to burn. I could be talking utter sh*te, any real engineers? In the case of the Video only, yes it's clearly over run, but I guess from high RPM there is still some fuel delivered and burnt on a closed throttle to deliver a smoother engine brake; either way these are pretty extreme circumstances highlighting the need to get the correct ECU or remap done. My Triumph used to sound like someone was firing a twelve bore behind me when I closed the throttle into corners, I have no idea if there was the occasional flame, I was luckily always facing forwards! it always had Triumphs correct fuel map for the Arrow can.
