Massive backfiring

[Rebel_CafeRacer]

I have a hawkpipe and K&N airfilter. My bike has recently developed a backfiring problem. It happens when I roll on the throttle between 1500-2500 rpms, the bike backfires so bad that it kills the motor. It starts up just fine afterwards. I tried doing a TPS reset by running 10min above 3500 RPM. The problem is still there.
I think one of the baffels broke free inside the muffler and the lack of proper backpressure is causing it. The bike seems a little slugish as well. Do you think I should get an ecu with a racemap from EBR, or go straight for sending the muffler back to Randy?

 

[redbolt04]

Either go for the race ecm from EBR, or get ecm spy and do it yourself. The combo of less back pressure and a much more free flowing air filter is causing you to run lean.

 

[Macbuell]

Depending on what year your bike is... When I shipped my exhaust to hawk I disconnected and sent him my ecm also. He put his custom tuned map onto my stock ecm for me. Runs great.

 

[rrh481]

It could very well be the ECM. Or one of your spark plugs could be fouling put causing it to load up with fuel and igniting in the exhaust. I had that with my jardine I put a tune on my exhaust witch helped but then I switched to NGK iridium plugs and that also made a difference

 

[Rebel_CafeRacer]

fouled park plugs huh? I'll have to check them out. I didnt even think of that. I guess it could be that, and it seems like it could be getting worse.... Could quite possibly be.

 

[XBwolf08]

First thing and say this to everyone , is it a backfire or exhaust pop. two did things. Backfire it is coming out your Carb , very bad thing . popping it coming from your exhaust not so bad and all the things that they are tell sould help either . but If is a true backfire have someone look at it , there might be more damage.

 

[rrh481]

^ true I just assumed he meant exhaust popping.

 

[Rebel_CafeRacer]

exhaust popping - the exhaust is igniting inside the muffler.
I didnt know it wasnt called backfiring, makes since when you think about it though. I guess thats just what i have always called it wrongly.

its an '06 xb12ss, so its not carburated...

 

[XBwolf08]

I am a old hot rod guy . I had carbs blow apart .

 

[Rebel_CafeRacer]

nice! bet that sucked!

 

[BuellerPilot]

The backfireing is most likely a result of your muffler and K&N. You've changed your air flow and exhaust dynamics and need to compensate your tune. It could be other things as well compounding the problem like plugs, plug wires, ignition etc. But you do currently have a miss-tuned engine.

Love the Diamond Blue, sorry we never got to work a deal out but it looks like it worked out good for you in the end!

~Mike....

 

[Rebel_CafeRacer]

thanks for the comment Mike, I got my rims off ebay from pinwall for a good price when i had the money, so it all worked out in the end.

The puzzling part of my problem is that i rode all last year with the exact same set up and its just doing something different now.

 

[gtp3800]

my friends bolt did this with his jardine can ALOT. so he sent his ecm to someone to tune it and when he got it back it still happened. but it was much less harsh and it didnt cause any problems anymore.

 

[BuellerPilot]

If it's a new problem, it could be a number of things. Plugs, plug wire, loose ignition sensor, Bad igniters, bad coils, bad fuel, clogging fuel system, intermittent wiring on either the fuel, or ignition systems, even a loose baffle in the exhaust can. Start simple and see what clears it up. However, you still are running an incorrect tune for you bike. If you replace that K&N with a stocker you'd be much closer in tune because the Hawk mufflers aren't really a big performance mod, more of a sound mod. Running the Hawk and stock intake probly isn't far enough off tune to be a problem mind you still not optimal. Running the Hawk with a K&N and your running close to the edge of really needing a tune, though you could still get away with it. Again, it's probly another problem compounding the lack of tune. Fix the problem and see if the current tune (of lack of) is livable.

I got my front Diamond Blue from Pinwall as well!! lol. I ended up with a full set of Diamond Blue, a set of Amber in fair condition which I restored to probably a 9 out of 10, and now have a brand new set of Amber's (10 out of 10). I can't find or convince anyone to unload/trade their Hero Blues. So I will keep my brand new Amber's and get either the Diamond Blue or used Amber's powder coated to Hero Blue. Haven't decided yet which set then sell the other set lol.

~Mike....

 

[Rebel_CafeRacer]

Ok, heres the update. Replaced the muffler and airfilter back to stock, and replaced spark plugs. Its still missing, but not as bad now, the bike doesn't die when it misses and chokes, and pops. Next step is replacing the Battery and seeing if that helps. After that I guess i will move on to Intake Air Temp. Sensor. After that, i guess i will move to the fuel system. I know the fuel here in Italy is crap and cloggs up fuel lines and filters, but i dont believe it would be this intermittent.

Any other Ideas?

 

[Rebel_CafeRacer]

MMMM- Also, It started and as soon as i opened the throttle it died. I was reading about the DDFI and how it operates in a closed and open loop. This leads me to beleive that either the IAT sensor is bad or the ET sensor. The fan turned on as soon as i turned the key, and acted like it didnt want to shut off. It was sitting in the sun, and its a little warm today (75*) but it seemed odd that the fan was running. Dont tell me that means ET sensor... that looks like a royal B!+@H to replace. As if the sparkplugs arent hard enough.