Ok, so I took my 2009 Nightster out and it ran fine. The next day I take it out and it runs fine for about 10 min. on the road then at stop lights starts sputtering. After that it starts sputtering at highway speeds and losing power and then gaining it like it's surging. Finally it dies at a stop sign. I'm able to ride it back home and after that it never runs right again. I start it up, it backfires black smoke.

My first thought was bad gas since it had been sitting for a while with ethanol gas in it so I drain the tank and then put non-ethonal gas in it with some sea foam. Still runs terribly. I haven't been able to take it out of the garage because it keeps dying right after start up. It will run then start backfiring black smoke and finally die with a puff of white smoke out of the air cleaner. I just replaced the battery because I heard these issues occur with a weak battery (it did finally die so it needed on) but still same issues. Tonight a flame shot out of the air cleaner. If anyone has any suggestions I'd greatly appreciate your input!

Has DK air cleaner, drag pipes and x14ied.

 

how are your plugs?

 

Does your fuel pump sound normal when you first turn on the key?

 

Yea, the fuel pump sounds normal.

 

the plugs looked fine to me but I haven't taken them back out since the smoke and flame out of the air intake… I'll take another look at them tomorrow.

 

Also carefully check all electrical connections around the intake/injectors and the crank position sensor down by the oil filter. Check for the famous corrosion in the fuse box too. Did you do any repairs, mods or maintenance just before the trouble started?

 

Two winters ago I found myself having fuel issues [cloudy, from moisture], and it seemed to have gone bad overnight. WTF. So I drained the fuel and put a gallon of fresh high test and fired it off. I had to keep wringing the throttle while it continued backfiring and coughing out the intake for no less than ten minutes until it f-i-n-a-l-l-y started to get smoother and smoother, until it was running normally. K-ripes.

My thoughts were that the bad fuel was causing the information sent from the O² sensors to be whacked out, and as the ECM was interpreting this it was trying to compensate for the correspondingly less than stellar combustion/ignition, while the ignition system was trying to light everything off through water soaked spark plugs, and when it DID finally decide to light off there was too much fuel and some over pressurization and it came out wherever it could in a fog or a flame [through the heat of compression]. Then when the proper fuel was introduced, the spark plugs eventually lost their moisture, and the ECM again had to take the values coming back from the O² sensors and use those values to return the ECM values back to where they were before...I think, now I have a headache, LOL.

The above is just conjecture on my part but I do know that it took a surprising amount of time after adding good fuel for the engine on my bike to run worth a $hit. Whether this is similar to your situation I dunno, but start it up and keep blipping the throttle lightly [just enough to keep it running, don't OVER REV it] to keep it running and see if it clears up.

If not, take 'er out back, have a small ceremony, then pop a cap in 'er...it's all over.

Just kidding!

I hope you get the situation resolved.

=8^)

 

No mods or maintenance, took it out it ran great. The trouble started the next day when I took it out. Just kind of came out of nowhere.

I just put some more good gas in it with some sea foam to see if that'll help. It keeps dying at idle so I'll give it gas to keep it alive sometimes when I give it gas it gasps and then does nothing and finally dies with a puff of smoke out of the air cleaner.

 

Electrical problem. Might the control module.

 

Sounds like you've run enough good fuel back through the bike to flush-out anything that might've gone stale. How are your XieD connections? Anything come loose, or apart...might want to even disconnect them to rule out the aftermarket-parts. Good luck.