backfiring in 5th at 120 kph (75 mph)

[Cmdrklassen]

While cruising on the highway for a couple of hours two days ago, I noticed the occasional backfire. it had been running fine for approx. 2 hours before this occurred. my rocket is mostly stock, the only performance related change I've done is remove the stock air plumbing and install the triple k & n's. My father and uncle own performance shops and say that you can change the intake system with no need to retune. only if you do exhaust change as well. They say the intake change will just allow the engine to breathe more and better. and if anything cause it to lean out a bit, not enrich it to cause backfiring issues.

 

[breeze]

I always thought running lean causes it to run hot,which in turn can cause other internal issues correct me if im wrong

 

[Mittzy]

I would put a better tune in anyway, send @HansO a message as he will be able to sort you out.
As for the backfire???? Maybe dirty fuel doing something funky or low tension leads to the coils, the spade terminals may require a bit of a squash to give a better connection.

 

[scot in exile]

You are correct you do not want a to lean engine

 

[HansO]

Stock Air Ducting is so restricted that it does in fact make a difference not a major one but it does make the bike run leaner, also how long has been since the Fuel filter has been changed, with the backfiring it can also be caused by a small leak at one or more of the joints in the Exhaust, anywhere from the head flange to the crossover pipe or the muffler joints, I would check those first
If you want a improved tune I can supply it just send me a "Conversation" with your email address and get yourself a TuneECU cable from here Diagnostic Interface for TuneECU Motorbikes then download the Free software from here TuneECU - Links