Exhaust and air filter mods

[Greg33]

I have a 2009 XB12R Firebolt and put a K&N intake filter with a Jardine slip on exhaust. It backfires a lot and fouled my plugs quick. I replaced the plugs and that smoothed her out some still backfired on decel though. I don't want to damage my engine and everybody says its running to lean so I was thinking I could put the stock intake air filter back on so the computer can compensate for the exhaust. What do you all think?

 

[Lesley]

Running lean will not foul plugs. Blipping the throttle will. That air filter more than likely is not your problem either. I have no answers about the Jardine but I don't see how that would foul plugs either. But after all the modding was complete setting there revving the motor and listening to the muffler WILL foul plugs. just my .02

 

[nazark_18]

You should tune your bike after changing the intake and adding a muffler. Not only will it smooth the bike out it will incorporate the modifications that you have done, and make your bike utilize the extra air flow to its fullest potential.