Recently installed an S&S high flow air filter with Airstream cover on my 2012 XL1200C, and after about 200 miles it started to hesitate at low RPMs at speeds below 50. Occasionally when it does this it will cough from the intake. Performance on roll on or over 50 is fine, and the bike has no other mods. I haven't done the obvious... stick the stock filter back on and see if the problem is solved, but any thoughts before I yank it? ---Erik

 

sounds like she is running too lean. remove your spark plugs and check the color of the ground strap and electrode they would be white or have no color at all wood look new. the stock engines run lean for epa regulations . you gave the motor more air flow and that is causing your hesitation concerns you will have to add some type of fuel management. to correct the problem

 

Yeah, both plugs (but especially front cylinder) are pretty white. Rear cylinder plug a little more like it should be...may be discovering another issue. Beautiful bike BTW.