I hope someone can help out here, a mate of mine has a '05 soft tail Duece chopper, it has a Thundermax aftermarket ecu with autotune, its exhaust is a Vance and Hines big-radius 2-1. It also has a full breather air cleaner but is otherwise stock. The tuning program he is using on his laptop is Thunderheart from Zippers, and the basemap he has in his module is HBUSSXSGUG040108 . Ok, now onto the problem, when he blips the throttle when downshifting it pops out of the aircleaner quite loud, it will also do it occasionally from idle if you give the throttle a quick blip. Looking at the realtime readout on the computer the only thing that seemed out of place to me was the base timing advance seemed to be rather high, 15 degrees but I have no Harley experience so I'm not sure what they are standard. Other than the pop out the intake the bike runs sweet the plugs are ever so slightly dark but they are still tan right on the tip, so the mixtures are somewhere close.
