Ive had the fuel line quick disconnect coupler leak when I didn't get it connected perfectly. I'm talking about the part on the left side, rear of the tank, where you would expect to see the petcock on a carb bike. The leak was barely noticeable but if I put my finger under the elbow it would have a drip there. Otherwise, I would suggest pulling the dash panel and check to see if the hose on the overflow is disconnected, allowing the expansion fuel to pour down onto the frame and under the seat.
There is also a 1/4" plastic line the goes from the throttle body (right behind the air cleaner) across the top of the motor and back along the underside of the tank and then follows the cruise control cable down behind the frame and into the charcoal canister below the battery area. This plastic line is in at least 2 sections (maybe 3) and has rubber hoses connecting the different lengths. If one of those rubber hoses breaks, you will have fuel vapor escaping out, although I'm not sure if it would be noticeable unless it was in a garage or something.
2006 FLHXI Street Glide
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