[stryder]

Sure, you can add pipes without changing anything else. Whether that will lead to a *too* lean condition depends. Slip the pipes on, take the bike for a *nice* ride, and if you don't hear or feel any lean effects, then you're okay. If you hear excessive popping on decel, or experience "carb farts" that cause stalling on acceleration, or if the revs hang up way too long after a blip, then you'll need to fatten it up.