I work/teach at our local airport in town and every now and then we get guys (usually squids) at the front desk asking if it's okay to use 100LL in their bike. We usually tell them "No, because it's not made for it." In reality they can put whatever they want in their bikes, we just advise against it.
Aviation fuel (or "100LL," "avgas," "the blue stuff," etc.) is leaded gasoline (the "LL" in "100LL" stands for "low lead"), so I'd guess that using it in an engine built to run on unleaded gas wouldn't be too good for it. It's dyed blue so it's not easily confused with Jet A, which is usually straw colored.
But yeah, 100LL does smell
awesome. 