Acetone is an organic solvent and has properties that are very different
than gasoline.   I wouldn't want to even ride in a vehicle whose fuel lines
have been exposed to acetone----you just can't know what the effect of
small amounts of acetone in gasoline might have on those lines.  I'm
already pissed off about the additive changes that have been made to
gasoline, and the extent to which the driving populace is a guinea pig for
the trial of these materials.
  Engine fires are not fun events and it seems you should do everything
possible to prevent one.  That should include not experimenting with
solvents on fuel lines.
Don