This engine is a reed induction.But if a CDI was used or gas/glow it could run in either direction im sure.But as Ram Jet said if the timing was changed it could run.But if you even lost 8 OZ by losing the flywheel and using somthing else and lost about 4 OZ by gutting the muffler youd still have a 3+ LB -21cc engine.That is not good except for floater planes.