Why does additional octane enrichen the fuel system? Doesn't the fuel injectors Duty cycle remain the same? The fuel regulator hasn't been adjusted to run a higher fuel pressure? The fuel pump hasn't been changed to create more volume? Isn't octane the method for avoiding detonation/knock and having a more efficient burn in the cylinder? So, I don't understand how additional octane would cause a rich condition? Anyway, I had a little 104 left and ran it thru the lawn mower, ran like a champ.