Due to the rather thin mix ratio I doubt it will do any harm. Problem is I doubt it would do much good at such a thin ratio either. I say thin because regular mix ratio's for 2 stroke oil is from 1:16 to 1:50. So at .25 oz. to the gallon that would be 1/10th of the 1:50 ratio, thin. Using a additive designed for 4 cycle engines would provide adequate lubricity at 1:400 ratio or 1.28 oz. to 4 gallons. You would be using just slightly more but getting better lubrication along with additional benefits like cleaning up the fuel system and helping with water contamination.