Abstract: The aim of this project is to investigate the effect of high refractive index material coating on piston head of a two stroke petrol engine. The experiment was based on comparison of Performance & Emission characteristics of a two stroke petrol engine (0.81 Kwh at 5500 Rpm) with a conventional piston and modified piston (coated piston head). Performance parameters such as brake power, specific fuel consumption, volumetric efficiency & emission parameters such as HC, CO are calculated and compared for conventional and modified piston engine .The resultant values are plotted for