This paper presents the design and test of prototype of Disk Brake Dynamometer of Single-cylinder engine performance standard Brake horsepower with water using the Honda GX-200 four-stroke 196 cm3 gasoline engine, 1-cylinder gasohol 95 fuel. The experiment result showed that the Prototype of Disk brake Dynamometer maximum engine torque was 11.58 N m at 2500 rpm. The maximum power of engine was 3.29 kW at 3000 rpm and maximum thermal efficiency of engine brake was 25.36% at 2500 rpm. When being compared the performance of a standard single-cylinder engine performance test with the all-purpose gasoline engine Honda GX-200 1-stroke 4-stroke 196 cm3 gasohol 95, it was found that Maximum engine torque was less than 5.39%, the maximum engine power was higher than 2.49%, the maximum fuel consumption of the engine was higher than 10% and the maximum thermal efficiency of the engine was higher than 2.39%.