THE Consumption of fuel oil has increased in line with the increasing needs of the community and industry. The increase in the demand for petroleum fuels is not offset by Indonesia's oil supply. Because of this, there is often a scarcity of fuel oil in the regions of Indonesia and the resulting fuel price hike. The most widely used fuel in Indonesia is the type of diesel fuel. With the occurrence of scarcity in diesel fuel, then, look for an alternative that is biodiesel, which utilizes coconut oil and castor oil. This study used one-cylinder diesel engine connected to a generator to power a load of 5 lamps with each 500watt load. The test parameters are specific fuel consumption, power and injection characteristic testing. The results showed that biodiesel fuel B5 and B10 were lower than diesel fuel. For fuel BKBJ 91 B5 and BKBJ 91 B10, those have better power than other biodiesel fuel at each loading that is 2596 kW and 2,504 kW. For fuel consumption (SFC), the biodiesel mixture of B5 and B10 is lower than diesel fuel or more efficient than diesel ie BKBJ 55 B5 0.169 Kg / watt.jam and BKBJ B10 0.163 Kg / watt.jam at 500watt load. In spray characteristic test obtained biodiesel fuel B5 and B10 have long spray than diesel. For biodiesel fuel B5 spray is slightly diffuse, for B10 has a spray that centered into the pond.