The gasoline fueled single cylinder generator engines are well established and available in the market with reasonable
price, in the other hand the biogas fueled engine for electric generator is not well established yet. The purpose of this
research is to find simple conversion method from gasoline to biogas fueled of the single cylinder four stroke engines.
For this purpose, the biogas should be upgraded to the level of zero H2S impurity and zero level of H2O content. The
carburetor of the gasoline engine was replaced and only component of the mixer of the fuel and air were used. The
intake of the biogas fueled should be completed with valve that can be opened automatically by vacuum of the
suction stroke of the engine. To increase the performance of the engine, the liquefied petroleum gas (LPG) was added
to the mixture up to 80% of biogas and 20% LPG.