After the biogas information was collected and analyzed in 2013. We decided in 2014 to target our work at using the household or self-production biogas as fuel for the small engine or the motorcycle engine; Suzuki Skydrive 125CC, with Discharge Pump Fuel Injection (DCP-FI) system. However, the engine was not controlled by Engine Control Module (ECM); the original compression ratio and ignition plug of the engine were not changed. The engine was placed on the metal frame as shown in Figure 8 to ease the movement. Firstly, gasoline was fed to the engine from the gas tank on top of the frame, the engine was started and we found that it could work properly. Then, the LPG tank was placed on the side of the engine and connected with the gas reducer (inside the red circle on Figure 8) to reduce the LPG pressure. The gas from the gas reducer was sent to the premixed chamber (inside the yellow rectangle on Figure 8) and mixed with the air from the inlet air tube (blue PVC tube on Figure 8) where we fully opened the valve of the inlet air tube. After all connections were completed, the engine was started and we found that it could work properly. Finally, the engine was taken to the household producer in Moo. 1, Chiang Krue municipality, as shown in Figure 9. We disconnected the gas tube end at the LPG tank and connected it with the main biogas-draining hole of the producer, the biogas was delivery from the biogas tank to the gas reducer directly. The Air-(Biogas) Fuel ratio of the DCP-FI engine was investigated by feeding the biogas to the engine and, soon after, the engine was started. Our first attempt, we fully opened the valve of the inlet air tube, was failed. Our next attempt was begun by narrowing the inlet air valve and the engine was started, the attempt was successful, the engine could be started and operated as long as we fed the