In the solar-biomass hybrid renewable energy system, the fuel supply for the spark ignition engine needed to be flexibly controlled because of the large variation of syngas-biogas-hydrogen compositions. Mixture preparation with a traditional carburetor is unsuitable due to the large difference in the air/fuel ratio of syngas compared to biogas or hydrogen. The technology of fuel injection on the intake manifold with a large nozzle diameter is suitable for syngas but not appropriate for biogas or hydrogen; However, it is contrary with using a small nozzle diameter. The combination of using 2 nozzles with 4mm and 6mm nozzle diameters is appropriate for Honda GX200 engine fueling with a syngas-biogas-hydrogen blend. When increasing the biogas or hydrogen composition, the injection duration of a 6mm-diameter injector decreases, while that of a 4mm-diameter injector maintains the maximum value of 130CA to 70% biogas or 50% hydrogen, then decreases. The reasonable injection pressure is 1 bar.