check the fuel pump, remove the hose that goes from the pump to the carb, check if fuel comes out after making the engine spin a little with the ingnition, obviously do this with someone to help you out, if fuel doesn`t come out then check if fuel is getting to the pump. if there is no fuel, then fuel tank is dirty or the fuel filter is too. if there is fuel before the fuel pump, but doesn`t come out on the other side, change the fuel pump.