The measurement of the brackets securing the fuel tank is incorrect. Also, the structure of the bracket's section where the tank is secured with bolts is improper, and the torque of the bolt is inadequate. For these reasons, the tank securing bolt or the bracket securing bolt may become loose due to vibration during traveling etc. If left unfixed, a crack may occur on the fuel tank, causing fuel leakage, or a crack may occur on the bracket and in the worst case it may get damaged, causing the fuel tank to fall off.