A mounting structure on motorcycle for protecting a capacitor from vibration and heat. In an engine having an upright cylinder a throttle body is connected to an intake path of the cylinder via an insulator, and the throttle body is connected to an air cleaner via a connecting tube. The throttle body is thereby elastically supported relative to the engine and a vehicle body frame via the insulator and the connecting tube. A capacitor is disposed at a position downward of the throttle body. The capacitor is supported integrally with the throttle body using a lower portion of a throttle body cover that covers both left and right sides of the throttle body. A vibration isolating support structure is thus achieved for the capacitor by using the throttle body that is elastically supported.