You can get an extra speed boost at the start of a race by performing the Jump Start.

When the Race Countdown appears onscreen before the start of the race, hold down the A Button. You must press and hold this as soon as 3 appears.

Now watch the Countdown and when it changes from 2 to 1, release the A Button for half a second before pressing and holding it again to start. You must keep the button held until the race actually starts for the jump start to work.

The easiest way to fail is to press the button more than two times in total or to not keep it held until you are in motion.

The rhythm of the Jump Start is:

On 3: Press and hold A button
On 1: Release A button (how long you release for doesn’t matter- it can be quick or up to 0.5 seconds)After Release: Press and hold A button and keep it held down until your kart is moving.

Keep the button held normally for driving after the Jump Start