[Gogar]

It happens to me on my Triumph every few years as the POS Amal carb goes out of round, and the slide sticks at the top. Reach back calmly and turn off the key, no prob.

I almost crapped my pants though the first time it happened. and once, with a lady on the back and her leg was sort of blocking the spot where the key is. She thought I was getting "FRESH".