Drag racing isn't really something 2 strokes were designed for. However, when racing I did have to lauch from the start every time, and found that hovering at 8000 and feeding the clutch to maintain those revs was the best start - you're just into the powerband so the motor is less likely to bog down but also has the most revs available so you have time to get your feet up and into second before the limiter.
That's an on MC21 mind, but the 18 will be similar.
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball