If he wants to do a wheelie, tell him to do this: accelerate moderately in 1st gear to about 4,000 rpm, then quickly back off on the throttle and then nail it wot. The backing off of the throttle compresses the fork springs, and when you nail it, the springs rebound which puts the chassis in a position to do a wheelie. Make sure his arms are fully extended and sitting back as far as possible. If he wants, he could add some front brake during that short deccel to compress the front springs even more.
