just give it plenty of throotle, lean back and find the balance point, on chinese bikes it is harder to pop monos, if u lean forward the bike goes back down, i got a mate that can hold a mono on his husky125 for over 500 meters, his dad wheelies his quad for like HEAPS, over 1 kilometer no joke, they are pretty in2 bikes, the kid has 12 of em at 12 years old! lucky ass,
wat bike u got? it usually helps to hav a light bike and plenty of hp, i don't weight enough to do a decent mono, plus i hav a pretty long bike, i can only do standing up monos, don't really do many but them i do i can't hold it up for long, maybe a second or 2