Scooter kicks and bucks

[Blu]

when taking off. Only at low speed, but it kicks like a mule sometimes. I'm new to these things, I've only had it for a couple months. I'm guessing there is a remedy for this. Anyone?

Guess I ought to add some detail! It's a 2005 CF Moto, 250cc with 2500 miles. I have put 400 miles on it since I got it, and it's done this since I bought it. It runs and rides great, just this kicking at low RPM bothers me. I have an extra belt that came with it.