Not sure about your m/c But starters on cars, use a solenoid to switch the starter motor on, but also push the gear to the flywheel. I assume yours uses a different method, but all it can use, is movement, ie it starts to spin, gear, on a rotary spline, moves to connect with flywheel,( as it trys to stay still. due to momentum) But new starter, should be ok, make sure that the start gear is free to move. Does your engine turn over freely, Check alignment, if you can manually push start gear onto flywheel. Does it engage or maybe hit solid metal.
SD, February 2012