Soak the turbine where it slides on the shaft with some penetrating oil and holding the turbine with one hand tap [TAP not hit with massive force] on the shaft with a hard poly hammer or a brass hammer. Thats what I would try. If thats not enough a puller might be in order but make sure you soak the shaft with penetrating oil.
Are you talking about the flywheel - it has curved fins and it turned by the starter (pull-rope) assembly ? If so, I believe you will need a "puller" to do this properly without damaging the flywheel or the air cooling fins ... any Honda service techs out there ... please correct me if I'm wrong. Hope that helps -
im sorry i did not edit my original post. my knowledge of small engine anatomy is not quite up to snuff. loquin is absolutely correct in that it is the impellor, and not "turbine". im sorry if that caused any confusion. I will let everyone know how getting it apart turns out. Thanks for your help everyone.