Lawnflite 548 Tractor Mower Problems?

I have a Lawnflite 548 Tracor Mower and when I start it the cutting bladed turn even when the Blades are not engaged. Anyone any idea what would be causing this. As it's driving me crazy!!!!! Also to start it I need to use jump leads as it doesnt appear to have enough juice to get it started. I think this is because of the problem of the blades rotating on start!!!