Why would you want a pull start? I know it causes you to carry less gear around, but bump boxes are more efficient, pull starts actually rob your engine of horse power, just slightly. plus when the roller bearing shaft wears down, it can suck air through the rear cover and unintentionally lean your engine out.
End result, premature blow up!
Once you invest into a bump box, you'll wonder why you ever beat the hell out of your hands yanking on a stupid pull start. I actually wish i had some sort of starter on my lawn mower instead of a pull start.