Something to be aware of with engines is a practice called desaxe. The crankshaft is often set very slightly to one side of the centreline of the bore in order that the thrust face of the piston has some relief from the bang pushing it sideways against the resistance of the rod. If you spin a 2 stroke backwards, it means the other side of the piston gets the load, and receives more of a shove than it was designed for. It probably isn't going to be terminal (over the years 2 stroke cars have been started backwards instead of fitting a reverse gear), but it is something to be aware of. The picture threads cover just about all methods of fitting. Lutz made a lengthways kit that sat with the crankshaft 30-ish degrees out of the horizontal, and turned the drive 90 with gears to the final drive sprocket.