I honestly don't know. We fueled up the plane, primed the engine, put on the glow starter and turned the prop with a chicken stick and it snapped almost in half. I had the prop resting where the instructions said to put it. I'm not sure why it broke. Maybe because it was a brand new engine, and they're hard to turn over?

Can you link me to the right size spinner and a backplate? Or do the spinners come with backplates?