just tried to fit my graupner sonic prop to my os 91 and the hole in the prop is to big for the engine spindle. is there some kind of spacer i need
thanks phil...

If the hole is only slightly larger, you can wrap a layer or two of tape around the shaft

I use the KS brass tubing from the hobby shop as a bushing. I cut a piece slightly shorter than the prop is thick.

You can cut it with your razor saw. It will not dull the saw