Somewhere in the process of fitting my 750's cowl, I let the spinner/cowl gap get pretty narrow: about 3/16" or so. (Yes, I used the "donut" method, but something went awry along the way!) Fortunately, it was a nice, even gap!

So, while a tight gap looks great, it makes it difficult to get the cowl halves on-and-off without scratching them against the spinner. Since I had invested beaucoups in the paint job, I was determined not to scratch off my brand new paint! I got a soft diaper and dental bib clips:

I drop the edge of the diaper between the cowl and the spinner, secure it with the dental bib clips, and the top and bottom of the cowl will slide out from behind the spinner scratch-free!

By the way, even though the gap is tight, when under power, it probably widens a tiny bit with compression of the engine mounts. Jabiru USA includes engine mount spacer washers 1/8" thick. Pete at Jabiru USA said I may or may not get some sag of the mounts with time. If I do, he suggested using the spacer washers to restore an even gap. He also said I could put washers on all the mounts now and widen the gap, but I'm satisfied with it as-is.