tonealone...
Congratulations on getting this plane. I'll guess you'll really like it.
I tried the 16.5x5 prop. I acted good but was too much prop at my elevation. I couldn't bring it up to speed. So...my guess is it will work if you're close to sea level. If your high...you'll wanta go with the 16x6. Better fit.
Here's a link to the YS website including a download for the whooping 2 page manual.
Thanks
Barry
http://www.yspartsandservice.com/parts_ys110fz.php