To be honest I dont know what a JS is but at .63 it sounds like a 4 stroke. IF that is I think its a bit too small. As for the 46AX i used a 12x7 on my Super tiger 45 and a 11x6 depending, so In both respects I think its too small of a prop. The 15x6 on the .91 maybe a bit too big but its worth a try it may work out. I had a OS 91 and used a 14X6. For extra speed I would go to a 13X8. And a 15x6 is s bit too small for the the YS 110 a 15X8, 16x6 or for 3D a 16x4W