RE: YS .63 will it run on 15%?
I've just got YS63S and ran 15% nitro and 20% oil from SIG for a few weeks.
I did not see any problem with 15% fuel. I have APC 13X6 prop running top end at 9300 RPM and idle at 2300 RPM steady. The power you can feel from going idle to top end is excellent. I am thinking about getting another one.
Yes 15% is OK