RE: 86" Yak
I put an MVVS 58 Pro in the 85" with a cannister silencer and the batteries had to go just behind the wing tube, I think the 86" has an extended front section beyond the wing so the 58 may be a bit heavy with a cannister, but can't be sure of that assumption, however, the canniste is better for the Evolution or MVVS they need to have a free flowing exhaust to develop full power, not that the 58 lacks in that, most of my flying is done on half to threequater throttle as at full throttle its just an insane amount of thrust, but fun.
Mike