The problem with those engines is the high rpm you need to get the power
power 10 kw 9000rpm
max rpm 13000 rpm
That is about 13.5 HP at 9k
don't expent that engine to last long cruising a 8000 to 9000 rpm
sound like fun till they puke.
i would bet you could get 15 HP plus fro mthe 185 with some tuned pipes and carbs re jetting and again higher rpms.
PROS vs CONS
Long Life ? OR lotsa power ?