the smoke won't be as thick and puffy as what you see on gas engines but if you can get it to work reasonably well on a 46ax, like i have seen vids of and the smoke was faint but noticible enough to say "my plane has a smoke system". A 160 should work ok once set up right

have you thought of using just crankcase pressure it could work just as effective and you will be saving weight.

this said you could get a ys 170 and run it slightly rich and "wala" continious smoke system

46 on smoke
http://au.youtube.com/watch?v=nPdVIf2kpv8