ORIGINAL: flygilmore
I would deff. not use Karbonite gears in a gasser either-to much likelyhood of them shearing/stripping.
I would think the heavier duty Karbonite gear servos would be OK in these smaller gassers, especially on non 3D models that have smaller control surfaces. These engines run as smooth or smoother than similar sized glo engines .... smoother than most large 4 strokers. Just be sure not to get any LocTite even near these gears as this will cause failure of the output shafts. Of course, metal gears are always a good way to go.