If you are thinking of OS 1.6 FX-FI it has good power but weights 33.3 oz (plus muffler) plus fuel + EC-2 CU plus bigger main battery (to power the fuel injection). OS doesn't say it, but you will end up with much more weight than with Saito 180.

Talking about OS 1.6 FX it weights 32.6oz plus muffler plus fuel. You see, the engine weights the same as Saito 180 but 4-stoke has only 2oz muffler, 2-stroke is 6 oz (as I remember right) or 8 if you take Pits style.

Other than that I just don't like big 2-stroke glow for 3D. Without a pump is so difficult to tune them right. They are so sensitive to everything. I don't know OS 1.6 FX but I had OS BGX and I just got tired of tweaking it all the time.

I looked at all (I think) possible engines and I didn't find any engine, that will run this plane with less than 3 lb (including fuel). It doesn't metter if it is 2-stroke glow, 4-stroke glow or 2-stroke gas (I don't even think about 4-stroke gas). The only favor of 2-stroke glow is the price. But then ST 2300 is better deal

RysiuM