Having flown both planes quite a bit I can say the Hog will do fine with a four stroke, I ran an OS .91 in mine and was pleased with it but as mentioned it was a bit nose heavy. I probably wouldn't power it that way again. As for the Taurus I powered mine with an OS .61 FX and it was great. Big loops, good vertical for stall turns, top hats and M's. I would not put a four stroke in that one mostly because it wouldn't gain you anything and I'm not a YS fan anyway. In both cases I had no problems with vibration or with servo wear. Though I wouldn't do another Hog with a four stroke it sure did sound good cruising by.

Rick H.