Today I just maidened mine I bought used... it had 1 flight on it and looked it... it was a VERY clean and new plane. I put an OS 1.60 FX with a Pitt's muffler... and a sonictronic onboard glow.
I balanced it per the Manual ( which I downloaded from Goldberg ) and set all the throws per the manual... and all I needed to do is to put a click of down trim on the elevator and it flew like a dream ! I am going to set the aileron low rates a tad higher... other than that... the stock setup flies it fine.
The 1.60 I have on it is brand new and had about a tank ran through it. As far as a 1.20 on it... I think it would be on the edge for power.... it would fly.... but not have the power to do basic aerobatics... just fly..... that's my opinion on that after flying it today. You will love the way it flies for sure there !