ORIGINAL: Sprink
No, but 61s are a bit heavy for this, especially as you are already at 5.5lb (does this include the engine or not) I used a Saito 72 with 14x4w, went very well. Best two stroke would be the West 50 T1 - designed for funflys like this.
I should have stated that I estimate the all up weight at around 5 1/2 lbs. Thanks for the advice.[8D]