I think that the comments regarding the rare bear posted on this site are valid, however I think that Thunder Tiger would not have produced this model without testing it , and the limit is 61 to 90size two strokes. Mine is based on the TT90pro and its doing fine for me.
That said , it should withstand a fair bit more power without to much airframe stress. In its defence I think its a fantastic rendition of a fantastic aircraft and should be enjoyed within its limits. I have no doubt that as soon as you see it in the air you will be like a child in a sweet shop........IT WILL BE WORTH IT