Just purchased a Hangar 9 Extra260 27% . Would a Zenoah g62 be too much for this plane since I have one?

Yes.    A strong 33+cc should fly it . They say a lightweight 50cc also but I think that would be way overpowered too.  Maybe an engine around 3-4 pounds. The 62 is 5 pounds and just too big and powerful...in my opinion.

Thanks for your response.

I think the G62 is too big and heavy for that plane.. I am using them on my 1/3 scale Cubs that weigh 35 lbs or better .. I would use a G26 .. I am using the G26 on my 1/4 scale Cubs that weigh around 15 lbs .. a G26 would be a much better choice ..I do understand the reason you would like to use the G62 is because you have one but I think it would rip the plane apart...However I dont know the plane and how strong it is..It calls for a much bigger engine than I would have thought it needed.. A DLE 35 might be a nice moter too...they are little power houses ..