COVERTDC3,

That seems like a lot but I've never had a kit come in at the stated weight. I have a 120 Corsair that is said to be 11lbs. but came in at almost 16lbs.
There was a review where a Zenoah G20 was used on the Sopwith and it balanced with that engine, and as I remember they to had to mount two batteries in the cowl. One was for the electronic ignition.
I have a Saito 91 in mine but I haven't balanced it yet. I just received my missing brass parts today and I hope to finish the wires this weekend. I do expect to be adding weight.