I'm scratch building a CG Sukhoi (72.5" wing) and would like to go gas. I was going to put an MDS 1.48 or OS 1.60 in it, but I want to go with gas if I can. How much is too much weight for a engine on this plane (949 sq"). I was hoping to use a magneto Poulan 46cc. About 3.5 to 4.lbs. The advertised weight of the plane "claims" 8.75 to 9.5 lbs.