The Hog in my avatar has an OS 70 Surpass I and a 13x6 prop. With 10% nitro, on grass, it takes off easily at half throttle. My plane weighs 7 pounds 14 ounces according to a fish scale. My plane is a tail dragger, originally built with the gear in the wing. The 3rd landing missed the runway and the tall grass broke a gear block loose. After I fixedthe wing I mounted a Dubro fiberglass gear in front of the wing saddle so I wouldn't damage the wing again on a rough landing. I cut in a piece of 1/4" aircraft ply on the bottom of the fuselage and ran a strip of fiberglass cloth from the firewall to the wing saddle for support. I doubt this gear block will ever get pulled off.