I would guess around 9 pounds. Plane is not featherweight by any means. The built-up wing is significantly heavier than the foam wing I had in my Diamant 90 although they are similar in area and size. I think the aluminum wing tube joiner and the retract hardware built in (wooden blocks, maybe plywood ribs) add some weight to the plane. The original landing gear is also on the heavier side.

What pipe and header are you using with your setup? Did you need to mount the engine on its side?